Rocky, you are a genius. I failed smog test twice. Then watched your video and did what you said. Bingo! It passed Oregon smog test with flying colors. Thanks sooo much.
Greetings...diane good...…….You're welcome, and, Congratulations, for tellin' that smog sniffin' machine, who, the real Boss is now...!!!...lol...…….Me, a genius...???...nah, I'm just a part time Grease Monkey, that happens to have automotives, as one of my hobbies, that's all, and, just like, I've probably said a few times in the past, and that is, that, if someone is interested in a certain subject matter, then, it's pretty much a given, that, that person is gonna learn quite a bit, don't-cha-think...maybe...yeah, I'd say so...……..My very first attempt, to adjust the two idle mixture screws, that were on a 4-barrel Rochester carburetor, that sat on-top of a Chevy 350 cubic inch (5.7 liter) V-8 engine, (and, having no catalytic converter at all), was done, just by (my) ears (sound), of the engine, while it was fully warmed-up, and at (curb) idle speed...…….I turned both idle mixture screws in-wards (clock-wise), as much as I could, while still having, a really good sounding & smooth idle, along with, not noticing any miss-firing at all...and...I still received, that Big "Fail" word, printed on the smog testing paper...……...As I recall, at idle speed (only), I was just a wee bit too high, as in, oh, about, 700-plus, and the maximum was about 500 (high reading, was due to, what is called, a "lean-misfire", as in, not enough gasoline in the mixture, which, I didn't detect by ear/sound, and also, "not having", the engine shaking, what-so-ever)...so, not too bad, seeing as how, I didn't do the proper (idle speed) "lean drop" procedure, probably, because I never did it before!...lol)………..Then, there "it" was...Yes-Sir-ee-Bob, I finally saw that "Sticker" (label) that was stuck to the under-side, of the Chevy Van's hood...!!!...commonly, called a V.E.C.I. (as in, Vehicle Emission Control Information, I think?), and the "lean-drop" specifications, were on the sticker, the whole (censored word) time...!!!...lol...……...Perhaps have a look-see, in, or around, your vehicle's engine compartment, firewall, and/or, under the hood as well, and hopefully, if "it" is (still?) there, it won't be hiding, as good as a Sasquatch, is capable of doing...lol...……..The carburetor's idle mixture screw's adjustment, is just, one of many things, that can cause an engine, to Fail the smog/emission test, and it might (some day), turn out to be, a problem, with the ignition system, and can sometimes, result in, a weak or intermittent spark, showing up, between the spark plug's two electrodes, which usually sends, a certain amount of un-burned gasoline, right through, the vehicle's entire exhaust system, and, if really bad, it has the potential, to ruin/destroy, a catalytic converter (or two of them, if so equipped), and then, just repeat after me...expensive...Expensive...EXPENSIVE...!!!...so yeah, always keep vehicle Maintenance in mind, just in case, and...….till next time......Be Safe, take care, and have a good one.
+Erik Sanchez ....Greetings Erik Sanchez....You're Welcome, and..."Congratulations"...!!!...I say, for getting Your Thermoquad Carburetor equipped, 440 Cubic Inch V-8 Engine, to be able to "Pass" the Smog/Emissions Test, with the Adjustments that You made...(can You Hear All of the People Clapping in the background...???), oh, and, now that Your RV (Recreational Vehicle), has Cleaner Exhaust Gas, Exiting the Tail-Pipe, You might be having the onset, of a "Mosquito" Problem, when Ur Campin', now that Your RV's...Keep-the Mosquitos-Away-Stink-ee-Engine-Exhast-Gas...is Gone...!!!...lol...................Well, aside from a properly working and set-up Thermoquad Carb, there are a few more things, that have to be working correctly, and/or, adjusted properly/to specifications as well, depending on, just what, and how many, shall we say "Smog Devices", that happened to be Installed on, just about any given Vehicle, when it first, Rolled-Off-of-the-Manufacturer's-Assembly-Line.........................Here are some of the Smog related things, that I've noticed/observed/studied/fixed, and tried to fix...lol...over quite a few years.....................The Distributor's, Initial (base) Ignition Timing, has a lot to say, in respect to, what might be printed on the Smog Testing (paper's) Final (and maybe Not Passing) Result......................If the Engine has an EGR/Exhaust Gas Recirculation System on it, then, that EGR Valve & related System, has to be working really good, or, a Very High NOX/Nitrogen Oxide Reading, it will usually be, as I found out, by actually seeing, just how High the NOX Readings can get, on a Chevy V-8 Engine, that didn't have an EGR System on it, and is as follows......The Lowest NOX, I ever got, (on that particular vehicle), was about 1500 PPM/Parts per Million, and the Highest, was Above 3000 PPM, which, was about, the Maximum allowable, or, Fail, it was...Yikes...!!!.....................Now, I'll mention, some interesting Smog Results, that I got, After Installing, a New 3-Way Catalytic Converter, on a Mid-1990's, V-6 Engine...................Well, due to that old/high mileage, worn-out Cat (Cat = Catalytic Converter), I received that (not so much needed, or wanted) "Fail" Word, printed on my Smog, Test results paper, and, the Over-the-Allowable-Amount, wasn't all that much..........So, after gettin' Smog Tested again, with the "New Cat", I saw a Real Eye-Opener...!!!...Damn, the Smog Readings were about 1/2 (One Half), of the "Average Readings", that all of the Other Similar Vehicles were Getting...Holy-Gwalk-ah-Moly...!!!...now that's Impressive, and, just goes to show, just How Much Smog, a New, and Very Good Working, 3-Way Catalytic Converter Can Remove, when it does a Super Job...!!!.........................Oh, and, a 3-Way Cat, will reduce HC/Hydrocarbon, CO/Carbon Monoxide, as well as NOX/Oxides of Nitrogen...where as...a 2-Way Cat, won't be able to take care of/reduce the NOX what-so-ever, well, from what I recall, that is.............................While Camping, or being Parked somewhere, and, If You're having Problems with Bees, such as Yellow-Jackets or Wasps, getting too close for comfort, then, here's a real neat "Trick", that a Fellow Camper, was tellin' me about, and at the very same time, showing me as well, and is as follows....................Pour some Orange Crush Pop, or something like it, into a See-through, Plastic or Glass Dish, or what-ever, and Locate/Place it "Away From" All Humans and Pets...cuz...those..."Bees" are "Attracted" to "it", like You wouldn't believe...!!!.....................Thanks for tellin' me, about Your Success, and.........till next time.........Be Safe, take care, and have a good one.
wow man ur a great teacher, am about to adjust my boat Carter four barrel carb this weekend, I just order a tach dwell meter after watching this video I know in my hart I can do this. thanks
Greetings...mrbigs g..........I sure do appreciate, Your very nice comment my Friend, and, thanks kindly, for it, as well...........Seeing as how, You were sayin', that, Your Carter 4-Barrel Carburetor, sits on-top of an Engine, that's in Your "Boat", then, if it were me, I probably wouldn't bother, doing the "Lean Drop" procedure, with the 2 Idle Mixture Screws, as I was showing Folks (how to do), in this particular UA-cam Video of mine, and here's why...............Engines, be them, Inboards or Outboards, that are in/on "Boats", as far as I know, have Never, had to be Smog/Emissions Tested, oh, and, thank goodness for that...lol.................I would probably (just), adjust the Carburetor, using a Tachometer (or by using a Vacuum Gauge, will give about the same result), by doing the following..................Have the Engine Fully Warmed Up, and in "Neutral" (Out Of Gear...!!!), and make sure that, Cooling Water is Circulating, while the Engine is Running...............Then adjust the 2 Idle Mixture Screws "Equally", like I was showing (how), in this Video of mine, up to the point "Just Before", I did the "Lean Drop"...cuz, most Boat Engines, will probably, not do so well, with the "Lean Drop" (aka, "Leaner'", Idle Speed, Air/Fuel Ratio/Mixture)..........The "Lean Drop" Method, that I was showing, in this UA-cam Video of mine, had to be done, to get the Car or Truck to "Pass the Smog Test", so then, Boats, need not apply...lol (I think...???).................You can try doing the "Lean Drop" procedure/method, if You care to, and if it does work, without having the Engine "Stall", when the Shift Lever is placed in Forward or Reverse Gear, then, Fuel Consumption, while the Engine, is at Idle Speed, might be a bit better...maybe (with a Boat, it's almost like sayin', Gallons-per-Mile...lol...well, maybe not quite)...............Keep an eye on, Water/Condensation in the Fuel system, as in...in the...Gas Tank...Fuel Lines & Fuel Filter...and the Carb's Float Bowl as well, cuz, Engines, really, don't Run so good, on H-2-Oh/Water...................Due to the rather high Humidity/lots of moisture in the air, that a Boat is exposed to, it's a good idea, to keep an eye on, all of the Electrical Connectors & Connections, cuz of...Corrosion...Oxidation...and sometimes, I've even seen...Green Yuck-ees...too...!!!...which on a bad day, will make for, some very Un-Wanted, Electrical, related Problems, and I hope not.........If You have a Distributor in/on Your Engine, I'll (almost...lol) Bet, that, there "Won't Be", a Vacuum Advance Unit/Canister on it, and it's probably, cuz, once the Shift Lever is placed in Gear, well, with a Boat, it's kinda like..."Going Up a Steep Hill...All of the Time"...!!!...(due to the high load, that the "Prop/Propeller", places on the Engine, as well as, a pretty much, 1-only-Gear-Ratio as well, most times), as opposed to, driving a Car or Truck, which in most cases, does just peach-ee, and gets better cruzin' gas mileage, with the correct Vacuum Advance Unit/Can on the Dizzy (aka, Distributor).................Make sure that, Your Carburetor's Idle..."Speed"...Setting, "Is Not" too "High" in RPM's, cuz, if it is, when going from Neutral, to, In Gear, it might go "Bang"...!!!...and that's not good at all................Then, there's the..."I'm Going Too Fast (at Idle speed...in gear), as I'm approaching the DOCK"...!!!...Yikes...!!! (might be worse than, Forgetting to put the "Drain Plug", back in the Transom..."Before"...the Boat gets Launched, into the Water...!!!...oh, and, if that happens, it will usually make for, some rather good entertainment, for the Folks at the boat launch/ramp, watching "it" happen...!!!...lol for Them, not so much, for the "Owner" of the Boat...!!!)............If You can find the "Specifications", for Your "Exact"...Boat...Engine...Out-Drive/Leg, or whatever You have there, then, all the better...........If You care to, You can let me know, how Ur makin' out, and if need be, just let me know about, any problems that You encounter, along with, the particulars of Your Boat, and.........till next time...Captain........Be Safe, take care, and have a good one.
Thanks for the thorough tutorial. I will be trying this today on my 79 440. I don't need to pass smog I just need it to run well and get the best gas mileage I can.
Greetings...Jesse Metcalfe...........You're welcome, and, thanks for watching...........Well, for starters, have a look-see, in Your vehicle's engine compartment, for, what is known as, a "V.E.C.I." (Vehicle Emission Control Information) Label/Sticker, as it will usually have, some very useful information, printed on it, and, in some cases, if not followed correctly, can sometimes, lead to, an Engine, that won't run very good at all...............Seeing as how, You were sayin', that Your vehicle, had a 1979 440 (big block) V-8 Engine in it, has me thinkin', that, You might have a Carter Thermoquad 4-Barrel Carburetor, that, may very well, have some additional, Smog Control Gadgets/Gizmos on it, quite possibly...???...and, if so, then, depending on, just which Model of Thermoquad (carburetor), it happens to be, then, sometimes, things can be easily adjusted, and other times, not so much.............If Your engine has a Thermoquad carburetor on it, then, there are usually...4 Numbers, with the letter S at the end of those 4 numbers, which will tell us, what the Model, actually is............You can find/see, these 4 Numbers, followed, by the letter S...Stamped into, the Base/Lowest part, of the Thermoquad carburetor, on the Left, Rear corner (as viewed, while, You are sitting in the drivers seat, as an example)............If You can tell me, what those 4 Numbers are, that are followed, by the letter S, at the end, then, I'll do what I can, to help You out, and, if You have another Type/Brand of Carburetor, on Your engine, just let me know, what the Make & Model Number is, of, what-ever, it just might be...thanks, and........till next time.......Be Safe, take care, and have a good one.
Hey Rocky! This is Ben from Berlin/Germany. Thanks for your tips and your patience! I just rebuild my TQ following your detailed descriptions. It is a TQ 9211S, which sits on a Dodge 440(-3??), 727 trany, in a 79' Dodge MB400 Chassis Motorhome. The Carb is an all mechanical model with no solenoids what so ever. Like advised by you, it got every gasket in new, brand new X-Rings, brass floats, new choke pull off. All parts where dry ice blasted and ultrasonic cleaned before reassembly. Just to let you know that I tried my best to work accurate. ;) Today I tried to adjust the idle mixture screws following your instructions above, but to my major frustration it didn't work at all. Basic set up: idle mixture screws 3 turns out from fully in, idle at 950 rpm while in (D), parking brake on. (to bad, but the V.E.C.I. sticker seems to be long gone) But there was no increase of rpm when I turned the screws in slowly. In fact, the rpm slowly dropped while turning them in, until they were fully closed. Do you have any idea where my mistake could be? Could a contamination at a certain point cause such a behaviour? Could the fuel level be to high? The floats are set to 29/32 from the gasket surface, I have not checked the wet fuel level. Tomorrow I will try to find out if there is a vacuum leak by spraying some brake cleaner around. Appreciative for every hint-> ben
Greetings...Ben/heinz wurzt..............Thanks for watching, and, I'm sorry that I took so long, to give you a reply..............That "Lean Drop" method, that I was showing in my UA-cam video, really only has to be done, if, the Vehicle has to go through Emissions Testing (smog testing)...............If the Vehicle "Does Not" have to be emissions tested, then, as long as, the two Idle Mixture Screws, are set, at the point, where the Highest RPM's are found, while at idle speed, then, that should work really good (providing that, everything else, is working as it should be)..............There is, a, shall we say, sweet spot, as it applies to, the setting of, one or more idle mixture screws...............(the following, "does not" use that lean drop method at all, and also, the engine is fully warmed up to operating temperature, and the choke is fully Off).......Let's say, for instance, that, an idle mixture screw, is already "Set" at that sweet spot, as in, Highest engine RPM, while at idle speed, then, when that idle mixture screw gets turned, either "clockwise", or, "anti/counter-clockwise" (as in, in or out), then, the engine RPM's should start to drop (cuz, the idle mixture screw, is no longer set at that sweet spot, that I was mentioning), or, it might not drop all that much, when going Richer/turned out..............Using a Tach/Tachometer, is just one way to make the idle mixture screw adjustment...............The, shall we say, old school guys, that worked on the much older (and much simpler engines), would probably be using a "Vacuum Gauge", that was hooked up to the intake manifold (vacuum signal), to make the idle mixture screw/screws adjustment.............Having the engine fully warmed up to operating temperature/choke fully off, and at idle speed (I'd do it in Park/automatic, or Neutral/standard transmission, with parking/emergency brake on/wheels chalked with bricks or lumber for safety), then, just turn the idle mixture screw, or screws, as the case may be, in or out, until I saw the Highest "Vacuum" reading, on the Vacuum Gauge's dial, that will probably have, the dial on the vacuum gauge, indicating in Hg (Hg = inches of mercury, as I recall).............Try making the idle mixture (screws) adjustment, while having the automatic transmission in "Park", with engine fully warmed up/choke off, cuz, I'm pretty sure, that, You'll probably even "Hear" the changing engine RPM's, cuz, the engine, will be, shall we say, Free-Wheeling, as opposed to, having, quite a Load, imposed on it, cuz of that automatic transmission/torque converter, making the engine RPM's "Drop", and, will probably also, kinda interfere, with the idle mixture screw/s setting some-what (Yes-Sir-ee-Bob, that's the way I be thinkin' alright...lol)..............So, try doing it in "Park", and, if You care to, You can let me know, how You made out, and if need be, we can try a few more tricks (so to speak)............Good Luck, and......till next time......Be Safe, take care, and have a good one.
Thank you for this instruction video -- I am installing a new Qjet for a 454 and this is the first clear and easy to understand procedure I have yet to see. I have always had problems with the fine tuning, I do a pretty good job but now I see how to get it right on the money -- thanks again. When I get the job finished I will let you know how it turns out. thanks again.
Greetings Dan Baxley....Thanks for watching this video, and, thanks kindly for Your much appreciated comment....The "Actual" way, in which I was showing people how I Adjusted the "Idle Mixture and Idle Speed" in this particular video, "ONLY" Applies to a Thermoquad Carburetor, similar to this one, and, also "Specifically" to the "Exact" Engine (Dodge 360 Cubic Inch V-8) that, the other similar Thermoquad Carburetor, was installed on, as per the "Specification's" on the "V.E.C.I. (Vehicle Emission Control Information) Label", that was stuck in that Vehicle's Engine Compartment was showing....Although the "Method" that I was showing People, that I used, in order to "Pass" the "Smog" (aka, Emission's Testing) for this Particular Engine and Carburetor "Combination", can, sometimes be Successfully used, on quite a few Engines, with 4 or 2 Barrel Carburetor's, If, the Engine/Carburetor "Combination", are of a "Stock" (aka, Factory, Unmodified) Nature. I have done the very Same "Procedure" (Method), with a Factory/Stock (No Modification's) 1979-350 Cubic Inch (5.7 Litre) V-8, that was Equipped with a "Quadrajet" Carburetor, with a Turbo-350-Automatic Transmission, but, with "Different" Engine RPM's (Revolutions Per Minute) Specification's, when "Performing" the "Lean Drop" Method. If Your Engine have been "Modified", especially, with a "Lumpy & Aggressive" Camshaft, then, this good ole "Lean Drop" Method, as I see it, probably Won't Work. If, Your Engine is Stock, Unmodified, and has the factory Installed "Pollution Devices", connected and working properly, then, I figure that, the vehicle Would stand a much better chance at "Passing" the Smog/Emission's test. Here's an Example of the "Figures" that I used on that previously mentioned 350 Cubic Inch Chevy V-8, that was Adjusted for Smog/Emission's Testing... "Please Note", that the following Specification's "ONLY" Apply to this particular Chevy 350 Cubic Inch V-8...!!! Engine fully warmed up... Automatic Transmission in "PARK"...(and on level ground, with the parking/emergency brake On, and with, Wheel "Chalks", well actually Bricks, blocking all 4 Tires, to keep the Vehicle from takin' off!). "Stop Engine", then, set the "2" Idle Mixture Screws "3" Turns Out, from being just "Lightly Seated". Re-Start Engine, and Adjust the "Idle SPEED Screw", so Engine Idles at 875 RPM's... then, turn each of the "Idle MIXTURE Screws" In or Out, in order to make the Engine Rev at the Fastest RPM's...(I ended up with each of them, being about "4" Turns Out, from just being Lightly Seated). ...The Engine's (875 RPM's that were Initially Set, will probably "Change" to a Different RPM!), so, just "Re-Adjust" the "Idle SPEED" Screw, back to "875" RPM's....I had to do this a few times, to get it "Fine" Adjusted. ...then, once I got the Fastest Engine RPM's at that 875 RPM's Dialed In (about "4" Turns Out, from being lightly seated), I Turned, "Each" of the "2"..."Idle MIXTURE Screws" in "EQUALLY", a bit at a time (same amount of Turns and Partial Turns) until the Engine RPM's "DROPPED" to 700 RPM's. So, in essence, I went from "4" Turns Out (from both idle mixture screws being lightly seated), and having the 350 Chevy Engine, running at its Fastest (Idle Mixture) Speed (at 875 RPM's), and, I "Lean Dropped" it to 700 RPM's, which required that, I "Turned In" the"Idle MIXTURE Screws" about 1 1/2 (one and one half) Turns Each, from the Original "4" Turns Out (from being lightly seated), then, those "2" Idle MIXTURE Screws, ended up, being about 2 1/2 (two and one half) Turns Out, from being lightly seated, as the "FINAL" Adjustment! I actually Confirmed that 2 1/2 Turns Out, with "Both" Idle MIXTURE Screws", from being lightly seated, by, Marking them with White Chalk, and Turning them in, until lightly seated again, then, I backed them out, to that "Lean Drop" Setting, that I marked with "White Chalk", back to the 2 1/2 Turns, from being lightly seated, and made sure, that I made the "Finished" Adjustment, while turning Both Idle MIXTURE Screws in a "Clockwise" Direction! (so the "SPRINGS" on the Idle MIXTURE Screws "Don't" decide to "Adjust" the Idle MIXTURE Screws, when I'm Not Looking!!!).. ...also...there is really No Need to lightly seat the "2" Idle MIXTURE Screws, again, like I did, as I Only did that, cuz, I was really Curious, as to, Actually, How Far Out, the "2" Idle MIXTURE Screws were, from being lightly seated! In a Nut-Shell...With the Automatic Transmission in Park, I got the (warmed up) 350 Chevy Engine, to Rev its Fastest, at about "4" Turns Out, (875 RPM's), then, "Lean Dropped" it, down to 700 RPM's, by turning "IN" Each Idle MIXTURE Screw, about 1 1/2 Turns, and ended up with having Both Idle MIXTURE Screws Out, about 2 1/2 Turns, from being lightly seated, for the "Final" Setting, as per the V.E.C.I (Vehicle Emission Control Information) Stickers, Required "Lean Drop" RPM's Specification. If Your 454 Engine equipped Vehicle "Does Not" have to go through the "Smog/Emission's" Test, then, the "Idle MIXTURE Screws" for the most part, can be Adjusted, so, Your Engine gets the Fastest RPM's at the (Curb) Idle Speed, that Your Engine Specifies... ...You can do the "Leanest" Idle Mixture Screws Setting, while the Vehicle is in Park (Automatic Transmission)... To set Your Vehicles "In Drive" (automatic transmission), "Curb" or "Final" Idle SPEED", is to simply "Set" Your "Idle SPEED" about 100 RPM's "Higher", while You have the (automatic transmission) In "PARK", then, get in Your Vehicle, and, hold the Brake on, as You put the (automatic transmission) In "DRIVE", and see what the Idle SPEED RPM's are at. If You need to Adjust the Idle SPEED any further, just put the (automatic transmission) back in "PARK", and Re-Adjust Your Idle SPEED Screw accordingly, and, get back in the Vehicle, Brakes On, put the (automatic transmission) In "DRIVE" again, and, repeat, the above sequence if needed... ...Don't Forget, to put the (automatic transmission) back in "PARK" when You're Finished!!! (and the Brakes On Too!!!). Your Engine might Require a Slightly "Richer" Idle Mixture, to get it to "Idle Smoothly", as Engines are somewhat like People, in that they seem to have "Individual Personalities" as well...!!!...lol. Just keep in mind, the "Leaner" that You "Set" Your Carburetor's Idle MIXTURE Screws (to a certain point, that is), the "Less" Gasoline, that Your Big 454 Cubic Inch will be "Guzzling" at all of those Red Lights and Stop Signs, because "All" Gasoline Engines (while running), with the Vehicle "Not" in Motion, will tend to get... ..."ZERO" Miles Per Gallon!!!...or...in some cases..."ZERO" Kilometers per Litre!!! If You like, let me know, what Testing, if any, that Your 454 Cubic Inch Engine, has to be subjected to, as in Smog/Emission's Testing, and any other applicable Inspections, that way, I'll know what will help You out the most. Till next time... ...Be Safe, take care, and have a good one.
RockysRoadshow Teh 454 Chevy engine I have is in a 30 motorhome I had it completely rebuilt (stock). Even repainted Chevy Orange. I has about 8,000 on it and I had originally put an Edelbrock 1411 on it, replacing the stock QJ, but guess what, in california the E is not approved, even though you can buy these carbs at Pepboys -- well it would not pass smog because the carb was not approved. Luckily I still had the original QJ, and with the carb I was getting a reliable 8-9.5 mpg. After the rebuild with the Edelbrock the best I could get was 7.5, mostely 6.5, so going back to the QJ I figured would be a plus but 30 year old carb (?) so the smog guys rebuilt it, installed it and it passed smog. That was 2 years ago and after the QJ rebuild the mpg was not any better than the Edelbrock. The QJ seemed to climb the hills better than the E. So, two weeks ago I had to go to smog it again and it passed, went to a different shop, and got the specs back and was told it barely passed, just barely, the emphasized. They told me it was burning all of the fuel, running too rich. The engine, however, has been running really sweet, smooth idle and just purring down the freeway, but the MPG still not as good as before on the pre-rebuild and old QJ. This all led me to decided to forget about messing with the carb anymore so I bought a NEW, Rochester QuadraJet, 800 CFM from Jet Performance and it has all of the Smog fitting required by California smog. It is a 2 Stage model and the bottom plate, where the Mixture screws are located but they are recessed and look like they take a special tool to adjust. I did pull the old plugs and installed new ones -- that was a job. And I replaced the HEI cap and rotor with new. Now I am getting ready to install the New Crab. Here is the reading from the smog station -- This is all greek to me, just going on what they said.-- at 704 RPM HC (PPM) AVE: 57 -- MEAS 71 The CO (%) AVE .70 -- MEAS 1.06 -- at 2478 RPM -- HC (PPM) AVE 33 - MEAS 21 -- The CO (%) AVE .30 - MEAS .91 It passed so I am happy about that, so i have two years before I have to do this again but i wanted to know how to set up thin new carb and that is when I found your posting, love it, cleared up a lot of misdirections finding at other places. Any advice is really appreciated. Thanks for being there Rocky
Dan Baxley Greetings Dan Baxley....You're welcome, for...my being here, there, and almost everywhere...lol...and, thanks for Your nice comment, my Friend....First thing I should mention, is, about Your newly acquired "Jet Performance 800 CFM Quadrajet Carburetor, and, about what You said, about, needing to have a "Special Tool", to "Adjust" the Idle Mixture Screws....Drum Roll Please...It so happens, that I have a UA-cam Video, on How I made my Own..."Special" Idle Mixture Screw "Adjusting Tool", and hopefully, the Idle Mixture Screws, in Your new Jet Performance Quadrajet, has Similar "Heads" on the Idle Mixture Screws, as can be Seen, in the UA-cam Video that I made a while ago... Dan, you can find the UA-cam Video, that I just mentioned above these words, on my UA-cam Channel...RockysRoadshow...and, the Title of that there Video is called...Rochester Quadrajet Dualjet Idle Mixture Plug Removal, Plus "Special" Tool!!! Maybe, have a look at my UA-cam Channel...RockysRoadshow...and You may very well, Find some Helpful, and perhaps Educational Information, that is contained in those very Videos...Enjoy. Oh, where to start... A Person, always has to remember, that, the Gasoline that is being sold these days, for the most part, is being "Blended" with "Ethanol" (aka, Alcohol), which usually causes Carburetors, that were "Calibrated" for that good ole Gasoline, and for example, using a Carburetor, of oh, about 1974, let's say, would more then likely, cause that 1974 Carburetor, to be administering a "Leaner" Air/Fuel Ratio, to the Engine, because, the Higher the %-age (per-cent-age) of Ethanol in the Gasoline "Blend", the "LARGER" the "Fuel Jets" usually have to be, and, in some cases, to prevent "Lean Surging", as I have experienced in the past. It would help, if I knew what "Year" Your Motorhome and Engine happen to be, because, of the Many "Different" Types, of applicable Smog Equipment & Devices that were Installed on Your 454 Engine, as well as, what "Type" of Catalytic Converter was installed..."2-Way" or "3-Way ??? (if there is one, that is). EGR Valve? (aka, Exhaust Gas Recirculation, and, there are many Variations of this Device as well). Air Pump (aka, Smog Pump) ? Then there are all kinds of Vacuum Devices, such as Delay Valves, Thermally activated (coolant) Vacuum controls, and, the list goes, on and on... Sometimes, as with Your "Original" Quadrajet, the "Nitrophyl" (black plastic Float) has been known, to "Absorb" Gasoline, and this will cause Your Float, to start "Sinking", which will cause a Very "Rich" Air/Fuel Ratio, and may very well have been what caused Your Original Quadrajets "Rich" running condition. Not to mention, that, a "Dirty" Air Filter, will also cause a "Rich" running Carburetor, due the the "Air Flow Restriction", that it causes. (the Engine has to "Breathe!"...lol)...and...Your Engine Needs a Nice "New" Air Filter, to help make Your 454 Engine "Pass" the Smog/Emission's Test! Your Fuel Filter/Filters, have to be Like New, and Not Plugged Up in any way, or, it is possible, that it will cause Your Carburetor to run "Lean" (air/fuel ratio), which may very well cause, what is termed, a "Lean Miss-Fire". A "Lean Miss-Fire", in most cases, will usually Send "Unburned" Gasoline through Your Exhaust System, and, The "Smog-Sniffin' Machine will usually "Detect' and "Report" a higher then wanted High "HC" (Hydro-Carbon, or just basically, Gasoline that wasn't completely Burned). If You happen to "Set" Your Idle Mixture Screws "Too Lean", this will also cause a "Lean Miss-Fire", so, don't be tempted to go to "Lean" when setting them. Even though, that "New" Jet Performance Quadrajet, that You have there, that has the Correct "Exterior" Fittings and such, might help Your 454 Engine to Pass the "Visual Test", it won't Guarantee, that the "Calibration" (aka, Fuel Jets Sizes, Air Bleeds, Float Level Setting, etc.) will be Set-Up in the way, that is required, in order to "Pass", that, good ole Smog/Emission's Test....Only, the Smog/Emission's Test Itself, will determine that, Your New Jet Performance Quadrajet is Set-Up, and, Calibrated Properly, to keep the Engine's Exhaust Emission's at a "Pass-able" Level. If Your Motorhome Has a "Catalytic Converter", it has to be "Functioning" Like New, or, that Smog-Sniffin' Machine will let You know. You had mention something about a "2-Stage-Model" ???....I'm not sure, just what You mean by that, perhaps, let me know, if You care to. Before You Installed the "New Spark Plugs", did You "Set" the Spark Plug's Gap? (between the 2 Electrodes). I have a UA-cam Video on, "How To Set The Spark Plug Gap" as well. Those Smog Numbers that You posted, look to be, not too bad. I did notice, that You indicated CO% "Twice", with Different Numbers. I'm thinking that, one of them is, "NOX" ? (aka, Nitrogen Oxides). Here's some Food For Thought... "HC" is short for Hydro-Carbons....Simply put, just Unburned Gasoline. "CO" is short for Carbon Monoxide....Carbon Monoxide is Lethal (aka, Deadly)...!!! If Inhaled, it enters the Bloodstream, and "Prevents" the Blood from Carrying "Oxygen" throughout the Human Body, and, basically, a Person "Suffocates" (Internally), and, if Inhaling too much of this Deadly Gas, that poor Person "Dies"...!!! "Always" have Plenty of Ventilation (aka, Fresh Air), whenever "Any" Fuel Burning Engine is Running...!!! "NOX" is short for Oxides of Nitrogen....The "X" denotes, that there are more then "1" Type of Nitrogen Oxide, in this Mix. NOX is the result of, what is normally referred to, as, "Peak Flame Combustion", or in simple terms, When Very High Temperatures Occur in the Combustion Chamber/s, as the Air/Fuel Mixture is Burning, which in turn causes the excessive NOX. To combat this NOX stuff, they came up with a few things. EGR System, (Exhaust Gas Recirculation), which includes the EGR Valve itself (the Older Ones, kinda look like a little Space Ship...lol). When the Engine was fully warmed up, and at light throttle, while mostly Cruising along, the EGR Valve would allow Exhaust Gas (from the engine), to be introduced, along with the Air/Fuel Mixture, that the Carburetor provides, thus, basically, "Diluting" the Air/Fuel Mixture, in order to Keep that "Peak Flame Combustion Temperature" Down, to "Reduce" the Amount of "NOX" that starts heading its way, out of the Engine, and out through the Exhaust System. Hmmmmm, maybe I should make some kind of Smog video...?...lol. Have a look see, in or near Your Engine Compartment, for a V.E.C.I. (Vehicle Emission Control Information) Sticker/Label, as, that will be of some Major Help! Till next time... ...Be safe, take care, and have a good one.
RockysRoadshow Thanks for taking the time -- the motor is a 1983 454 Chevy, in a 1984 Revcon motorhome. No cats -- dual exhaust. I returned the Jets Quadrajet, turns out it has every thing but the goose neck in the throttle linkage, drivers side, to accommodate the TRC throttle lever actuator which appears to be an intricate part of the Emissions on this engine. I finally found out it is a feature put on some big trucks and mothers homes but seems to be missing on most cars of same vintage. So, I am stuck.. Originally when the engine was rebuilt I had an Edelbrock manifold and an Edelbrock 1411 carb installed -- the carb did not pass smog because it was not an approved carb. I'm thinking about putting it back on and then when smog time come around again (2 years from now) I will swap it back out for the old original Quadrajet? So, would the set up for the Edelbrock 1411 be the same as you demonstrate in the video? Also, should I put a heat shield gasket down under? And if it is a good idea to put a heat shield insulator gasket under this carb, should I also use the metal plate Edelbrock has for converting the Edelbrock Performer manifold with top cut for a Quadrajet, or can I just use the heat shield gasket? Thanks, Dan I am going to check out more of your videos -- love the detail.
Dan Baxley Greetings Dan Baxley....Seeing as how Your (Original) Quadrajet carburetor is a 1983 Model, that alone, has me thinkin', that it may very well be, something along the lines, of being a "Feed-Back" Type of Quadrajet, with Extra Gadgets, and also, an ECU (Vehicles on-board Computer) perhaps?....But sometimes, Trucks, and maybe Motorhomes as well, might not have been equipped with this Feed-Back Carburetor System, as the Cars were, during that time period....If You take a look, usually on the Driver's Side, of the "Original" Quadrajet, You should be able to see some "Numbers" Stamped on it....If You could tell me what these "Numbers" happen to be, I just might be able to find out, what "Gadgets" and such, that were Engineered in to it, by the Factory that made it in the first place. Did You look around in Your Motorhomes "Engine Compartment" (or anywhere in Your Motorhome) for a "V.E.C.I" (Vehicle Emission Control Information) "Sticker/Label" at all yet??? That VECI Sticker/Label, might just be, Worth, its weight in Gold! There is some Important Information on that thing! With Your Edelbrock Carburetor, the most "Important" thing is, to "Make Sure", that when Both, the Primary and Secondary Throttle Plates (aka, Butterflies) are "Opened-Up", as far as they will go, as in Full Throttle (aka, Pedal to the Metal), that Both the Primary and Secondary Throttle Plates "DON"T" get hung-Up, or hit any part of the Intake Manifold, or the "Adapter", if You so choose to Install one, between the Top of the Intake Manifold and the Bottom of the Carburetor! I know that most Quadrajets, that I have seen, are known as "Spread Bores" (Smaller Primary Throttle Plates, with Larger Secondary Throttle Plates)... ...where-as... I'm thinkin', that the Edelbrock, is referred to as, a "Square Bore" (carburetor), and that just means, that, "All-4" Throttle Plates, are the Same Size. It is Always a good idea to "Insulate" Engine "Heat" from the Base of a Carburetor, "Especially" if, the Carburetor is made of "All Metal", and also, given the "Confines" of the Engine Compartment that is found in Motorhomes and Vans, that Don't Allow as much Cooling Air, as most Cars seem to have. When an "All Metal" Carburetor gets Too Hot, the Gasoline becomes Less Dense, making for Less Power, and might even cause Vapor Lock, which has been know to cause poor performance, and hard starting too! If not being Smog Tested, You can simply Adjust Your Idle Mixture Screws, to give the "Highest" RPM's, at about, something like 700 RPM's in PARK (that 700 RPM's get dropped back by the Idle SPEED Screw, each time the Idle MIXTURE Screw/s make the RPM's go Higher, that the 700 RPM's "SET" by the Idle SPEED Screw.)...or...for Less Fuel Consumption, You could do a "100-RPM-Lean-Drop" (with the "2" Idle Mixture Screws), so You end up with 600 RPM's, "WITHOUT" Touching the Idle SPEED Screw. (go In Equal Amounts with Both Idle Mixture Screws, to get Any Lean Drop Setting). The Above Lean Drop Setting/s, may, or may not, allow Your 454 Engine to Idle "Smoothly". (Remember to Always make Your Idle Mixture and Idle Speed Settings, with the Engine Fully Warmed Up, and with the Automatic Transmission in PARK!) Just simply, Slightly "Richen", Both Idle Mixture Screws, an Equal Amount (opposite of a lean Drop...lol), until, Your 454 Engine is, Idling as smooth as Silk, or if not, at least in the same Ballpark, and remember to Re-Set Your Idle Speed accordingly. Check Your Idle Speed Specification, and hopefully, You will find that Specification, on the VECI Sticker/Label, that should be Stuck somewhere in Your Motorhome. Once You are satisfied with Your Idle Mixture Setting, just Set Your Idle SPEED Screw about 100 RPM's Higher then the Idle SPEED that You want, (when) the Transmission is in PARK...then, when You step on the Brake, and put the Transmission in DRIVE, Your Idle SPEED (while in DRIVE), will Drop in RPM's, and should be pretty close...if not, put the Transmission in PARK again, and Re-Adjust, then Check Idle SPEED in PARK again, with the Brake On...then just Smile! Be careful, especially if Your Original Quadrajet carb was Computer Controlled!!! You don't want to "Fry" any of the Electrical Components, including the Motorhomes Computer (if it has one, that is), by leaving Wiring and Connectors Un-Attatched, and maybe Shorting to Ground, or causing an Electrical Strain, by having something Disconnected! In other words "Look before You Leap!" (aka, do some Research, before You Modify Anything!). I hope that, all goes well... Be Safe, take care, and have a good one.
Greetings...p costa...…….You're welcome, and, thanks for watching...………Well, I kinda learn as I go, and, I learned quite some time ago, just how, to do this particular procedure, which I know, really does work, cuz, if Ya don't do it correctly, then, that smog-sniffin-machine, at the smog testing station, will probably be printing that Big Fail word, on the test paper results…!!!...lol...and.....till next time......Be Safe, take care, and have a good one.
+Ascended696 ....Greetings Ascended696....Thanks for watching...............You're welcome, and I'm glad, that this, shall we say, Generic way, of basically setting a Carburetor's Idle Mixture Screw/s, just might help, reduce the amount of Smog, that spews out of a Vehicle's Tail Pipe/s, enough, so the Smog/Emissions Test Paper, ends up having that nice "Pass" (stamp of approval) printed on it (hopefully)...and..........till next time.........Be Safe, take care, and have a good one.
Greetings...mrjacplumb………...Thanks for the nice comment, and thanks, for watching too...…...Me a genius...???...nah, more like a guy, that cracks too many corn-ee jokes, along with, a somewhat, over-active imagination, most of the time, I be thinkin'...…….Lem-me-see now, hmmm...4x2 setup...???...…….Would that be....two, four barrel...carburetors, that are mounted, on top of, the specific type of intake manifold, having, one, in front of the other one, which is commonly referred to, as being a...dual quad...(carburetor setup)...perhaps...???...……..Here are a few things, that might help you out...……If the vehicle "does not" have to be smog tested, then, it will be much easier to adjust the idle "mixture" screws (if Ya have to go through the smog test, then, just let me know)………….If "both" carburetors, provide the air/fuel mixture at idle speed, then, keep in mind, that, the idle mixture screws should be adjusted about the same turns out, from being lightly seated in the carburetor, to keep things, relatively balanced, so to speak (also, as I recall, there are certain, dual quad applications, where, the intake manifold runners/tunnels, might not flow, the air/fuel mixture "equally", to each of the engine's cylinders, which might have, some cylinders, running leaner or richer, than, some of the other ones, and, if this is the case, then sometimes, one or both four barrel carbs, might have fuel jets, that have different orifice/hole sizes, on the left or right side of the carb, so that, the air/fuel mixture, will end up, being about the same, inside all of the engine's cylinders, oh, and, if too lean, of an air/fuel mixture/ratio, in any of the engine's cylinders, while going pedal-to-the-metal, then, that alone, can destroy, that poor ole engine...!!!)………….I was just telling You, what I did, just in case, the idle mixture, that, the carbs deliver, might not be, shall we say, "balanced" (aka, equal), in each of the engine's cylinders...……..If not being smog tested, then, I would just use, an engine..."Vacuum Gauge"...to adjust the idle mixture screws (if you are running a, shall we say, aggressive camshaft, then, there are some other things, that will have to be taken care of, as well)……….First thing, is to decide, just what, your...Idle Speed...will be...???...then, continue on (please note, I always set the idle mixture screws, and, the idle speed screw, while the automatic transmission is in..."Park"...for safety reasons, and also, have plenty of fresh air/ventilation, around the vehicle, when the engine is running, or, Ya might die, because of poisonous fumes...!!!)………Here's an example for Ya...…….Having the engine fully warmed up/choke off, I want to end up, having an in-drive (automatic transmission), idle speed, running at 600 RPM's (stock, not modified engine)...so then, I set the idle speed to 700 RPM's in Park, to do the vacuum gauge, idle mixture screw adjustment (I'll later address, that final in-drive idle speed)………..What I'm aiming for, is to get the "highest reading", showing on the "vacuum gauge" (this usually means, that, the carb's throttle plates/butterflies, are closed, as much as possible, hence, the highest vacuum reading, showing on the vacuum gauge, oh, and, after all, when Ya take away, the carburetor & gasoline, then, the engine, really is, just a big ole air pump, when Ya really think about it).........The idle "speed", might go higher or lower, when adjusting the idle mixture screws, so, just re-adjust the idle "speed" screw, back to, 700 RPM's, then, re-adjust, the idle "mixture screws, for the highest vacuum gauge reading (it's sure is fun, tryin' to explain, how to git-er-done, using only words...lol)………..When all of the idle "mixture" screws, are adjusted, resulting in that, good ole, "highest", vacuum gauge reading, then, it's now time, to adjust the final "in-drive"...idle "speed" (please, pay close attention, to those two words, being, idle "mixture", and, idle "speed")……….So then, assuming that, we now have the highest vacuum gauge reading showing on the gauge, while having the automatic transmission in "Park", and engine is idling at 700 RPM's (engine at operating temperature/choke fully off), then, all that's left, is to end up, having the engine idling at 600 RPM's, while the automatic transmission is in "Drive" (example only...!!!).........Engine idling at 700 RPM's...Foot on Brake...put in Drive, and using a fairly accurate Tachometer, see what the RPM's are...???....too high, or, too low in RPM's, then, always make the idle "speed" adjustment in "Park" (again, I say...for Safety reasons...!!!)...then, foot on Brake...put it in Drive, and see what the Tachometer (aka, Tach), is reading, and repeat, if need be, until Ya end up with that (example only...!!!)...600 RPM's in Drive..........So then, You decide, what the RPM's will be, at idle "speed", when the auto-trans is in Drive (when the engine, is fully warmed up to operating temperature, and when, the choke if fully off), and just go about 100 RPM's, "above", your "final" idle "speed", to make those (now famous...!!!...lol), idle "mixture" screw adjustments..........If what you see here, isn't enough for You, to git-er-done, then, just give me a shout, and I'll see what I can do for Ya.........Good luck (with your gas guzzler...lol), and......Be Safe, take care, and have a good one.
Hey Rocky, thanks for the quick response. Sorry, my mistake not paying attention on the 350 Ford. After reading what you sent back on the 350 I should've wrote 351 Modify Ford. Sorry about that and will keep you up on my resetting and see what the outcome ends up, thanks Roger.
Greetings...Rogelio Camarena...........You're welcome, and, there's no need to be sorry, at all, my friend, b-cuz, after-all, we're only talkin', a difference, of "only"..."1-cubic inch"...lol..........When you were sayin', about, a 351..."MODIFY"...Ford (engine), then, depending on, just..."what"...???...was "Modified", as far as your Engine is concerned, then, that alone, can make all the difference in the world, as to, being able to, "Pass" the Smog Test..........Here's a pretty good example for Ya..........Let's say, that, a quite "aggressive", Performance Camshaft gets installed in the engine, that, results in a rather, not so smooth idle/fires kinda intermittently, at idle speed...........Well, I'm kinda thinkin' that, the HC's/Hydrocarbons, as well as, the CO/Carbon Monoxide..."levels/readings"...would probably, end up being, "way over", the "maximum allowable"..." exhaust gas/emission level/s"...that were specified, by the smog testing establishment............If you care to, you can let me know, just which..."Modifications"...???...that were made to your engine, that way, I'll have a much better idea, as to, what you're up against, when it comes to, trying to, receive, and see, the "Pass" (word), printed on, your Smog Testing, print-out/document/paper, and.......till next time.......Be Safe, take care, and have a good one.
Greetings...yogiberra47.................You're welcome, and, thanks for the nice comment, and for watching too.............Getting an Engine, to just Run good, is one thing, but, things get really, shall we say, "Precise" (somewhat), as it applies to, just about Everything, that affects, the Amount of Pollutants, that are found, in the Exhaust Gas, that is Exiting the Vehicle's Tail Pipe/s, during, that good ole "Smog Test" (aka, Vehicle Emissions Test)..............Even, if, all of the Settings/Adjustments are good to go, that's only one part of, what will Help the Vehicle, to be able to Pass the Smog Test............All Wiring...Vacuum Hoses...Smog Gadgets/Devices...Catalytic Converter/s (if applicable)...Spark Plugs...(just to name a few), have to be in really good shape (almost like new, somewhat), and working properly, cuz, for example, all it takes, is one, very small (ignition, or fuel system related) "Misfire", and that Smog Sniffin' Machine, will be Reporting, that not so liked, "Fail" word, on the Smog Testin' Report (card...???...lol).............I think, that, I recall hearin', that, in California USA, Vehicles, that are 1975 or Older, are Smog Exempt...???...and maybe, that might mean, No Smog Testing required...???...oh, and, if so, that to me, is, as good as, avoiding a..."Migraine Headache"...!!!...especially so, if the Vehicle in question..."Fails" the "Smog Test"..."More"...than..."Once"...!!!...Yikes...!!!...lol...and.......till next time........Be Safe, take care, and have a good one.
great video I will use it to dial in my trans am quadrajet carby. it was rebuilt but seems to backfire and big down under acceleration. if I roll on slowly it revs up but any quick throttle seems to make it bog down and misfire.
+evilswingythingy Greetings evilswingythingy....Thanks for watching, and for, Your nice comment as well..............................I've rebuilt, Set-up/Dialed-in, several Quadrajet and Dualjet, Rochester Carburetors, over the years, and had some very good Performance, and some pretty decent Fuel Economy as well, if I went easy on the Gas Pedal, that is...lol.................................First thought that crossed my mind, is, for You to have a Look in Your Trans Am's, Engine Compartment, for, what is known as a V.E.C.I. Label/Sticker, and if You happen to find one, then, that my Friend, will usually have some good information printed on it, that, might be be tellin' You, things like, the Factory Recommended Procedure , to Set the Idle Mixture Screws, and the Curb Idle Speed Setting, for Your Trans Am's, Rochester 4 Barrel Carburetor, as well as, Your Distributor's, Initial/Base (Stock/Factory) Ignition Timing Setting as well, providing that Your Trans Am's Engine and Components, are rather Factory/Stock in nature, that is.............................Try this...Run Your Engine, the Day "Before", You do the Following, in order to make sure, that Your Quadrajet's "Float Bowl", has Lots of Gasoline in it, or, the following "Test", will "Lie" to You...!!!.............................Now, it's the Next/Following Day, and...having, Your Engine "Cold and Not Running", Remove, Your Engine's, Air Cleaner Housing's "Top/Lid", and, while Moving Your Carb's Throttle Lever, with One Hand, Look Down Inside, Your Carb's, Primary/Front Throttle Bores (You'll probably have to, with Your other Hand...Hold Open, the Choke Plate, in order to see this)...to make sure, that, Your "Accelerator Pump", is "Squirting 2 Strong Streams of Gasoline", cuz, "If One or Both Streams of Gasoline, are Weak or Intermittent", then, You have probably found Your Problem, "Acceleration-wise", that is, and, make sure, to Re-Install, any of the Parts and Pieces, that You Removed, Before You Start Your Engine............................Then, as for Your Carb's "Secondaries", meaning the 2, Larger, Rear Throttle Bores, that have that Air Valve Door/Plate, on the Top of them, then, here are a few things to consider..............................The Choke Pull-Off, (looks, kinda like, a little space ship...lol), in most cases, "Also Controls the Opening Rate", of Your Quadrajet's, Secondary, "Air Door", so, "if" You are still Using the "Old Choke Pull-Off", they/the Old Ones, at times, can kinda, get some-what "Stuck, or Stick", or, maybe, Move Too Slowly, making for a Secondary Air Door, that "Doesn't Open, at the Proper Rate", if at all...???...(when Malfunctioning, in the Not Opening properly sense, the Secondary Air Door/Plate, kinda Acts like the Choke Plate, Over the Primaries does, as in Way Too Rich, of an Air/Fuel Ratio), which, as I've Experienced in the past, can make, for an Engine, that sounds rather Sick, and kinda goes "pop...Pop...POP", when-ever getting on the Go Fast Pedal (aka, Gas Pedal)..............Then, there is, the "Torsional" (twisting motion)..."Wind Up Spring"...that also "Controls the Opening Rate/Amount", of that Secondary Air Door, as well...............................If Nobody messed with the Setting, it should be, oh, shall we say, In the Ball-park, setting-wise, that is...............................If You happen to have, the Rebuild Kit's, Instructions/Paper, then, Your Rochester Quadrajet's, Settings/Adjustments..."Specifications"...should be printed on it/them..............................That Secondary, Air Door, "Wind-Up Spring", can be Adjusted, if need be, and, in most cases, it only requires a Small Allen Wrench, to, both, Unlock & Lock, the Secondary, Air Door's "Torsional, Wind-Up Spring", well, once the Correct Setting is determined, that is..................................Air Filter and Fuel Filter/s Clean...???.............................Fuel Pump, Pumping as it should, as in, both, proper Pressure and Volume as well...???.....................................Ignition Timing plays a very Important Role as well, so, make sure, that, the Ignition Timing, is Correct.............................All Ignition Components, have to be in Like-New Condition, and things like Spark Plug "Gaps", have to be Verified, and Set, if need-be.............................Have You been keeping up with "Maintenance", as in, Change/Replace, any & all Parts, as recommended, by the Pontiac/Trans Am's, Owners/Service Manual, and, also, having/doing, a proper "Tune-Up" as well...???...as a well Maintained, and In-Tune Vehicle, will Perform much better, and, if You can keep the Lead (Led) out of Ur Foot, then, Fuel Economy, it will be...lol......................I have quite a few "Automotive Related Videos", on my UA-cam Channel...RockysRoadshow...and, if You care to, You can have a look at them, if You so wish...enjoy...and, if You leave a comment/question or two, I'll do what I can, to help You out...................Also, if You want to let me know, about Your Trans Am, as in Year, Engine, and any Modifications at all, then, for the most part, I can be a bit more Specific, and, a little less Generic, with the Help, that I'll be able to give you...thanks...................Well.....Till next time............Be Safe, take care, and have a good one.
+RockysRoadshow Thank you for that thorough reply. ok to start here is the vehicle info: 1980 Turbo Trans Am Indy Pace car (301 turbo engine) rochester only built this carby for one year only model#17080274 i purchased this on ebay fully rebuilt new parts and cost almost $750 i had to replace the incorrect carby which was off a 79 olds and had no connection for the pevr as well as not having the power piston control via extrrnal means. now that is all replaced and Pevr rebuilt and tested. I did a basic procedure you suggested in the video and noticed the vehicle only backfired once but apart from that it allows me to press the accelorator to the floor, but.?...its still very sluggish and i noticed after doing this procedure the idle seemed to be slightly up and down. new plugs gapped to forum reccomended size, new air filter and air hat, new fuel pump (old one was leaking into crank), full oil change and filter, new fuel filter as well. it is a dog to start and always needs to be turned over 4 to 5 times with a few pumps of pedal, and when it starts it wont let you press the accelrator or it will still. you have to sort play with tiny little presses on pedal to get it warmed up. once its warm it idles fine. i will try some of the suggestions you made to see what difference it make. i noticed the EGR valve doesnt seem to work (attached mytyvac and it wont function). timing is set to stock and all leads and plugs are firing as well.
+evilswingythingy Greetings evilswingythingy....Well, it's sure a good thing, that, You did get the "Proper, One and Only, Factory Rochester 4 Barrel Carburetor", for Your 1980...Pontiac 301 Turbo V-8, and hopefully, it was Rebuilt Properly, along with, the Correct, Factory Designated Parts (as in Part Numbers/Calibration/Sizes of Jets and Metering Rods, etc.) as well (I hope)...............................The 2 Secondary Metering Rods, in Your "Exact" Carb, from what I saw, are quite a bit "Richer", as in, will provide a much Richer Air/Fuel Ratio/Mixture, when Your "Secondaries" start coming in, to help Cool Your "Turbo Equipped" Engine...................Now for that PEVR/Power Enrichment Vacuum Regulator.............It appears that, a Turbo-Charged Engine's, Intake Manifold's, "Vacuum/Pressure", is quite a bit different, when compared to an Engine, that Doesn't have a Turbo on it, and that's pretty much Why, there is the PEVR System on Your Turbo 301.................On an Engine, that Only has a Quadrajet Carb, sitting on top of a Regular Intake Manifold, then, to Control the Power Piston (inside the Carb), that makes the Primary Metering Rods (2 in this case), go up and down, inside the 2 Primary Fuel Jets, in order to Regulate, the Air/Fuel Ratio/Mixture, there is a Spring, trying to Push the Power Piston "Up", and, if the Vacuum Signal (manifold vacuum), Under the Power Piston, is, shall we say Stronger then the Spring, and in this case, while the Vehicle is just Cruising along, not too fast, the Power Piston Stays Down (unless there happens to be a Cam, on the primary throttle shaft, where-by, the power piston, will go as low, as that Cam will let it)......................When the Manifold Vacuum Signal Drops "Below", the Opposing Spring Pressure, like when You do a Wot/Wide Open Throttle Acceleration (Pedal to the Metal), the Power Piston Rises "Up" as high as it can go..............................Primary Metering Rods "Up" = Richer Air/Fuel Ratio/Mixture, due to Smaller Diameter of Metering Rod in the Jet..........."Down" = Leaner Air/Fuel Ratio/Mixture, due to Larger Diameter of Metering Rod in the Jet.........................Now then, Your "Special Rochester Carb", has an "Extra (vacuum) Hole/Passageway", leading to Your Carb's Power Piston, and, with the help from Your PEVR (Valve), and the rest of that System, the Power Piston/Primary Metering Rods, will be able to Rise Up, to the Richer Air/Fuel Ratio/Mixture Position, otherwise, due to the, shall we say, "Messed-Up, Turbo-Charged, Engine's, Intake Manifold's, Vacuum/Pressure Signal", and Not Having the Power Enrichment System (including the PEVR...Valve) in place, or operational, the Primary Rods, during certain conditions, would stay Down, when Not Wanted, in the Lean position, and a Lean Running, Turbo-Charged Engine, while under a Load, "Is Not a good thing", and, Engine Damage, it just might be...!!!.................................Next time, You happen to have Your HEI/High Energy Ignition Distributor Cap "Off", have a look, and see, if You can see, that, the Ignition Module, has a "Total of 5 Pins" on it (2 on 1 end, and 3 on the other end of it), and hopefully, it is the Correct One..........................Then, there's supposed to be a "Control Box", that takes the Signal, from a Knock Sensor (1 or is there 2...?), if there happens to be, an Engine..."Knock"..."Ping"...or..."Rattle" (as in Detonation or Pre-ignition), and Your Engine's Distributor, should be Retarding/Taking out, about 20 Degrees (Crankshaft Degrees, or was it Distributor Degrees, as Distributor Degrees are 1/2 of Crankshaft Degrees)...???...of Ignition Timing, and, once the Knock goes away, I believe that, the Ignition Timing will Advance, back up to a point, just before that dreaded Knock takes place (I hope)............................The "Advance Weights", inside Your HEI Distributor, could be Sticking or Stuck, and, if so, that will cause any Engine to Run like (use Your Own Bad Word Here...lol)................................On Your HEI Distributor, there should be some Identifying Numbers, Stamped on the Outside, of the Largest Diameter (Aluminum), just below, where the Distributor Cap mounts..............................Make Sure, that, those Numbers "Are the Correct Ones", on Your Distributor, for Your 1980...301 Turbo Engine, just in case, as, I'm pretty sure, that, the Ignition Advance Curve (Weights & Springs), are Set-Up & Matched, for the needs of Your 301 Turbo...............................Also, make sure, that, Your Vacuum Advance Unit/Canister, is the "Exact One" that goes with Your Special HEI Distributor, as there are So Many Different Ones Made, and, Having Different Degrees of Vacuum Advance (those Vacuum Advance Degrees....were they Crankshaft Degrees or Distributor Degrees...it's Important to know...!!!), as well as, how many Inches of Mercury (Hg), that, "it," Starts (pulling) at, and Finishes (pulling) at, as well...!!!...Yikes...!!!.......................Idling Up and Down...???...could be a Vacuum Leak, or, maybe, the Idle Mixture Screws are Too Lean (too far in), or, one is in more, or out more, then the other one, perhaps, as in Un-Balanced...................Pumpin' the Gas Pedal while Cold...???..................................If Your Engine has Not been Running for a few Days, Your Rochester Carb's Float Bowl, might be on the Empty Side, as, Gasoline will somewhat Evaporate, and, just think now, the last time You Drove Ur Trans Am, how Hot the 301 Engine was, and how Hot, the Turbo and the Hot Exhaust Pipes/Tubes got, and turned Your Engine Compartment into an "Oven"...!!! (Gasoline might get Evaporated, with a Hot Metal Carburetor...don't-cha think...???...lol)..............Difficult, Cold Engine Starting...Incorrect Starting Procedure, or, could be, that Your Quadrajets "Choke" is not Set-Up properly, as in, having the Choke Plate, Close Fully, before You turn the key, and/or, the Choke Plate Doesn't Open, the required amount (vacuum kick/vacuum break), once the Engine Starts................................Also, the Fast Idle Cam & Linkages, have to be set to Specifications, and the Fast Idle Speed Screw (Fast Engine RPM's), has to be Adjusted correctly, etc............................About Your "EGR/Exhaust Gas Recirculation" Valve...Not Holding Vacuum........well, some are "Designed that way"...Say What...???...lol...Your EGR Valve, might be the "Positive Pressure Type", that Depends on Exhaust System "Back Pressure", to travel up the EGR Valves Hollow Stem/Shaft, and, when there's enough Exhaust "Back Pressure", it Activates a little Valve, up near that Big, rubber-like Diaphragm, and when that Little Valve Closes, then, and only then, will Your Not so Mighty...Mighty-Vac...become Mighty, once again...!!!...lol..........................Then, there is also, supposed to be, a "Negative Pressure EGR Valve", that, from what I recall, would be used on a High Performance Engine, where "Negative Pressure" would Activate, that Little Valve (if it works that way, that is)................................Your Pontiac 301Turbo, is quite the Engine alright.............Special Crankshaft..........Strong Engine Block..........Maybe, has a High Pressure Fuel Pump, about 10 PSI/Pounds per Square Inch Fuel Pressure (I'm use to seein', about 5 to 7 PSI)................Maybe a High Pressure Oil Pump..."60 PSI"...there-abouts as well, perhaps..............Another thing to watch out for, is, usually, the Higher the Per-Centage of Ethanol (aka, Alcohol), that's in Your Gasoline, the "Leaner Air/Fuel Ratio/Mixture", that, one of these Older Carbs, will be administering to Your Engine's Intake Manifold, and in the case of a Turbo-Charged Engine, that's Not a very good thing at all..............................I hope that, Your Trans Am's Exhaust System, isn't too Loud, so You can Listen for any...Pinging...Rattling...or...Knocking...coming from Your Engine, and if You do Hear any, Park Your Trans Am...Get it Fixed... so Your Pontiac 301 Turbo Engine...Doesn't get Damaged/Destroyed...!!!..........................Don't forget now...They Don't make Pontiacs...Any-More.................Well........Till next time.......Be Safe, take care, and have a good one.
+RockysRoadshow I Printed all the notes you created and will run through them today. So far the NEXT DAY TEST passed 2 x nice squirts of fuel in the primary. I also checked the timing and its at factory set 8 degress. Tested the distributor vaccuum advance using the old MightyVac and I worked fine as well. I will start a channel for the 301T and add all the info about it and work I am doing on it. thank you for the time you took to research my car and caby as Its as very unusual motor and layout that most mechanics know nothing about. speak soon
What setting is the Fast Idle screw set to when you started this project? You didn't mention that. Should i have it all the way snug tight by hand? the mixture screws should be 3 full turns out right?
Greetings...Cb BroWnN........Thanks for watching.........Was it the..."Fast Idle Screw"...or, the..."Curb Idle Screw"...???...b-cuz, they happen to be, two different kinds of animals, so to speak..........Fast Idle (is controlled by the fast idle screw adjustment, while it is making contact, with the fast idle cam/or lever) and, is only in use, while the engine is cold, and, while just warming up..........Curb Idle (speed), is only working, when the engine is warmed up to, about operating temperature, and, the choke (system), is fully off..........It's usually, only, the two Idle Mixture Screws, that get turned all the way in/clockwise..."Very Gently"...until, each one of them, comes to a stop (so, as to...Prevent Damage, to their tapered, needle-like tips, and the little hole that they go into)..........The two, idle mixture screws, being adjusted to, 3-Turns out (from being Gently seated to a stop), is just a rough starting point, so the engine, will at least, run ok, until it fully warms up to operating temperature, then, from that point/rough setting, the (idle speed) Air/Fuel Ratio, will usually become Leaner, as the 2 idle mixture screws are turned in (not too much/too far), in a clockwise direction (from that rough setting, being, 3 turns out, from being gently/seated to a stop)............Perhaps, watch this Video, a few more times, and see, if it helps you out at all...........So then, just let me know, if it's the "Fast Idle Speed"...or, the..."Curb (slow) Idle Speed"...(or, maybe Both...???), that you want to know more about, and.......till next time.......Be Safe, take care, and have a good one.
I have a 9128S made for the IH Scout for my 1979 Scout II with 345 V8 and 727 auto trans. I bought it supposedly rebuilt to IH OEM specs. It started up first try but was fast idling at about 2000-2500 rpms and once it warmed up it went to about 1400 rpms. So I turned out the fast idle to about 1800 and curb idle to about 750 rpms. When I drove it the first time, it dies when I give it a lot of gas. I can ease it up to speed but cannot punch it without it stumbling and dying. Do I need to go through the idle mixture screws tuning you show in this video? I'm getting an analog engine analyzer so I can know rpms exactly. Any help greatly appreciated.
Greetings...Tracy Dixon...……..Thanks for watching...…….Well, if the idle "mixture" screws, are adjusted good enough, to have your engine idling nice and smoothly, then, that, in itself should be ok, thus far...…….Here are two things, that can cause stumbling, on an aggressive/full throttle take off...…….Does the vehicle accelerate alright, when driving normally (if not, then, it'll usually be, something wrong with the accelerator pump system)………..If the normal driving acceleration is alright, then, we'll move on to the secondary's "air valve"...……..Having the engine "Cold", and "Not Running", push the "stem", that comes out of the choke pull-off (look like a little space ship), all the way in, then, release it, and watch closely, how it extends outwards, to its maximum length...……..A good choke pull-off "stem", should come out smoothly, and reasonably, straight out as well (not leaning to the side)………..This test, is a pretty good indicator, as to, the condition, of the rubber-like diaphragm, that's hiding, inside of the choke pull-off...……The choke pull-off, regulates the opening rate (time-wise), of the secondary air valve...………..There is also a torsional (wind up) spring adjustment, for the secondary air valve too...…….On one side, of the air valve's shaft (end), there will be an outer locking ring, which can be loosened, with a good fitting screw driver, and, once it is loosened off, the secondary air valve, should flop open (vertical)………..The inner screw head (isn't a real screw at all, it just connects to, one end of the torsional wind up spring)………..So then, once loosened, adjust that outer locking ring, so there is a slight drag (resistance), when using a smaller screw driver, to adjust that (smaller) inner screw head...……..Start turning the inner screw, until, the rear most side, of the air valve, comes up, and just touches the boss/stop, that is part, of the Thermoquad's, top aluminum casting...…….Once that stop point is made, then, the additional turns/partial turns, could be called, the spring wind up (amount)………….My Thermoquad, has a specification, of 1 and 1/4 (one and one quarter) turns, spring wind up...…….Maybe try 1 and 1/2 (one and one half) turns, to see if it helps or not...…….Once, the spring wind up adjustment is made, make sure to tighten the outer locking ring, or...oh oh...it will be...lol...…….Shouldn't need any more, than about, 2 turns, on that wind up spring, or something else, isn't, as it should be...…….You can also try this...…...Once the engine is fully warmed up, shut it off, and, put a cover (tin foil or plastic bag), on top of the Thermoquad, so, any potential, small flying parts, don't get inhaled by your engine...!!!...then, disconnect that metal rod, that goes from the choke pull off, to that curved/slotted bracket, that's on the air valve's shaft (end), and, remove bag, from top of Thermoquad, etc. ……...then, test drive...results...??? (better or worse...???)………..I did a modification, that eliminated that rod, from the secondary air valve, on a standard transmission car, and, Wowsers…!!!...went crazy good...!!!...but, I had to drill a small hole, in that straight arm (that's, close to, that curved/slotted bracket), and, had to make, a new/shorter link (rod), so the choke would still work (Yes-Sir-ee-Bob...that choke pull-off, has two duties/things to do, alright)………..Fuel pump ok...??? (fuel starvation, possibly)………..So then, if you are still having trouble, then, just give me a shout...…….Good luck, and...….till next time...…..Be Safe, take care, and have a good one.
Hey, this was a great video. It is something that I enjoyed working with on my vehicles. The only problem is i have not been able to find my VECI on my 77 350M Auto Ford T-Bird. The only info I'm going by is the engine valve cover info. Calling on 650 RPM on neutral, park. Question? Is this good info to go by.
Greetings...Rogelio Camarena...........Thanks for the nice comment, and for watching too.........About the only time, that, the Idle speed RPM's become important/fussy, is usually when, the vehicle has to be "smog/emissions tested", and, if the idle (speed) RPM's, are either too high, or, too low, then, that, in itself, might cause extra/not wanted smog/emissions, as well as, the testing equipment itself, might also be "Monitoring" the engine RPM's @ idle speed, to make sure that, it is with-in a certain range (possibly)............If I recall correctly, is that, the smog testing establishment, that I used to go through, might not even test a vehicle, that has an engine, that idles @ 1100 or more RPM's (that's pretty darn high...don't-cha-think?)...........You were sayin'....650 RPM in Park or Neutral (automatic transmission)...sounds reasonable to me, but, that 650 RPM, while in Park or Neutral, will probably drop down, oh, maybe about, 100 RPM's (ball-park figure), once Ya put the Brake on, and shift that auto-trans into Drive (gear), and might end up at, about 550 RPM's there-abouts, maybe (when the auto-trans, is placed in drive/brake on)...........If I happen to have an older carbureted engine, that doesn't have to be smog tested, then, here's what I usually do, to choose an Idle RPM (speed), once I have the Idle Mixture screws, adjusted reasonably well..........With a Tachometer, or, just by, what I hear & feel (so to speak), I adjust the Idle "RPM/Speed" screw, while the Automatic Transmission is in "Park" (for Safety reasons), then, with the foot Brake "On", I place the auto-transmission lever into Drive, to see, just how much the RPM's have dropped down-to.........If, it dropped too Low, then, I go back into "Park", and adjust the idle RPM's a bit higher, and then, foot brake On, and repeat as needed, until, I'm satisfied with the actual Idle Speed RPM's, while having the foot Brake "On", and, the auto-trans in "Drive".........If the Idle speed RPM's are too Low, then, the engine will probably be idling, shall we say, kinda lumpy/roughly, and not so smooth at all..........If, the Idle speed RPM's are too High, then, the vehicle will usually "Creep" (ahead, while in Drive) too much/too fast, as soon as Ya release the foot Brake...!!!...and, that's not so good, or, safe either..........Somewhere around, oh, about, 600 RPM's (give or take a bit), while the auto-trans is in Drive, with the foot brake on, and the engine is up to operating temperature/choke fully off, should be alright, for most of the older carbureted V-8 engines, that don't have to be smog tested, as I've experienced in the past..........Depending on the engine, some of them can idle, at a really low rpm's, probably more so, if the vehicle has a Standard transmission/with a Clutch, and, probably b-cuz, the engine, only has to, shall we say, "Free-Wheel", as in, no drag imposed on it, like an Auto-Trans, will be subjecting the engine to...........If you need any more help at all, just let me know, what "Exact" Carburetor (2 or 4 Barrel)...???...and, whether or not, your T-Bird, has to be Smog/Emissions Tested as well, thanks....and.....till next time.......Be Safe, take care, and have a good one.
I just bought a 1976 corvette with a 350 engine, with automatic transmission, and it has an Edelbrock carburetor installed, the person I bought it off of failed the emissions test. The HC was 3.73 and CO was 4.44, the maximum allowed for HC is 2.50 and for CO is 2.00 to pass emissions test. Could you please tell me how to adjust the Edelbrock carburetor so I can get it to pass emissions.
Greetings...Kift1991...……..Thanks for watching...…….I will mention a few things first, before I move on to, your Edelbrock carburetor, that, will probably help you out quite a bit, when it comes to, lowering your Vett's, exhaust emission level/s, which will probably, increase your chances, at passing that, good ole smog test...…….All ignition related parts, have to be in, as, good as new condition, and, adjusted to specifications.........Have a look in your engine bay/compartment, for a V.E.C.I. (Vehicle Emission Control Information) "label or sticker", and, if you find one, then, there will be, some very useful information, that will be printed on it, and it might also have, a diagram/picture or two, on it as well, possibly....……..A 1976 Corvette, would have probably had, one or two catalytic converters, as part of the exhaust system, when the Vette was brand new, and, this (Oxidizing, type of) catalytic converter, when working properly, would "lower", both, the Hc and Co, emission levels...!!!..........As I recall, General Motors (including, Chevy/Chevrolet, that made the Corvette), started to, (factory) install, catalytic converters, starting around 1975, that were known as, the "Oxidizing" type, which only, shall we say, burn-up, Hc (Hydrocarbons), and, Co (Carbon Monoxide, which is "Lethal", if a person breathed in, too much of this stuff...!!!), and, if your Vette, had, one or two catalytic converters, that were worn out, or maybe, it/or them, as the case may be, might have been, removed from the exhaust system, and, if so, then, the Hc and Co levels, will probably be, a bit higher then wanted.........Hopefully, your engine is very close, to being "factory stock", because, something like, a high performance/heavy breathing camshaft, will probably, increase the amount of Hydrocarbons, and maybe, Carbon Monoxide too (not sure)............All it takes, is, a spark plug, that "misfires", just a little bit, and that alone, will more than likely, increase the emission level/s, into, that not wanted, "fail" category...........The Initial (base) ignition timing, should be set at, the factory recommended setting, because, any "extra" ignition advance, will usually increase the emission level/s too, just so Ya know..........Now then, onto your Edelbrock carburetor..........Hopefully, your Edelbrock carb, is not too old, and worn too much, because, things tend to get, gummed-up & dirty, with age, and, lots of use...........If it were me, then, I would probably do a...100 RPM (Revolutions Per Minute)..."Lean Drop"...idle mixture screw adjustment, with the engine up to operating temperature/choke fully off, while having, the automatic transmission, set in..."Park"...with the emergency/parking brake on, while the Corvette, was on level ground, and always, have lots of "fresh air", whenever the engine is running...!!!...so the Carbon Monoxide (gas), does not Poison you...!!!.........Just watch this video of mine, until you understand, how to get the best/fastest idle speed, while keeping the RPM's at the target level (RPM's, not too high, or, it will get all messed up...!!!)...........Make sure, that, you know, what RPM's, that the engine should be idling at, while the engine is hot, while the automatic transmission is in "Drive", while you also have your foot, firmly on the Brake Pedal...!!!..........If you have a V.E.C.I. label/sticker, then, those idle "speed" RPM's, while in Drive, with the Brake on, should be printed on "it"...........If Ya don't have a V.E.C.I. Label/Sticker, then, try...600 (idle speed) RPM's...while in Drive/Brake On...engine hot..........If Ya find, that, your Corvette "creeps" ahead too fast, when you take your foot, off of the brake pedal, for your liking/personal preference, then, Ya can try lowering the RPM's, just a little bit.........If Ya can get the idle speed RPM's, that were "specified", for your "exact" Corvette and Engine, then, that, in itself, will probably be, your best bet, for increasing your chances, at passing the smog test, well, while at idle speed, that is..........Do they do a "visual" inspection, for all of the smog, parts & pieces at all...???..........Is your "NOX" (oxides of nitrogen), within, the "Pass" limit...???...if not, then, just let me know, and, I'll give Ya a few pointers, on that one as well..........Good luck, with getting your Vette, to pass the smog test, and.......till next time.......Be Safe, take care, and have a good one.
I have a 79 Lincoln Mark V two-barrel 400 and I can get to one of the adjusting screws on the right hand side of facing the carburetor what instrument do I need to get to that one I can only adjust it from one side but I can't adjust it from the other my hands don't fit and I can't see how I can get an instrument in there
Greetings...Bohemia Lite...........Thanks for watching...........I hear Ya alright (as, I use to have, and also worked on, a 1972 Ford 351 Cleveland V-8, with a Model 2100...2-Barrel carburetor on it, which is probably, very close lookin', to your, probably being, a Model 2150...2-Barrel carburetor, as far as, I might know)...........It's not so much, the Carburetor's fault, that you seem to be having, some, shall we say, "restricted access", to one, (or, in some cases, both) Idle mixture screws, and is usually, because of, all of the other parts & pieces, that might be Mounted..."right-in-front"...of the Carburetor (correct...???)...........Here are a few ways, that you'll probably be able, to get at, that, not so easy, to get at & adjust, idle mixture screw............There use to be, a, shall we say, "special", idle mixture screw, adjusting tool, that kinda looked like, a fairly long, small diameter "spring", that had, a screw driver-like handle, on one end of it, and, on the other end (of that long spring), had the proper, type & shape of "tip" (or, call it a "bit"), that would match-up, with the idle mixture screw's head (as in, a slot, for a plain tip screwdriver, to fit into, as an example), that needed to be turned/adjusted............You can also, buy or make, a fairly long, small diameter, and, long enough screwdriver, to reach in there, providing that, it's able to make it in there, in a straight line, or, can be a bit off to the side, as well, seeing as how, an idle mixture screw, usually doesn't take much force at all, to make it turn...........Might even use, a long enough, piece of plastic tubing (fish aquarium pump's, neoprene/clear tubing), that fits snugly, over the idle mixture screw's "head", as, it can bend quite easily, and might be able to, get around, something, that is slightly in the way, possibly...........Be very "gentle", when-ever turning, an idle mixture screw, all the way in, until it stops, b-cuz, it will usually have, a fairly long, quite small (in size), pointed "taper" (angle), on the end of it, so it doesn't get...Damaged...!!!...........No-matter, what "tool", you might use, to make the adjustment on the Carburetor..."Make Sure"...!!!...that your hands, and arms..."Don't come in Contact"...with any..."Spinning, or Hot engine Parts"...so you don't get hurt...!!!..........Good luck, and.......till next time.......Be (extra) Safe, take care, and have a good one.
Greetings...curtis sanchez...........Thanks for watching..........That 3 turns out (counter-clockwise), from just being lightly seated (as in, being fully closed and turned clockwise), is basically, just a rough setting, so that, the engine will start up and run alright, until the, shall we say, "fine adjustments" are made, when the engine becomes fully warmed up, to operating temperature (and also, with the choke plate, being fully open as well).........Whether it happens to be, the "rough" setting, for either, the "idle mixture screw"...or...the "idle speed screw", then, these so called rough settings, are usually called, "bench settings" (as in, on the work bench)...........Each engine and carburetor combination, will usually have its own "specification", as it applies to, the "curb" idle speed (curb idle speed, kinda means, the curb, at the side of the street, basically, and, the vehicle not moving at all, just as it would be, "idling", at a red light or stop sign)..........The adjustments are really fussy, if the vehicle has to be smog/emissions tested, and, not so much, if the vehicle "does not" have to be smog tested..........Have a look in your engine compartment, or, under the hood, for a sticker or label, that might have the (curb) idle "speed" specification, printed on it, and there might even be, the way in which to do it, as in, procedure..........Sometimes, there might be some vacuum hoses, that might have to be removed and plugged, and/or, wiring disconnected possibly...........Here are some settings, that I've used in the past..........For an automatic transmission car, the idle speed, was about 700 RPM's in Park, and would drop down to, a curb idle speed, of about, 600 RPM's, when the automatic transmission was placed in Drive, while the brake pedal was pushed down, and also, while the engine was fully warmed up to operating temperature (choke, fully off)..........The curb idle speed, can't be set too fast (RPM's, too high), for an automatic transmission vehicle, or, the vehicle, will tend to "creep" along (forward), way too fast, as soon as you release the brake pedal...!!! (same thing happens, if the choke hasn't reduced, the fast idle speed enough, while placing the automatic transmission in Drive...!!!)...........I have also seen, a "standard transmission" (with a clutch pedal) car, that had a curb idle speed, of 850 RPM's, while the standard transmission was in neutral, or, while having the clutch pedal depressed, and, engine fully warmed up, which was that high, for smog reasons...........Never, stand in front of, an automatic transmission vehicle, while it is in Drive, or, any other gear, because, you, or someone else, might get run over...!!!..........I usually, set the Idle speed screw, with the "emergency brake on", vehicle on level ground, while in "Park", at about, 100 RPM's higher than, the idle speed, that I want to have, when the automatic transmission is in Drive, while I also have the brake pedal pressed down, for "Safety" reasons...!!! (oh, and, engine fully warmed up, as well)..........If the vehicle needs to be smog tested, then, you'll have to find the specified (curb) idle speed, and set it to that...........Sometimes, there might be, what is called, a "lean drop" specification, for setting the idle mixture screws, that might be printed, on that label or sticker, that I had mentioned earlier..........The instructions (sheet of paper), that is usually found, in a carburetor rebuild kit, will usually have, quite a few specifications on it, as well as, the way to do the adjustments or settings............A Haynes aftermarket manual, will also, help a lot, with plenty of information too............If Ya need any more help at all, then, just let me know, about, your vehicle's...year...make...model...engine size and number of cylinders, automatic or standard transmission, and also, if the vehicle has to be "smog tested", or not...???............Good luck, and.......till next time.......Be Safe, take care, and have a good one.
richard collis Greetings richard collis....Thanks for watching, and, for Your questions as well...............................If, and I say If, the Vehicle in question's..."Engine"...is not subjected to, and required to "Pass", something like a "Smog/Emissions Test", and is, something along the lines of, that, of being something like...oh, let's say, using an Early 1960's...Chevy...Dodge...or Ford...Car or Truck, for Example, and also, being as "Basic" as can be, pretty much meaning, having a Carburetor, sitting on top of the intake manifold, and, not having much, in that way of "Smog Controls/Gadgets", and, "No-Computer-what-so-ever", then, as I see it, the Odds are very good, that, a Person can use, either, a..."Vacuum Gauge"...or, a..."Tachometer"...to..."Set"...the..."Idle Mixture"...and, the..."(Curb) Idle Speed", well, on a good day, that is.......................The way, that I would probably, shall we say "Set-Up", the "Idle Mixture" and "(Curb) Idle Speed" (the Engine's "Curb Idle Speed" in "RPM's", is pretty much, just that, and, as I see it, just means, what the Engine's "Idle Speed", happens to be "Set-At", while the Vehicle's Engine, is Fully Warmed-Up, and, the Vehicle, is just "Idling" near the "Curb", and Not Moving at all)..............................The "First Thing", that has to be "Determined", is, the Engine's "Curb Idle Speed" ("Automatic Transmission" equipped Vehicles, are usually Specified in "Drive", but not always, while "Standard/Manual Transmission equipped Vehicles, with the "Clutch Pedal", are usually Specified, in "Neutral/Not in Gear"), and hopefully, the Vehicle's Manufacturer has a Specification for that..................For "Safety" reasons, I always make Carburetor Adjustments, with the Engine Running...Fully Warmed-Up...Choke Off...while the Automatic Transmission is placed in "PARK", so the Vehicle "Does Not Decide to Take-Off/Move"...!!!...along with having the...Vehicle on Level Ground...Parking/Emergency Brake On...Wheel/Tire Chalks (lumber/bricks), and, have a Fire Extinguisher, with-in easy reach, just in case, oh, and, also, have the Vehicle "Outside", or, if, the Vehicle, is in a Garage, have All of the Garage Doors, that lead to the Outside/Fresh Air, "Open", as, Engine Exhaust Fumes are "Deadly"...!!!........................Here is an "Example Only", and I'm only using this example, to help People out, and hopefully, help those very same People, some-what, in, understanding, what is usually goin-on, when-ever I happen to be making a "Basic", Low Compression, Older, Factory Stock Engine's, "Idle Mixture and Curb Idle Speed", Carburetor "Adjustments"...................Once the Engine is "Fully Warmed Up to Operating Temperature"...and, the..."Choke is Fully Off"...as well, and, oh, let's say, that, the Vehicle happens to have an "Automatic Transmission", and the Hypothetical/Imaginary, "Curb Idle Speed" needs to be, for Example (only!), set at "650 RPM's (Crankshaft Revolutions Per Minute), while the Automatic Transmission is in "DRIVE" (please note, when-ever the Automatic Transmission is placed in "DRIVE", have Your Foot on the Brake Pedal...!!!)...but, like I was sayin', I make the Carburetor "Idle Mixture & Curb Idle Speed Adjustments", while the Automatic Transmission is in "PARK" (for "Safety" reasons)...then, once I'm satisfied, with the "Idle Mixture Settings", that I've made, my "Curb Idle Speed/Screw", is "Set", while the Automatic Transmission is in "PARK" (always remember Safety...!!!), to about "100 RPM's Over", that "In DRIVE, Curb Idle Speed", of "650 RPM's" while the Auto-Trans is in "PARK", meaning that, while in "PARK", I Set the "(Curb) Idle Speed Screw or Solenoid", as the case may be, to "750 RPM's" (650 RPM's + 100 RPM's = 750 RPM's), then, once the Auto-Trans is placed in "DRIVE", and, having a "Foot on the Brake Pedal", the Engine "RPM's" will usually "Drop", about "100 RPM's", give or take some "RPM's", and, if it's more or less then, that "650 RPM's (in "DRIVE"), then, in order, for me, to have that (Imaginary) Engine, end up with, a "(Curb) Idle Speed", of "650 RPM's in DRIVE", I place the Auto-Trans Back in "PARK", and Adjust the Engine RPM"s "Up or Down", with the "(Curb) Idle Speed Screw" (or Solenoid?), as required, and, it might take a few tries, to get it just right, but, as I see it, it really..."Is a Safe Way to Do it"...!!!..............................Yeah, I know, I know, what about actually "Setting the Carburetor's"..."Idle Mixture Adjustment Screws"...???...lol..............Well, it kinda worked out, the way that it did, more or less, so there would be a some-what Basic Understanding, at, oh, I guess I could say, to maybe, just get, the "Whole Picture", and to more or less, see what we are up against, that's all...............................Now then, about using a "Vacuum Gauge"...or, a..."Tachometer" (that measures the Engine's Crankshaft RPM's), and...by Using Either "Method" (Vacuum Gauge, or a Tachometer), as I see it, the "End Result", should be, about the same.........................I'll use that "750 RPM's" (in PARK), for this Example, on, something like a very Basic, Older, Rochester 2 or 4 barrel Carburetor................It's really, just a matter, of, getting "Both Idle Mixture Screws"..."Set"...at the...some-what, "Leanest, acceptable, Air/Fuel Ratio"...having the Engine, "Idling in PARK", (Smoothly), at that "750 RPM's" (in PARK)...(Example Only!)...while also, seeing the "Highest Vacuum Reading", showing on the "Vacuum Gauge", and also, having, "Both Idle Mixture Screws", "Turned Out", from being lightly seated in the Carburetor, about the "Same Amount", of "Turns, and Partial Turns", as in, having a, shall we say, reasonably, "Balanced" Adjustment, between, the 2 Idle Mixture Screws (like I was explaining in this UA-cam Video of mine, and using some chalk, on the Idle Mixture Screws, as I was showing) and, there can be the odd time, where-by, having, the "2 Idle Mixture Screws"..."Not Set Reasonably the Same", as in, Turns & Partial Turns out, from being lightly seated, that is...has been know to, have a Carburetor, that Runs, not so good, and maybe even cause the Engine to, some-what have, a, shall we say, "Hesitating Personality", perhaps...........................Same thing, pretty much happens, if using a "Tachometer", and not a "Vacuum Gauge", as well, only, the Tachometer would be showing, the "Changes in, Engine, Crankshaft RPM's", while the "Vacuum Gauge", would be showing/reading, the Engine's "Vacuum Level" (usually taken Below the base of the carburetor, and, inside the Intake Manifold)...expressed in..."Hg, or Inches of Mercury".....................................................................The Word "Vacuum", as it applies to these Gasoline Engines, can be confusing, and, the way that I like to look at the word Engine "Vacuum", is, I, just think of, the words..."Pressure Differential"...or..."Differences in Pressure", as in, the..."Difference in Pressure"..."Between"...the..."Air/Atmosphere, just Outside the Carburetor/Air Filter Housing...and the..."Air Pressure/Vacuum"...that is..."Just Below the Carburetor's Base, and Inside the Intake Manifold"......................Funny thing though, I've always thought of, Buying a "Vacuum Gauge", after all of these Years, and, I "Still Don't have One"...!!!...Say What"...???...lol...Yes-Sir-ee-Bob, all, I've ever used, is, one of my Trusty ole "Automotive Specific Tachometer Equipped Multi-Meters", and, had some pretty good luck (might even be, some skill, somewhere in there, as well...???...lol), in, being able to make the required Carburetor Adjustments, to get those damn Vehicles, through, the "Smog Test"...and maybe..."Even Pass"...!!! (well, at least most of the time, that is...lol)..............................Basically, just using a "Vacuum Gauge", to "Set" the Carburetor's "Idle Mixture", with the "Idle Mixture Screws", would, pretty much, be Done the "Same-Way", as I've done in this particular UA-cam Video of mine, but, with a few Exceptions.............................Instead of, Adjusting the "Idle Mixture Screws", to get the "Highest RPM's" (that's "Just Before", I proceeded to do, the "Lean Drop/Method", that is), using a "Tachometer", like I've done, in this Video, then, if a person, were to Use a "Vacuum Gauge", then, just aim for, the "Highest Hg/Inches of Mercury", while Adjusting the, 2 Idle Mixture Screws, about the same Turns/Partial Turns, Out, from being lightly seated (always, try to remember the word "Balance" while making Adjustments, to Both/or Either, Idle Mixture Screws), while, also, keeping the Engine "RPM's at the Specified (or chosen) "RPM's".........................If using a "Vacuum Gauge", just follow this Video of mine, up to the "Point"..."Just Before"...I start "Doing the Lean Drop, in RPM's", with the "Tachometer", but, "Instead", this time, Using a "Vacuum Gauge", to get the "Highest Hg/Inches of Mercury", showing on the "Vacuum Gauge", at the Specified/or Chosen RPM's, as that's essentially, what to do, but only "if", the Vehicle in question, Does Not have to be Smog/Emissions Tested"...!!! (just so, You and Others are aware, just in case...???)...............................Try to find, what is known, as a "V.E,C.I." Label or Sticker, that might, just be Stuck, inside Your Vehicle's Engine Compartment, somewhere, as that, my Friend, will usually, have some very Important and beneficial "Information" on it, that, pertains to, and in some, if not most cases, might just have, the Idle Mixture & Curb Idle Speed, "Specifications", and/or, "Setting Procedure/s" on it, as well, hopefully...........................Another Option, that should be available, and, to be even more Accurate, as to the Final Carburetor Adjustments, can be done, by a Vehicle "Fix-Em-Up-Establishment" (aka, car or truck Repair Shop), for a Fee/Charge, that has a "Tail Pipe Probe", that is connected to a Hc/Co (Hydrocarbon/Carbon Monoxide) Meter, where, the Technician/Mechanic, will be able to "Fine/Tune Adjust" the Carburetor, "Based on the Exhaust Emissions", coming out, of the Vehicle's Tail Pipe/s................................I hope, all of what, You have read here, helps You out some-what, and...Till next time............Be Safe, take care, and have a good one.
Thanks for taking the time to make this video. I have a 2 barrel Autolite 2100 carb and an automatic. Do I need to plug the vacuum advanced like if I was checking timing or leave vacuum advanced intact? Also with the automatic, you do recommend adjusting while car is in drive or can this be done in park?
Greetings Quang Bui....You are welcome, and thanks for Your comment/questions....I have spent quite a bit of time, working on a Motorcraft 2100 Carburetor, and, I'm pretty sure that it's the same as the Autolite 2100, with both of them being 2 Barrel carburetors....I have no idea, as to which Vehicle and Engine that Your 2100 2 Barrel Carburetor is mounted on...and...Do You have to have Your Vehicle "Smog" (aka, Emissions) Tested?...if so, then, You have to be a bit more "Precise" in Your Idle Mixture and Idle Speed Screw/s "Settings!" If Your Engine is Stock, without any Modifications, then, the best thing to do, is to have a look around Your Vehicles Engine Compartment (under the Hood), and see if You can find a V.E.C.I. (Vehicle Emission Control Information) Label/Sticker, as that Label/Sticker, usually has the required Information, on how to "Set-Up/Adjust" Your Autolite 2100 Carburetor for Smog/Emission Testing. In the event, that You are unable to find the required Information, then, here is what I would usually do, to Adjust the "2" Idle Mixture Screws, and the Curb Idle Solenoid or Screw... The Engine has to be Fully warmed up, with the Choke completely Off and Open. Air Cleaner Housing, and Air Filter "Installed". Air Conditioning, Heater Blower Motor, etc. Turned "Off". I usually do a "Lean Drop" of, no more then "100 RPM's", from the Fastest Idle Speed, that I can get with the "2" Idle Mixture Screws. Some of the V.E.C.I. Label/Stickers that I have seen, can have Different Lean Drop RPM Settings, and some, might even be around 40 RPM's, depending on the Vehicle Manufacturer, Engine and Carburetor, that was Originally Installed. You just have to remember, Not to let the Engine Idle Speed get Too High, as that can cause the Mechanical and Vacuum Advance to Add "Unwanted" Ignition Timing, that usually "Alters" the Speed/RPM's of the Engine. I usually do the "2" Idle Mixture Screw Settings, while the Vehicle is in "Park" (automatic transmission), for Safety reasons. Vehicle on Level ground...Automatic Transmission in "Park"...Parking Brake On...Wheel/Tire Chalks (aka, Bricks, Lumber, etc.) to keep the vehicle from Moving! The Vacuum Advance (rubber) Hose, should be "Plugged", so as to make certain, that, the Vacuum Advance "Is Not" causing an RPM Change, due to Advancing the Ignition Timing, which will Mess-Up the Lean Drop, and Idle Speed Settings. Most Stock Ignition Systems, on the older carburetor equipped engines, as far as I know, Don't usually Start Advancing the Ignition Timing, until, the Engine RPM"s Exceed about 1000 RPM's, but, I will bet, that there are exceptions! Once the Engine is Fully Warmed Up to Operating Temperature, Set the Idle "Speed" "Solenoid or Screw" to "800 RPM's", then Adjust Both Idle Mixture Screws, a little at a time, to get the Fastest Idle Speed, showing on Your Tachometer, but, make sure that if the Engine RPM's start to go Higher then that "800 RPM"s", then Reduce the Idle Speed back to that "800 RPM's", with the Idle Speed "Solenoid or Screw", and re-adjust those "2 Idle Mixture Screws", to get the Highest RPM's, while Not going over that "800 RPM's", by very much. Once You have the Highest RPM's that You can get, with the "2 Idle Mixture Screws", Re-Adjust the Idle "Speed" Solenoid or Screw, to get Exactly "800 RPM's" showing on the Tachometer. Then, put a Chalk Mark, or other mark, on the "2 Idle Mixture Screws", at the 12-O-Clock (aka, closest to the Sky) position. Then, it's just a matter of, Turning "In" (Clockwise), the "2" Idle Mixture Screws "EQUALLY" (Same Amount for each Idle Mixture Screw), each one a little at a time, turning the Left one a bit, then the Right one a bit, and go back and forth between the 2, Until the Tachometer is showing Exactly "700 RPM's", and "Both" Chalk Marks are Pointing in, Exactly the same Direction, as in the "O-Clock" position! Once the "Lean drop" Procedure is done with the "2 Idle Mixture Screws", then just leave them "Set" at that Position! Once that is done, making sure that You can see Your Tachometer while sitting in the Driver Seat, put Your Foot on the Brake, and put the Automatic Transmission Lever in "Drive", and see what RPM's the Engine is Idling at... If the Engine "Idle Speed", while in "Drive" with Your Foot on the Brake, is either too High or too Low, then, put the Transmission, back in "Park", and Adjust the Curb Idle "Speed" Solenoid or Screw to Increase or Decrease the Engine RPM's, then, Foot on the Brake, and put the Transmission in "Drive" again, to see what the Engine RPM's are at. Repeat the "Idle Speed" Solenoid or Screw Adjustment, if needed, while the Transmission is in "Park", so the Vehicle Won't Move! (for Safety reasons!). If Your Vehicle "Does Not" have to be Smog/Emission Tested, then, You can usually, just Adjust the "2 Idle Mixture Screws" for the Fastest RPM's, "Without" having to do the "100 RPM Lean Drop" Procedure, but, Your Vehicles Gas Mileage/Kilometer-age might not be as good, especially while Your Engine is Idling at a Stop Sign or Red Light. Your Engine has to be "Tuned-Up", and the Maintenance "Items" must be up to date, to give Your Engine the Best Chance, at running the Best that it's able to. If You need any help at all, let me know, all that You can, about Your Vehicle and Engine, or, I will still, be going on a... ..."Wild Goose Chase!!!"...lol. Good Luck... Be Safe, take care, and have a good one.
RockysRoadshow Thank you for the detailed written instructions. Sorry for not entering my car's info. No, I do not need to pass smog because it's a 1969 Mustang 302 (probably orig). In California I believe any car older than 1975 do not need to be smogged. Air cleaner, fuel filter, plugs, plug wires, oil, electronic ignition have been recently changed. Carb have been replaced/rebuilt a few times since I've owned it for less than a year due to numerous issues but seems to be running well now except for fumes. The reason I want to apply you method is when I have the windows rolled down or the top down and stop at a stop sign/light, seems like there's a back draft and the gas smell would rush pass the car. Thank you again for passing along your wealth of knowledge to myself and others!
Quang Bui Greetings Quang Bui....Exhaust "Fumes" You say?...Been there, Seen that...and..."Fixed" that too...!!!...lol....Before I start tellin' You, about the Many Things, that can cause, what appears to be a "Rich" Air/Fuel Ratio, that Your Autolite 2100 Carburetor just might be Feeding Your Engine, I will mention the following....The Gasoline that is being sold these days, usually has a certain "%-age" (aka, Percentage) of "Ethanol" (aka, Alcohol) added to the Gasoline....This Percentage of Ethanol in the Gasoline can vary somewhat, depending on where You live....The Higher the Percentage (or amount) of Ethanol in the Gasoline, the "Leaner" the Air/Fuel Ratio, the Carburetor will be administering (aka, Feeding) Your Engine. The more Ethanol that is in the Gasoline, the More that problems will usually occur, not only causing a "Lean" running Carburetor/Engine, but this Ethanol, as I have been reading, can cause Fuel System Parts, including the Carburetor itself, to start to Corrode, and cause deterioration of rubber-like parts as well. When You (or someone else) Rebuilt Your 2100 Carburetor, did You (or they) Install a "New" Float? If it's made of "Brass", which I highly doubt, then the Float is usually made out of a Material called "Nitrophyl" (looks like black plastic), and this stuff, is prone to acting like a "Sponge", and some of them, over a period of time, can, and will "Absorb" Gasoline, causing the Float to start to "Sinking" somewhat. When these Nitrophyl Floats start Sinking, the "Wet" Fuel Level in the Carburetor Float Bowl will usually become "Higher" then wanted in the Float Bowl, and will usually cause an Overly "Rich" (Air/Fuel) Ratio, and, could be the cause, of all of those excessive Exhaust "Fumes" that You had mentioned. Some People, Install a Float, be it New or Used "Without" Checking and Setting it Properly, to the Proper "Specification", which, as I see it, will make for a "Not-So-Fun" (and Poorly) Running Carburetor! (could cause a too "Lean" or too "Rich" Air/Fuel Ratio). (Please, don't use the following, as these Measurements, only Applied to one of the Motorcraft 2100 Carburetors that I rebuilt a while back...."Dry" Float Setting was 3/8" from the Top of the Float Bowl, to the Top of the Float, while applying light pressure to the Needle/Seat assembly, and, the "Wet" Fuel Level in the Float Bowl was 3/4", as I recall). Make sure, that Your, I hope "New" Float, is "Set" to the Proper "Specification", that You can find, in a Factory Service Manual, or, on the Rebuild Kit's "Instruction Sheet/Paper", for Your Exact Vehicle and Engine. Make sure, that Your 2100's Choke, as in, the Fast Idle Cam/Screw, Linkage, and that the Choke Plate is Fully Vertical (aka, Fully Open), when Your Engine is Fully warmed-up to Operating Temperature, or, it may cause..."Fume-City!"...lol. Sometimes (I'm thinkin'), if Your Engine may have "Back-Fired" at some point in time, that has been known, to sometimes "Rupture" the "Power Valve" Diaphragm! (some call it an Economy Valve), which, as I recall, makes for a "Very Very Rich" (Air/Fuel Ratio), and, if that be the case, that could very well be, what's causing those "Fumes" that You are experiencing. The Power Valve is Located "Underneath" the carburetor Float Bowl (if memory serves me right, that is). Also, if someone "Messed-up", and put the "Wrong" Rating of Power Valve, in the Rebuild Kit, or, if Your Engine has an Aggressive Aftermarket Performance Camshaft installed in it, that can cause a very "Low Vacuum Signal", while having the "Stock" Rated Power valve Installed in the 2100 Carburetor, that "Stock" Power Valve will usually be Adding In Fuel, when it's Not Supposed to...!!! It could be, that, Your Fuel Pump, is putting out, Too Much Fuel Pressure, which will usually "Over-Power" the Floats "Ability" to Close the Needle/Seat Assembly, which in turn, will cause a "Too High" Wet Fuel Level, in Your 2100's Float Bowl, and again I say...Fume-City!...lol. Could even be Dirt/Crud that has lodged in between Your Needle and Seat, which in turn, will cause that very unwanted Too "High" of a "Wet" Fuel Level in Your 2100's Float Bowl. Seeing as how you are so very Fortunate, as in...Not Having to have Your Vehicle Smog/Emission Tested, You Don't have to bother with that "Lean Drop" Idle Mixture Screw Setting. Just, set the "2" Idle Mixture Screws to the "Fastest RPM's", and, the rest of the Information that You should need, is already in my Previous Comment/Reply to You. Did You "Gap" Your Spark Plugs, before You Installed them, in Your Engine??? Electronic Ignition, You say??? I'm thinkin', that Your Engine's "Ignition" has been "Upgraded"... As far as I recall, a 1969 Ford, had a "Points and Condenser" Type of Distributor installed by the Factory. The Only way, that I can get close enough, to figuring out, what Your "Fume" Problem is, is to let me Know, "Any and All" Modifications or Upgrades, that are Over and Above, that of the "Factory Installed" Parts, and, if there are "Any" Running/Performance Issues as well. So then, perhaps "Check" all of the Things, that I have mentioned above, and if You like, let me know, how You're makin' out. Be Safe, take care, and have a good one.
RockysRoadshow Wow! Thanks again to take the time out to write a thorough response! Truly appreciate your time. I've done a few things with the Mustang since I've owned it. Purchased a rebuilt carb, had my original carb rebuilt, then rebuilt both myself after that. I had one that had a brass float and one that had the new nytrophyl. Not sure which one is in my car right now. When I rebuilt both carbs, I did not do anything with the choke since they were already rebuilt and new. I did replace the rest of the items that were in the kits; seats, needles, check balls, gaskets, power valves, clean the lines,... I did check the floats according to the kits with the supplied ruler. I also replaced the fuel filter with motorcraft filter, added a second filter before the mechanical fuel pump, replaced all rubber hoses with EFI hoses, replaced the fuel tank. I adjusted the choke so that when you first step on the gas pedal before starting, the plate almost closes and then open fully when warmed up. Then when I step on the gas, the fast idle disengage and curb idle takes over. Also replaced the electric choke with hot air choke since the electric choke opened the plate too quickly by using a choke stove. Seems to take a little longer to fully open which is what I was looking for. Yes, ethanol in the gas is the only thing I can buy here. There's only a few places in Southern California that sells ethanol free gas and it's at least 50 miles away. The way my car sucks up gas, it'll cost me half a tank to go fill a tank. As far as my engine is concerned, I don't have any info on it other than it's a 302. Don't know if it was ever rebuilt or any modifications were made to it. The person I bought it from inherited from his dad when he passed away so he didn't know the history. I installed the Pertronix Ignitor I so I don't have to deal with points/condensers. Seems to be OK so far. Will try to find some time to apply your techniques when I have a chance. Traveling and then planning to upgrade my front suspensions over the 4th weekend. These old cars can sure suck up you money fast but they are fun to drive. Thanks again RockysRoadshow!
Quang Bui Greetings Quang Bui....Your Engine's Spark Plugs will usually be a pretty good "Indicator", as it applies to, how "Rich" or how "Lean" of an "Air/Fuel Ratio" that Your 2100 Carburetor is Feeding Your Engine....A good place to get started, would be the following... With Your Engine "Cold", Remove "1" Spark Plug at a time, so You don't run the Risk of placing the spark plug "Wires" on the "Wrong" Spark Plugs!....I have a...How to Read Spark Plugs...Video, on my UA-cam Channel...RockysRoadshow...enjoy. Also, have a look-see at the other Videos that I have Uploaded, as I'm pretty sure, that there should be some Information, that might just help You out, somewhat. If You do, Remove Your Engines Spark Plugs, "Record" (aka, write down on paper), everything that You notice, about...Color...Deposits...Carbon build-up...and how much the "Wear Amount" (aka, Gap) is, on both, the Inner Electrode, and the Outer Electrode, and also, make sure that You Record "Which Cylinder", that "Each" Spark Plug, came out of...!!! Also, "Check" (as in Measure) the Spark Plug "Gap". If You care to, let me know, what You have Observed/Found-Out, as, those good ole Spark Plugs, really "Do" have a "Story" to tell...!!! Be Safe, take care, and have a good one.
Thank for the great vidio presentation. I have a 59 cad with 4GS carb. There is big screw with the spring in the back of the carb facing towards the driverside. I beleive it calls, Idle speed bypass screw. How do i adjust that in relation with idel mixture screws and the curbe ide screw? When I crank the screw in, the rpm drops, and by unscrewing it, the rpm goes up. Thanks for any advise.
59cadfins Greetings 59cadfins....You are welcome, and, thanks for Your comment/question, and for watching as well...................................................Before I get on with, what, information, that I will leave in this comment/reply to You, is, in order for me, to be able to help You out, to the best of my ability, would be, for You, to have a "Look", at the "Carburetor", that is "Installed"...on Top of Your Engine's Intake Manifold......................................................Please, let me know, the following.............The "Carburetors" (brand) Name (if one is showing)..."Any Numbers or Letters", that might be "Stamped" in/on, Your Carburetors "Exterior/Outside" (as in, Top...Front...Back...Left and Right Sides, and with the engine cold, and not running, You might have to use a Mirror, and a Flashlight, to See those Numbers/Letters, especially, if there happens to be any, on the Rear/Back of Your Carburetor...also, when using a Mirror, the Numbers/Letters might "Appear Backwards"...just sayin'), and also, if the Carburetor, to the best of Your knowledge, "Is" the "Original, Factory Installed" Carburetor, or, if it happens to be, something, other, then the "Original" Carburetor, as that my Friend, will help me a great deal, and also, make it, that much less, of a..."Wild Goose Chase"...that I might have to go on, as well.........................................................I had a look-see, at some pictures and information, pertaining to the Carburetor, that You were telling me about.........................................................I wasn't seeing much, in the way, of a..."4GS" Carb, as I was mostly seeing, a...."4GC" Carb, when I did the search on it............................................................Also, for the "1959 Year Model" of Your "Cad" (I remember, hearing them, being called "Caddy's...that be that), the Engine that came up in my search, was showing a..."390 Cubic Inch" (V-8)...is that Engine, the "One", that is Installed in Your "59", or, does there happen to be, a "Different" Engine in Your "59" these days...???..........................................................I didn't see, the "Big Screw, with the Spring" on it, Located, on the..."Rear of the Carb, facing the Driver's side"...but, what I was seeing, was a..."Big Brass-colored Screw, with a Spring"...Located..."Between"...the..."2 Idle Mixture Screws"...on the..."Front of the Carb".........................................................In some applications, there might..."Not Have Been"...what is commonly know, as a..."Curb Idle"...Adjustment Screw...for Adjusting the..."(Curb) Idle Speed"...of the Engine.............................................From what I saw, and kinda figured out, has me thinkin', that, that, shall we say..."Idle Air Bypass Adjustment Screw"...was being used, to..."Control the (Curb) Idle Speed", of the Engine, seeing as how, some of those Carburetors, back then, might..."Not Have Had"...a..."Curb Idle, Adjusting Screw"...Engineered/Manufactured/Installed...on them...!!!............................................................Perhaps, You can have a Look, for the..."Curb Idle Speed Adjusting Screw"...and here's what to be looking for......................................................."If", You happen to see an Adjustment Screw of sorts, that might be "Making Contact" with, what is commonly known as a "Fast Idle Cam" (that "Cam", is what "Raises" the Engine's Idle Speed, and positions the Choke Plate, when the Engine is Cold, to prevent it from stalling), then..."That's Not It"...unless, the Engineers/Designers, just might have had, that..."Single Adjustment Screw"..."Serving 2 Purposes"...at the..."Very Same Time"...!!! (aka, doing double duty, in the from of, both, the Fast Idle, and the Curb Idle as well, maybe?)..........................................The most common looking..."Curb Idle Speed, Adjustment Screw"...basically, just makes..."Contact With"...the..."Lever or Bracket"...that the..."Throttle/Gas Pedal"..."Rod" (or Cable?)...Actuates, that Controls, the, Throttle Plate/s (butterflies/throttle valves), Angle/Opening, depending on, just, how much Your Foot is Pressing on the Gas Pedal...........................................................................The Carburetor, that I was seeing in the search results, to me, looked, for the most part, just like a..."Carter AFB" (AFB = Aluminum Four Barrel, I think?) Carburetor, but, that was just a few Pictures, and I haven't a Clue, as to, "What", the Carburetor that You have there, actually Looks-Like...???........................................................."IF"...???...You Don't happen to "Find", a "Curb Idle Speed", Adjusting Screw, on Your Carburetor, then, it is quite possible, that, that "Big Screw, with the Spring", is perhaps, what the "Engineers/Designers", of Your particular Carburetor, probably used, to..."Control/Adjust"...the Engine's..."Curb Idle Speed"...especially, considering, the absence of, the, as I've mostly seen, and adjusted many times, the..."Curb Idle Speed Screw" (and in some cases, it was an electrical Solenoid), on, the Carburetors, that I've...Rebuilt/Set-up/Calibrated, and Adjusted........................................................."If", and I say, "IF", it turns out, that You end up, having to, actually "Use", that there..."Big Screw, with the Spring on it"...to...."Control"...the..."Speed"...at which Your Engine..."Idles" at, You "Should/Must", find out, what, Your Engine's..."(Curb) Idle Speed"..."Specifications" are, so, You have a much better chance, at getting it Right, the First time, hopefully.......................................................What I'm visualizing, is, it really boils down to a, shall we say..."Balancing Act"...where-as, the...(I'm thinkin')...."2 Idle Mixture Screws"...have to be..."Balanced", with the...shall we call it, an..."Idle Air Bypass Screw"...Adjustment Amount (aka, the Turns/Partial Turns Out, from being Lightly seated) perhaps, in order to have, a Carburetor (Yours, in this case), Idle Smoothly, and at the Specified (Curb) Idle Speed, as well as, having the..."Idle Mixture Screws"...Adjusted, as..."Lean" (air/fuel ratio-wise) as possible, but, "Not-so-Lean", that, the Engine, starts experiencing, what is known as, a..."Lean Miss-Fire", that by the way, from my previous experience, at times..."Can't be Detected"...Without, having a..."Smog/Emissions Test"...done, unless, the Engine, actually, starts..."Shaking"..to some extent, at (Curb) Idle Speed, that is..........................................................Before I go any further, with, how I would go about, making the Adjustment/Adjustments, with this particular..."Carburetor"...please, let me know, all that You are able to, about Your Engine and Carburetor, as, the More, that I actually Know, about, what I'm dealing with, the More, that I should be able, to help You out..................................................I sure like, what the "Designers", did back then, with those Car..."Tail-Fins"......kinda has me thinkin', that..."Airplanes and Jet Aircraft"...had..."A Lot to do with it"...!!!.....................................................Till next time.............Be Safe, take care, and have a good one.
RockysRoadshow Thank you for taking the time to respond to my question.I beleive this is the original carb on a 390 engine. The only ID I could find says, Rochester 4GS and 4jet. There is a curb idle speed adjusting screw where the throutle linkage is connected on the Dr. side. However, there is none for fast idle adjustment which is normally located under the choke on the passenger side. Or I might be wrong. The curb speed adjusting screw could be for fast idle cam adjustment and the big screw in the back could be for curb idle speed adjustement. I will try to send some pictures. I have never done sent pics before hopefully, I will figure it out.Let me tell how this started, the problem is the car would not start i had to use starting fluid so I knew the plunger was not working. Other than that the car was running perfect. So I removed the carb to get remanufactured. Once it was reinstalled the plunger was working fine the car starts up immediately. However, when i am stopped, when I accelerates the car hesitates. My research shows this is the accelerate pump issue. I know it has been replaced since it starts now. Is it lean or rich thats what I am trying to figure out. Thanks again
+Rick Smith....Greetings....Rick Smith....Thanks for watching.................You were sayin', about, Your Rochester Quadrajet 4-Barrel Carburetor..."Will Not Hold RPM's" (might not be the Carburetor...maybe...???)..................In order for me to narrow-down, what might be causing Your Engine's, lack of RPM's, then, if You can tell me, under what Engine Operating Conditions, does Your "Too Low RPM's" occur at, as in, is the...Engine...Cold...Hot...at Idle Speed...in Gear...in Park (automatic transmission)...at Cruising Speed...or what-ever it might be...???..................Also...the Vehicle's...Year...Make...Model...Engine Size/Liters/Cubic Inches...Automatic or Standard Transmission/with the clutch pedal...etc.........So then, please, Describe to me, the best that You're able to, about any Engine "Running Problems", that You are hoping to Fix, and..........till next time.........Be Safe, take care, and have a good one.
Karamelia Mitchell Greetings Karamelia Mitchell....Thanks for watching, and for Your comment/question as well............................Well...if I were to show show You, and Others as well, about how to Adjust the "Idle Mixture Screws"...and...the..."Idle Speed Screw"...on that..."1964-1966-Rochester 2 Barrel Carburetor"...that You had mentioned, then, what You would probably be Seeing, is, pretty much, like, what You, (and Others), have already Seen, in this very UA-cam Video of mine, with the exception, of the "2 Extra Secondary Barrels", that You saw, on this "Carter Thermoquad 4 Barrel Carburetor", that is.............................Generally speaking, on most "2 or 4-Barrel Rochester Carburetors, that I've Worked-On, the "Idle Mixture Screws"...are part of, the..."Primary, or Front"...Throttle Bores, and the Throttle Plates/Butterflies, that reside in "Them"..."Only"...and when "Adjusted"..."Only Affect...the..."Primary/Front Throttle Bores"...because of that particular "Idle Circuit Design" (the Secondary Throttle Plates/Butterflies, are usually Closed, on the Rochester "Quadrajet" 4 Barrel Carburetor, at Idle Speed).....................................Most, shall we say..."Old School"..."North American"..."Rochester 2-Barrel and 4 Barrel Carburetors" (well, depending on, just "What Year" we are talkin' about, some, go/went by the Name/Description, of...the Rochester "DualJet" 2-Barrel Carburetor...and the Rochester "Quadrajet" 4-Barrel Carburetor)...and, quite a few "Other Carburetor Manufacturers", that have a "Similar Looking Design", and having either..."2-Barrels" or "4-Barrels"...along with..."2 Idle Mixture Screws" as well, will, as I see it..."Pretty Much be Adjusted the Same"...but, and I say But...there are "Exceptions"...!!! (almost like Everything in Life...!!!...lol).............................What I'm getting at here, is...Does the Vehicle, and Its Engine..."Need to Pass a Smog/Emissions Test"...???...............as, that is, what will usually..."Up-Set-the-Apple-Cart"...if a "Carburetor" (and a Host of Other Things), are..."Not, Set-Up"...to..."Satisfy"...that there..."Smog-Sniffin' Bandit"...at, that there..."Smog-Sniffin', Vehicle's Engine, Smog Testing Establishment"..."Yee-Haw"...but, I only be Sayin' that, If-in, I Git, that thar, "Pass" (word") "Stamped", or was it "Printed", on that thar..."Smog Paper", that They give You, after, Takin' Yur "Money"...lol...........(Ok, stop Laff-in, so-zzz, we can Continue....Thank-You...lol).....................................Time to ask You a few things now.............................Does Your "C-10-1/2 Ton-Pick-Em-Up-Truck", have to be..."Smog/Emissions Tested"...???..................................In order for Me, to Not, be Going on a "Wild-Goose-Chase", it would be very beneficial, if You would, so kindly, have a look-see, at Your "Carburetor", and perhaps, tell me the following............................"Name" on "it" (aka, Rochester or...???).................Any Identifying "Numbers, and/or Letters/Words", Cast into/onto, the Carburetor, or, maybe "it" has, something along the lines, of a Metal "Tag", perhaps...oh, and also, the "Year" of Your "Pick-Em-Up-Truck"...???.................................Hey, just so You know, most of what You are Seeing and Hearing, in these UA-cam Videos of mine, are just, some, of the "Many Hobbies", that I'm, shall we say..."In-To".................................Well now, You see my Friend, the More, that You're able to tell me, about the "Patient" (aka, Your Carburetor), the More, I'll be able to help You out....Thanks-ah-Bunch...................Till next time.................Be Safe, take care, and have a good one.
I see many older carb vehicles running far to rich, black smoke and gas fumes! Proper air fuel mixture is far better for more power smooth running, keeps oil cleaner as well. My 72. Nova 350 two barrel Rochester runs to near perfect state of tune!
Greetings...Bill Bright...........Thanks for watching............It's good to hear, that Your 1972 Chevy Nova, is running, good as a Swiss Watch (so to speak).........(I like the Nova, and, I use to ride along with a Friend, while he was driving his Mom's blue 1971 [I think?] Nova 4-door, that had a 250 cubic inch inline 6-cylinder engine under the hood, way back when)...............Lem-me-see-now...a 1972 Chevy V-8, would probably have a Points and Condenser, type of Distributor in/on the engine, unless "it" was Changed/Upgraded to something else............If You're still using the Points and Condenser, type of Distributor, then, I hope, that, the Points Gap/Dwell, is kept at that, about 30 Degrees Dwell specification, cuz, as the Points Gap Changes, (due to, arcing at the points, as well as, rubbing block wear), then, as a result, the Dwell, "and", the Initial (base) ignition timing will Change, as the Mileage starts to accumulate, most times.............Yes-Sir-ee-Bob, the older engines, that didn't have, much in the way of Pollution control Devices, as well as, the usually, quite a bit Leaner Air/Fuel ratios, that those Smog/emission Carburetors were probably calibrated for, were, for the most part, more than likely, calibrated, for a slightly Richer Air/Fuel ratio, generally speaking, that is.............If You are putting Gasoline, that has, oh, about 10% Ethanol (alcohol), in its Blend, into Your Nova's gas tank, then, that alone, will probably be having the Affect, of a slightly Leaner Air/Fuel Ratio, as compared to, having the engine burning 100% Gasoline (without any Ethanol in it what-so-ever), cuz, gotta remember now, that, those older Carburetors, were probably Calibrated/Set-up with, 100% Gasoline, and probably before, those Gas-Pump-Bandits, started to Pump-out, that Gas-em-ah-Haul (that be, the Gasoline, that had Ethanol/alcohol added into its Blend).............Although, just about any Gasoline burnin' engine, will run very well, that, in itself, can't really tell You, what the Real, and Genuine, Smog/Emissions, that are actually exiting the exhaust pipe/s, unless, having the Vehicle Smog/Emissions Tested, at the (smog) Testing establishment, or equivalent, there-of..............Case in point...I had a 350 Chevy V-8, with a 4-mv Quadrajet, sitting on top of the intake manifold, and, I had to take it though the Smog Test, and, my very first time, at that............So, I thought it would be a good idea, to get those 2 Idle Mixture screws, Leaned out a bit, cuz, I had no idea, as to, where they were adjusted at.............I turned in/clockwise, those 2 idle mixture screws, to Lean-out the idle mixture, quite a bit, to the point, where I had them at the Leanest setting, while also, having that Chevy 350 V-8, Idling in gear, and almost as Smooth at Silk, at the very same time............Well, so much for, the Engine sure Runs really well, cuz, after going through the Smog Test, "it" Failed, the (while) idling in gear, part of the smog test...!!! (oh no...!!!...lol)..............Well, it turned out to be, that, I went Too Lean (air/fuel mixture), when I adjusted those 2 idle mixture screws, to the point where, that Too Lean of an idle mixture (adjustment), ended up causing, what is termed, a "Lean Misfire", where-by, that, Too Lean, of an air/fuel ratio/mixture, would-not Burn properly, and probably sent, some Un-Burned Gasoline, through the exhaust system, that didn't have, or required, a Cat/Catalytic Converter on it................The "HC" (Hydrocarbons) were at about 700 +, and the cut-off point, was a @ 500 PPM/Parts per million, as I recall.............Also, a Carburetor's Air/Fuel ratio (mixture) "Varies" as well, depending on, what the engine's Operating conditions are, at that particular moment..............Very Rich, when starting a Cold engine, on a very Cold day, due to the Choke being On (as Gasoline, will condense, on the inside runners, of the intake manifold, until it gets hot enough, as an example)..............Once the Engine, is at Operating temperature, then, it can idle, at about 14.7 to 1 air/fuel ratio, or, a bit Richer, if need be..............Same 14.7 to 1, while just Cruzin' along, at, not too fast of a speed, and some tuners, can easily get into the 15 to 1 air/fuel ratio, on a factory/stock, low compression ratio engine, to increase Fuel Economy..............Here's where it gets "Rich" again, cuz, when You go WOT/Wide Open Throttle...Pedal-to-the-Metal...then, it'll probably be about 12.5 to 1 air/fuel ratio, there-abouts, as an example............Something like a Dirty Air "Filter", can kinda act, some-what like the Choke does, as in, in Restricts, the amount of Air, that gets into the Carburetor, and then, the result usually is, that, More Gasoline, gets sucked into the Carburetor, along with Less Air, which will usually, cause the Air/Fuel Ratio/mixture, to become "Richer", than it needs to be, and then, Fuel Economy will drop/become worse, as a result, and.......till next time........Be Safe, take care, and have a good one.
Greetings...Bill Bright............Nice to hear, that Your 1951 Chevy Pick-em-up-Truck is behaving itself as well...lol.............Ah yes, sure do like those times, where, Ya can spend more time Driving "them", rather than..."FIX-in"...the darn things...!!!...lol...but, then again, when the Engine Ain't Runnin'...Ya get Super Good "Gas Mileage" (as in none, what-so-ever...!!!)...lol...and.......till next time.......Be Safe, take care, and have a good one.
i like the video but i would like doing it with automatic transsmition, because i just put a quadrjet to my c10 and e had problems with the mecanics. how is not they veicles they dont care.my truck parked spend more gas than walking.i appreciate thank you
Greetings mco zpda....Thanks for your nice comment...and...I will give you some information on your "Other" Comment, that will perhaps help You get your "Quadrajet-4-Barrel-Carburetor" Adjusted close enough, in order to have your Vehicle, have a better chance at "Passing" the "Smog" (Emissions) Test....Be Safe, take care, and have a good one.
Greetings mco zpda....Thanks for your comment....I would like to let you know in advance, that, even if you manage to get your "4-Barrrel-Quadrajet" Adjusted properly for the "Smog/Emission" Test, that there are "Many" Other things that can cause your Vehicle to "Fail" (Not Pass) the Smog Test!....You said that Your Vehicle was a "C-10"...is it a "Pick-Up-Truck???...and...what "Year" is it???...what "Engine" Size???, and is it a "V-8"???....Can You See a Model Number on your Quadrajet Carburetor???....I actually "Did" get a "Quadrajet-4-Barrel" equipped "350-Cubic-Inch-V-8" to "Pass" the Smog/Emissions Test a few years in a row, but, the "NOX" (Nitrogen Oxide) Level was almost "Too High" (just Under the Maximum Allowable), because the Vehicle "Did-Not" have an "EGR" (Exhaust Gas Recirculation) "Valve" on the Intake Manifold, and also, my Vehicle "Did-Not" have a "3-Way" Catalytic Converter on it! (2-Way, also referred to as "Oxidation" Catalytic Converters "Will-Not" Reduce the "NOX" Emissions!). If you can tell me as "Much" as you can, about your "C-10", then, I will have a much better chance at being able to help you out, with, getting your "C-10" to "Pass" the Smog/Emission Test. Has your "Quadrajet" been "Rebuilt" Lately, because, if is very Old, it might not Work good enough to Pass the Smog/Emission Test, although, you can still try Adjusting it, and have it smog/emission tested, but, you will still have to pay them the Testing Fee, if it fails. I still have some "Notes" on how I Adjusted my Quadrajet-4-Barrel-Carburetor that was on top of my 350 Cubic Inch (5.7 Litre) V-8 Engine, that was a very "Basic" (4-MV?) Model, that had the "Thermostatic Choke Coil" mounted separately , and it was mounted in a cavity in the intake manifold, as opposed to the "Choke" that was mounted "On" the side of the 4-Barrel-Quadrajet carburetor. So then, if you care to, just let me know, all that you can, about your "C-10", so I don't end up, going on a... ..."WILD GOOSE CHASE!!!"...lol. Till next time... ...Be Safe, take care, and have a good one.
is it true that the throttle plate should be totally closed to make the most vacuum? or i have to follow manufacture inhg ?i want to tune my toyota 2 barrel idle and the idle vac reach 20inhg but the chart says 17 when i open the plate the idle is ruff. You explain how to adjust the carb but just with a base line with the idle mix screws but the idle speed screw whats its base line?
serchmarc Greetings serchmarc....Thanks for watching, and for Your questions as well............................................Each and every..."Vehicle"...usually has "Its" own "Needs", and, has to be "Adjusted/Set-Up", for..."What-Ever-the-Requirements-Happen-To-Be"...along the lines of, oh, let's say..."Does the Vehicle"...have to be..."Smog/Emissions Tested"...???...because, "If" it Does, the "Carburetor", has to have, the..."Adjustments/Set-Up"...to the..."Factory Specifications"...or..."If"..."It"..."Is Not"...there is a..."Strong Possibility"...that, when, that particular Vehicle...gets..."Tested"..."It"..."Will Not Pass the Smog/Emissions Test"...!!! (and yes, I've Experienced, what I was just sayin'...!!!...lol).........................................."If"...Your Vehicle has to be "Smog/Emissions Tested", the First thing, that You should be looking for, is what is usually called, a..."V.E.C.I. (Vehicle Emission Control Information) Label/Sticker"...that's usually found in the Vehicle's..."Engine Compartment"................Hopefully, You will find One, and the "Information", that You will See on It, should be..."Followed/Performed Very Closely"..."If"...Your Vehicle, Needs to..."Pass the Smog/Emissions Test"...that is.............Also, Your Vehicle has to be fairly "Stock", as in, little or No Modifications to It, and, just about "Every Thing", has to be in "Very Good Condition", and "Set-Up/Adjusted Properly", and some of those "Things", happen to be, the "Ignition System", the "Fuel System" (part of which, is the Carburetor), and, something like the "Emission/s System", that was "Installed" by the Factory/Manufacturer of Your Vehicle, when it was "Brand New"..................................................The Factory/Manufacturer, of each and every "Carburetor Equipped Vehicle", pretty much, has, or had, "Their Own Specifications & Methods of Tuning/Adjusting", and that's why, that "V.E.C.I Label/Sticker" (or, if You can Find the some-what "Same Information"), in something like, a "Factory (Chassis) Service Manual", then, as I see it, You will have a much better "Result", mostly, because, that will pretty much be, the "Way that the Engineers/Designers"..."Intended It, to Work/Perform"...just sayin'....................................................Now then, "If" Your Vehicle "Does-Not" have to be "Smog/Emissions Tested", then, what the, shall we say..."Old School"..."Mechanics/Hot-Rodders", pretty much did, as I see it, was to some-what, "Set-Up/Adjust", the "Idle Mixture Screws"...and the..."(Curb) Idle Speed Screw", to Obtain (get), the "Highest Vacuum Reading" (Hg...or...Inches of Mercury), that was Showing on the "Vacuum Gauge", when the Engine, was "Fully Warmed-Up, to Operating Temperature", and having the Engine, at the "Desired/Acceptable Idle Speed", all at the same time........................................................If the Vehicle, had an "Automatic Transmission", then, "Too Fast" of an "Idle Speed", would usually, make the Vehicle "Creep", as in, when the Brake Pedal was Released, the Vehicle would, shall we say..."Take Off" (Move) Too Much, and Faster then wanted, and that was Without Pushin' on the Gas Pedal...!!!...Yikes...!!!....................................You were sayin', about, having the Carburetor's "Throttle Plate"..."Totally Closed", to get the "Most Vacuum"...???..........Well, there are "Very Few Carburetors", that I have seen, where the "Throttle Plates" are "Totally Closed", while the Engine, was at "Idle Speed", and on Those Particular Carburetors, there was usually, a, shall we say, an, "Idle Air By-Pass Screw", for Adjusting the "Amount of Air", that was Allowed to "Flow" Through the Carburetor, while the Engine was at "Idle Speed"...................................................You see my Friend, on most of the "North American Vehicles", that had Factory Installed Carburetors, on their Engines, before "Fuel Injection" took over, well, They Worked, some-what, like the "Thermoquad Carburetor", that You saw, in this UA-cam Video of mine, as in, the "Primary" (Front) Throttle Plates", are "Slightly Open", while the Engine is at "Idle Speed", and, "Not Fully Closed" (Yes-Sir-ee-Bob, no Dedicated, Idle By-Pass Air Adjustment Screw on It, at all...!!!...lol).....................If You "Set the Idle Mixture Screws Too Rich", then, You might "Carbon Foul the Spark Plugs and Combustion Chambers" in Your Engine, as well as, get very Poor Gas Mileage/Kilometer-age, while at Idle Speed, while having the Vehicle standing still, at a Red Light or Stop Sign................................................................................If You "Set Your Idle Mixture Screws Too Lean", and, although, the Engine seems to be Idling alright, and quite smoothly, it could very well be, "Lean-Miss-Firing", and, on one Rochester Quadrajet 4-Barrel Carburetor, that I Adjusted the Idle Mixture & Speed Screws on, a number of years ago, by Ear (aka, Listening to), and even I couldn't tell if it was "Lean Miss-Firing" (Lean Miss-Firing, is when, the Carburetor's, Idle, Air/Fuel Ratio/Mixture, is a bit Too Lean, as in, Not Enough Gasoline in that particular, Idle, Air/Fuel Ratio/Mixture, and the Engine "Miss-Fires", at Idle Speed, because there "Is Not" enough Gasoline in that Idle "Mixture", to make the Engine "Fire Properly/Consistently", as in, "No...Miss-Fire"at Idle Speed), and, even though I couldn't "Detect Anything Wrong"...that there "Smog Sniffin' Machine", at, that there, "Smog/Emissions Testing Establishment"..."SURE COULD"...!!!...lol.........................................So then, if You would like some more help from me, I really need to know..."What Year and Manufacturer of Vehicle"...???..............."What Engine"...???................"What Carburetor"...and Model Number/Serial Number on it...as well as...."Does Your Vehicle have to be "Smog/Emissions Tested"...???............Thanks..............Till next time............Be Safe, take care, and have a good one.
RockysRoadshow hi rocky,, well your xplanation was pretty good, very well writen. the engine is a 3AU with a suspected swaped carb. AISIN 2 barrel simple/normal carb. 1.5cc and manual tranny. Its not gonna pass emission test right now, i probably do that in 2 years. cause the car is parked inside my garage (restoration project).i think the headgasket is making a bad misfire but ill fix that pretty soon. im waiting for my leakdown tester.. i just asked you about the throttle plate ,cause the repair manual doesnt have a base line for example " turn counter clockwise the speed screw until doesnt touch the shaft trigger or "where the accelerator cable is installed" . well , the manual doesnt say that as a start , just star with the typical toyota phrase.. screw all the way in the mix screws and then turn counterclockwise 1and a half turn as a start then blah blah.. I thought every carb needed the most vaccum but as far i understood you.. is to have the most vacuum with the proper rpm and also with a proper emission CO and HC values at THE SAME TIME, is that correct?
serchmarc Greetings serchmarc....I had a look-see, at some Information, on the good ole Internet, and, there happens to be, an, almost "Limit-Less" amount of Information, on just about Anything, and that Includes Your Vehicle as well...!!!...lol.....................................It appears, that, a carburetor, kinda like the One You have there, just might have, a number of Additional Gadgets/Smog Controls, in Addition to, a, let's say, a quite Primitive/Basic Carburetor, that was Manufactured, Before, all of the Smog/Emissions Testing started confronting All of Us.......................................What I would normally be doing, is, seeing if I could get, the "Exact", or, as close to the "Exact Information", as in, the "Information" that is usually found, in a..."Factory/Manufacturers Chassis Service Manual"...on, Your "Exact Vehicle", and, "If"...the "Carburetor", is Different From, the "Original, Factory Installed Carburetor", then, You'll be doing Yourself a big favor, by Finding the "Exact, Factory/Manufacturer's Information, on "It" as well....................................You can also, have a look, and see if You can find a "Website", that has a "Forum", that "Discusses", both Questions and Answers, about Your "Exact Vehicle", as, I'm pretty sure that, You will probably have, quite a few of them, to choose from, once You Find "Them" that is..good luck with that.............................................Now then, about You asking, about..."Vacuum...Proper RPM's....and the CO, and, HC Values"...???......In order to be able to "Pass" the "Smog/Emissions Test"...the Engine has to be in..."Good Shape/Not Too Much Carbon Build-Up, in the Combustion Chambers"...and,..."All Tune-Up and Maintenance Items"..."Should be Up To Date"...and, that also Includes the "Catalytic Converter/s...as well as..."All of the Adjustments"...that..."Apply"...to..."Any Adjustable Components"..."Must be Done Correctly, as per the Factory/Manufacturers Specifications"...or...the Chances of acquiring that Smog/Emissions Test..."Pass"...won't be very good at all..............................You see my Friend, when-ever I have to adjust a "Carburetor", like You see, in this UA-cam Video of mine, I do it, the following way, if it needs to be "Smog/Emissions Tested"...................Please Note, this Information "Only Applies", to this particular "Carburetor"...and..."Not Yours...!!!...lol................For Starters...the Carburetor, has to be in very Good working order, or, if not, I Re-Build it............................The Engine has to be fully warmed up to Operating Temperature, and the Choke is fully Off......................I Use a "Tachometer" (that's on my Automotive Specific Testing Meter), to Indicate the Engine's Crankshaft "RPM's" to perform, what is known as..."The Lean Drop Method" (that's right..."I Do-Not Use a Vacuum Gauge...!!!...but...You might have to, depending on what was Originally, on Your Vehicle's "V.E.C.I." Label/Sticker, if Your Vehicle had one, that is...???).....................................On that Same "V.E.C.I." Label/Sticker, it Also had Information printed on it, showing the Amount of CO, for a given, at Idle Speed, Air/Fuel Ratio, if an Automotive Garage, was using a Tail-Pipe Probe, and the Meter to Display, what the Tail-Pipe Probe, was sampling, in order to to do, the Required, Idle Mixture, and (Curb) Idle Speed, Carburetor Adjustments, to attain, the Label/Stickers "Specifications".........................I'm pretty sure, that the rest of, what I did, as it applies to, Adjusting/Setting-Up the Carter Thermoquad 4 Barrel Carburetor, that looks, really close looking, to the One that You see in this particular Video of mine, can be seen and heard, in this very Video.................Yes, indeed...the "Idle Mixture Screw Settings"...the (Curb) Idle Speed Screw Setting...as well as...the Engine's Crankshaft "RPM's", especially at (Curb) Idle Speed, have to, shall we say "Compliment One Another", and really should be "Adjusted", according to the "Factory/Manufacturers Specifications", in order, to, like I was sayin' earlier, to have..."A Better Chance at Passing the Smog/Emissions Test"...!!!................................If I were to just use a "Vacuum Gauge", it would only, take me as far as, getting to the "Stage", pretty much the Same, as when I Adjust the Idle Mixture Screws, to attain, the Fastest RPM's, Mixture-wise, at that 950 RPM's, that I Set the (Curb) Idle Speed Screw for, and, just "Before", I Started to perform, that.."Lean Drop" (Method) in RPM's, from 950 RPM's, Down to 850 RPM's, which, by the way, "Required" me, to use the "Tachometer", and "Not, a Vacuum Gauge", or, I wouldn't have a Clue, as to, where my HC and CO Levels were at.....................................Now for Excessive "NOX", or, Oxides of Nitrogen"...Tail-Pipe Emissions...............Usually at (Curb) Idle Speed, and at "WOT" (aka, Wide Open Throttle)..."NOX" Emissions, aren't much of a concern, but, at lighter engine loads, and at cruising speeds, oh, somewhere between Idle and WOT, let's say, then, probably due to, a somewhat "Leaner Air/Fuel Ratio", and the, Very Much Increased Ignition Timing (50 Degrees, give or take a bit), if it wasn't for, a Functioning EGR System, the "Increased", Peak Flame Combustion Temperature, would probably, make for some very High NOX Emissions, just sayin'......... .............Too much "Ignition Timing" (Advance Degrees at the Crankshaft), and/or, Too Much "Carbon Build-Up" in the Combustion Chambers, and, if, the Engine had an "EGR Valve/System", Installed On, or Near It, the EGR Valve, and its related Components, have to be, some-what Carbon-Free, and working Properly, or, any One, or Combination, of the just mentioned, shall we say "Items", are not behaving themselves (kinda like Malfunctioning, I guess), then, that "Smog Sniffin' Machine", would be Reporting, some, rather high "NOX Readings", on Your Test Report...!!!...(pssssst...equal, to the "Fail" word)...Yikes...!!!.............................So, I hope, what I was sayin' here, will be of some help to You.......................Yes-Sir-ee-Bob...all it takes, is, just "One Little Incorrect Adjustment"..or a, not working so good "Component/Part"...to make, just about Anyone's Vehicle, to be "Emitting Excessive Tail Pipe Exhaust Gas Emissions"...Over and Above..."The Maximum Allowable"...and, if that be the case...No "Pass" (word), will be seen, Printed on the Report that gets handed to You, at, that there "Smog/Emissions, Testing Establishment"...oh my...!!!.....................................Perhaps, have Your Carburetor "Fine Tuned" for Smog/Emissions Testing, by an Automotive Fix-Em-Up-and-Repair-Establishment, that is Qualified to do so, that has a "CO, and/or HC" Tail Pipe Probe/Meter Testing Unit, as by doing so, You won't have to worry so much, about, not getting it, as Critically Set, without the Equipment, that the "Shop" has............................I really hope, that You can find, the "Exact Specifications" for You Vehicle............Good Luck...........Till next time.............Be Safe, take care, and have a good one.
+Gatewood's Computer Sales & Serv, Inc. ....Greetings Gatewood's Computer Sales & Serv, Inc. ....Thanks for watching.................. Sorry, but I don't have a Video (yet?), on how to, adjust/set-up, the Secondaries, on a 4-Barrel Carburetor at the moment..................If You can let me know, just which, 4-Barrel Carburetor, that You are talking about, then, I will (hopefully), be able to give You some Information, on how You might go about, making an adjustment or two, to the Secondary side of the Carburetor in question, and............till next time..........Be Safe, take care, and have a good one.
+Gatewood's Computer Sales & Serv, Inc. ....Greetings Gatewood's Computer Sales & Serv, Inc. ....Well, I do have, oh, about 24 Carter Thermoquad 4-Barrel Carburetor UA-cam Videos, one of which, Shows/Talks, about, how the Thermoquad's Secondary Air Door Works, along with, a few of the Adjustments, to be looking out for, and "Only Some" of those Adjustments/Settings, on the Secondary Air Door/Valve, can be made "Without Affecting", some of the "Other Adjustments", that have to be made, in the "Correct Sequence/Order of Doing Things", or, the Thermoquad Carburetor, will more than likely..."Not Work So Good"...!!!.................The "2-Things", that can be Adjusted, on the Secondary Air Door/Valve (with-out messing-up the Other Settings/Adjustments), are...the Secondary Air Valve/Door''s..."Spring Wind-Up" (Tension)...and the "Fully Opening Amount", of the Secondary Air Door/Valve, against the Metal-Tab-Stop (as You will see, in my UA-cam Video)..............A Thermoquad Carburetor "Rebuild Kit" or Factory Chassis Service Manual, will usually have, all of the Required Adjustments/Settings, that "Have to be Done in the Correct Sequence"...!!!.............If the Choke Pull-Off, is quite Old, it could Leak Air/Vacuum, Stick, or maybe Not Relax fast enough, which, as I've experienced in the past, makes for a TQ that Runs/Performs like (use Your Own, not so pleasant word here...lol).................Then, there's also, a little teeter-totter like Catch-Lever, that has to grab-onto, the secondary throttle shaft's bracket, but only when the Choke, and its Linkage is Fully Off.............Over the years, when a Thermoquad Carburetor gets Older, and/or, has the Mileage/Kilometer-age piling up on it, then, Parts, like the Floats, Needles & Seats, Choke Pull-off, Accelerator Pump Seal/Cup and Check Valve, etc., start getting old too, and probably, shall we say, worn-out, some-what as well, which, will at times, make-for a Thermoquad, that doesn't Perform, as good as it's able to, and Gas Mileage, might suffer as well, possibly....................You can find that Thermoquad, Secondary Air Door/Valve Video, on my UA-cam Channel...RockysRoadshow...and, I think the Title of it is...Thermoquad 4-Barrel Carburetor (Part 7)...if not, just look for the Thermoquad Video that has...(Part 7)...on the end of the Title...oh, and, if You care to, You can have a look at, the Other 23 Thermoquad Videos as well...enjoy....................If You need any more help at all, feel free to post a comment or question, under any of my UA-cam Videos, and........till next time..........Be Safe, take care, and have a good one.
Greetings grucu....Thanks for Watching, and for Your comment and question as well....In order for me, to be able to even point You in the right direction, as to You maybe, being able to make the required adjustment/s, as it pertains to, what it is, that You happen to want to make adjustment/s to, then, You are going to have to tell me, first, just...What, Car or Truck???...What Year???...What Engine???...Any Modifications or Upgrades at all???....Before I can even consider helping You out with any adjustments what-so-ever, then, just like a "Medical Doctor", I have to know as much as I can, about the "Patient", before I will be able to "Diagnose", and maybe "Prescribe" some "Information", that, I hope, will be able to help You out, in, getting Your Vehicle Running "Great" once again...!!! So then, if You can tell me, as much as You are able to, about the Vehicle, that You want to perform some adjustments on, then, hopefully, I just might be able to...Help You Out... Be Safe, take care, and have a good one.
RockysRoadshow thank You for your answer. My car it's a Chevy Blazer K5 with non original GM 327cui with automatic th350 and Rochester 4MV with divorced choke :)
grucu Greetings grucu....Yes, indeed, it helps quite a bit, when I have some specific information to go on....You are in Luck, well, depending on, just which "Model Year"..."Rochester-Quadrajet-4MV" (4 Barrel Carburetor with Vacuum Secondaries, and, just like You said, the "Bi-Metallic-Coiled-Up-Choke-Spring"..."is"...Divorced, as in "Separated From" the Carburetor, and is installed in the Intake Manifold, and, the actual Actuation of the Choke Mechanism is done via a linkage rod). You had mentioned in Your First Comment, about..."How to Adjust an Idle Speed Screw"...and.."How To Set"...the..."Zero Position"...??? I'm hoping that You are talking about, what is commonly know, as the "Curb Idle Speed" perhaps... The Rochester "4MV" Quadrajet Carb, that I'm very familiar with, is one that "Does Not" have Any "Additional Gadgets" on it, with the exception of a PCV (Positive Crankcase Ventilation) "Port" (as in metal pipe, to connect that slightly larger PCV Hose to), and a "Port" for the "Vacuum Advance" Hose, that connects to the Vacuum "Canister", that's mounted on the "Distributor", and also, a "Port", that connects that quite short Vacuum hose to the (Dual Function) "Choke Pull-Off/Secondary Air Door Regulator". There are a few things that come to mind (mine, that is)... Does Your Rochester "4MV" Quadrajet Carb, have an "Idle Speed Solenoid", or something that Looks, kinda the same, and if I recall correctly, it was probably called a "CEC" (as in...Combination Emission Control) Valve (I think?), and, this so called "CEC" Valve, will usually look much like an Idle Speed Solenoid, with the "Difference" being, that the "CEC" Valve...will "Also" have a "Vacuum Hose" connecting to it. "Warning...Caution", if Your Rochester "4MV Quadrajet" Carburetor happens to have that "CEC" Valve that I just mentioned above, You will have to "Understand" It, before making any Adjustments to it, because, if it is "Not Adjusted Properly", the Engine might "Stall" and "Stop Running", and, if Your Vehicle happens to have "Vacuum Assisted Power Brakes"...then..."No More" (Vacuum) will be available for the "Power Brake Booster"...!!! The Rochester "4MV" Quadrajet, that I know quite well, was like I was sayin' earlier..."Did Not" have an Idle Speed Solenoid...or...a "CEC" Valve on it what-so-ever. You said that You were wanting to "Adjust" the "Idle Speed"...is that "Correct"...??? Make sure that Your "Choke" is Fully "Off" when Your Engine has Fully warmed-up to "Operating Temperature", or, if the Choke's "Fast Idle Cam" is still in "Contact" with the (choke's) Fast Idle "Screw", that in itself, can cause..."Too Fast of an Idle Speed". Please, let me know, if Your "4MV" Rochester Quadrajet has an Idle Speed "Solenoid" or a "CEC" Valve on it, that way, I will be able to properly address, Your...Idle Speed "Situation". Also, is Your Engine..."Idling Too Slow"...or, is it..."Idling Too Fast"...and...weather the Engine is..."Cold"..."Warming Up"...or "Hot"...??? 'till next time... Be Safe, take care, and have a good one.
Greetings blakesupra....In order to Observe the RPM's (Revolutions Per Minute) of your Engine, all that's required is, what is called a Tachometer (or, Tach, for short)....Try to get one that looks something like the "Yellow-Multi-Meter" that you see as my UA-cam Channels Thumbnail Picture, and in some of My Channels (RockysRoadshow) Videos as well....My Yellow-Multi-Meter is very good for doing all kinds of Tests, when it comes to a Vehicle, and then some....This Yellow-Multi-Meter is far more Accurate then that Big Analogue Meter that you see in this Video (Analogue Meter has that Waving Needle/Pointer). My "Digital" (shows Big 1-Inch High Numbers on the Display/Readout) Yellow-Multi-Meter can measure all kinds of things....DC Volts, Ohms (or resistance), DC-Amps, Duty Cycle, Dwell & Tachometer with engines that have a different number of Cylinders, an Audible (tone) that indicates a good electrical circuit with low resistance, and, if that's not enough, I could, as an Option, Buy a Temperature Probe that plugs into this Muti-Meter to measure Temperature! I bought this Muti-Meter within the last 10 Years, and it has more then paid for itself, I must say! I paid about $85.00 Canadian Dollars for it, if I recall correctly....A very worthwhile Investment, if I do say so myself. So, if you can get a Muti-Meter that is able to do, most of what mine can, then that's about all that's needed for the "Average-Joe" working at home, on His or Her Own Ride (Vehicle). Oh No, are you getting that same "Car-Bug" that I got quite a while ago?...You know, Car-Bug, as in working on Cars, Trucks, or whatever, as a Hobby?....Welcome to the Club!...lol. Take care, and have a good one.
My emission testing report before I sent you my info on my 77 Ford T-Bird 350M. This is my fail test report any help you can send me would be greatly appreciated. (HC)-- Loaded Reading 46, Loaded Standard 250 Loaded Result--PASS. (HC)--IDLE READING 729, IDLE STANDARD 250, IDLE RESULT--FAIL. My (CO) IN %--LOADED READING 0.23, LOADED STANDARD 1.50, LOADED RESULT--PASS. (C0) IN %--IDLE READING 6.88, IDLE STANDARD 2.00, FAIL. So, that's where I'm at with my emissions result. Will be readjusting my carburetor and start fresh with it. Hopefully I'll be using your method and make it work, thanks.
Greetings...Rogelio Camarena..........Well, as far as the "loaded" part of the smog test is concerned...(probably means, while the Dyno Rollers are being turned/spun, by the vehicle's tires, and are probably simulating, about 25 Miles per Hour/40 Kilometers per hour, as a guess), then, the "loaded" readings, sure look, to be pretty good, to me, alright..........The, shall we say "Un-Loaded" idle/speed test, is where it appears, that the "not-passing-the-smog-test" shows up..........The carburetor's..."Idle Mixture Screws"...as well as, the..."Curb Idle Speed Screw" (or maybe Solenoid, curb idle speed setting, if so equipped), have to be "Set Correctly", or, more exhaust emissions, over the maximum allowable, will usually be the result..........Also..."ignition timing"...has to be set to "specifications" as well, b-cuz, if it's "not set" properly, then, that can also, have quite the affect, on what the smog-sniffin' machine, might be detecting, as far as, excessive exhaust gas emissions are concerned...........Also, all of the ignition system parts, have to be in very good condition/almost like new, b-cuz, all it takes, is, just one misfiring spark plug, that will be sending excessive/extra/not wanted or needed, exhaust gas emissions, right out the end of the tail-pipe..........Also, if there is a fuel system problem, and/or, a wrong air/fuel ratio (mixture), then, that, in itself, can be the cause of, one or more, "misfiring" (engine) cylinders..........Also, things like the air filter, and the PCV/Positive Crankcase Ventilation, Valve and system, have to be good-n-clean, and not plugged up.............On my very first time, having to go through the smog test, I thought that I should lean-out, the 2 idle mixture screws on the carb, so, I turned the 2 of them, in, as far as I could go, and still have a nice smooth idle..."Wrong"...(that was), b-cuz, I got around, about the same as you got, around..."700-plus"...HC/Hydrocarbon reading...!!!...(maximum allowable, was 500 for me, as I recall), and, that's when I learned, that, by turning the idle mixture screws..."in too much/too far in"...that it caused, what is called, a..."lean misfire"...!!!...(that's usually when, and in this case, was when the air/fuel mixture, became too "lean", at idle speed, and caused that lean-misfire), and I sure couldn't tell, that was so, b-cuz, the engine was idling really smooth at the time............Have a look around, in your T-Bird's "engine compartment/engine bay", for a "V.E.C.I." (Vehicle Emission Control Information)...Label or Sticker...b-cuz, there's usually some good information, that's printed on it, and, if Ya get lucky, it will be showing, the specifications/settings, that could very well be...Smog...related as well..........I'm thinkin', that your 1977 T-Bird, will probably have a (Ford) 2150...2-Barrel Carburetor, sitting on top of, the probably, Windsor (spelling?) 351 Cubic Inch V-8 engine (I've never heard of a Ford "350" before, and, I use to have a 351 Cleveland, a long time ago, as well)............I've spent quite a bit of time, working/messing with the (1972 & 1973) 2100 model carb, and, there's probably not much of a difference, but, visually, there is probably a separately mounted "choke pull-off", on the 2150 model, where-as, the choke pull-off, was actually part of, the 2100 model carb itself, as I recall...........Have a look, for that..."V.E.C.I."...Label/Sticker...and let me know, whether or not, you find one, and we can go from there, if need be............Good luck, and.......till next time.......Be Safe, take care, and have a good one.
Greetings...Roger Stevens.........Thanks for watching.........Each type of Tach/Tachometer, has its own strengths and weaknesses.........If it's accuracy Ya want, then, a digital Tach is probably the way to go, and, an example of one, is shown in several of my UA-cam videos, on this channel...RockysRoadshow...(it's the yellow multi-meter, that's made specifically for automotive use...it has, tach, dwell, duty cycle, dc volts, ohms, dc amps, diode testing, and, it even has, a temperature testing setting on it, that I can use, if I were to purchase the optional probe for it)...so, have a look see, at some of my videos, where it is shown, being in use...enjoy.........The analogue meter (that's the kind, that has a needle, that waves at you...lol), is good for watching the changing, shall we say, trend, of, oh, let's say a fairly low voltage, as it fluctuates up and down a little bit.........A good visual representation, would be, an analogue Tach, that shows the engine RPM's as the engine moves though the different rotational speeds, of the engine's crankshaft.........In time, you might end up having, at least, one of each type, just like me...lol...and.......till next time......Be Safe, take care, and have a good one.
Greetings...jack orr……….Well, a pretty simple way, to get those two quads (2, four barrel) carburetors, idle mixture screws, adjusted reasonably well, would be, to use a "vacuum gauge", to obtain, the "highest" vacuum reading, when the engine is fully warmed up to operating temperature, and is also, at the desired idle speed (make sure, that, the choke is fully off)………...Here's what I would do...…...Engine "not running", then, turn all of the idle mixture screws, in very lightly, until they stop, then, put a chalk mark (or whatever mark), at the 12 o-clock position (as in, pointing at the sky), on each idle mixture screw, for a reference point only...……..Then, turn them all out, oh, about 3 turns out, should be ok, to get, the already warmed up to "operating temperature" engine running (idling)………..Vacuum gauge was already connected to the intake manifold (to measure manifold vacuum), then, you have to decide, what the "target" idle speed will be (try to keep it under 1,000 RPM's, or, the carb/s, might transition into the primary fuel circuit)…(sometimes, the initial timing has to be altered, to get things right, and also, make sure, that, your "total" timing is correct, and not "over-advanced, or, damaged engine, it just might be...!!!)...(total timing is, initial/base, plus, the amount of mechanical ignition timing advance, that, the centrifugal advance weights will provide, when they are "fully" slung outwards).........A lot depends on, just how "aggressive", that your camshaft really is..........Factory/stock cams, are usually easy, to get the idle mixture screws, adjusted well...........As for really, shall we say, "lumpy" cams, then, the "ignition advance curve", as well as, usually, a quite high (in advance degrees), of initial/base ignition timing, that, those lumpy cammed engine's need, to sustain, a reasonable idle..........By trying, to get the lumpy cammed engine, to stay idling, by just turning in, the idle "speed" screw/s (too much), then, a really smoky exhaust, it will usually be..........So, just adjust those (probably 4), idle "mixture" screws, reasonably, the same amount of turns and partial turns out, and try to get the "highest" vacuum reading (measured in Hg, or, Inches of Mercury), on the vacuum gauge, when "both" idle "speed" screws, are set, to your chosen "target" idle speed............It's kinda like a juggling act somewhat, as in, when you turn, one or more idle "mixture" screws, then, the idle "speed" usually changes (higher or lower)..........Just adjust the idle "speed" screw/s, to keep the idle speed, at your "target" (warmed up engine) idle speed, that you want, to end up with........Well, there is some basic stuff for Ya, that I hope will be of some help to you..........Good luck, and.......till next time.......Be Safe, take care, and have a good one.
I have a 4350 carb on a 1976 ford 460 like 59 caddy the rpms drop when i tighten the screws from the get go should I back them off even more then the 4 turns or are the needles shot any help would be greatly appreciated. I failed smog at idle not hat 2500 rpms. Thanks
Rick Bensco Greetings Rick Bensco....Thanks for watching this UA-cam Video of mine.................................................Yes, indeed, getting everything set-up right, can be quite the challenge, at times, when it comes to getting Your Vehicle's Engine to run and behave, in such a manner that will satisfy, that good ole "Smog Sniffin' Machine's" ability to "Sense and Report" any Tail pipe Emissions, that are over and above the required Level of, shall we say, Acceptance, in order to have that nice word, being..."Pass"...printed on the Report, that You receive, after that, good ole "Smog Sniffer" has had its chance to Sample, what ever it is, that's coming out of Your Vehicle's tail pipe..........................................................."If"...???...it all boils down to, just having Your Vehicle's Carburetor, set-up, and adjusted, for Your Engine's..."Curb Idle Speed, and Idle Mixture"...then, as I see it, there are a few options that are available to You................................................First thing to do, is to have a look around in Your Vehicle's Engine Compartment, for what is known as a..."V.E.C.I." (aka, Vehicle Emissions Control Information)...Label or Sticker (usually it's a White Sticker/Label, with some Important "Information" on "It"), that will usually, be very Helpful, in getting Your Vehicle's Engine's Components, set-up & adjusted properly, so Your Engine, will, for the most part, be operating, shall we say..."Clean Enough"...as in, "Limiting" the Amount of "Excessive Exhaust Emissions", that will be Under the..."Maximum Allowable"...that will enable Your Vehicle, to receive that good ole..."Pass"...Stamp of Approval....................................................On at least "2" occasions, I found that, by doing the..."Lean Drop Method"...like I explained, how to do, in this particular UA-cam Video of mine, on "2" Different Carburetors, by a "Lean Drop Amount of 100 RPM's" (RPM's = Revolutions Per Minute, of the Engine's Crankshaft), that by doing so, gave me that good ole..."Pass"...stamp of approval, on my..."Smog Testing Report"...and, by receiving that "Pass", I'd say that, the "100 RPM Lean Drop", that I performed, on "Both" Carburetors, worked rather well................................................If You are not able to find any "Specifications", as in, on a V.E.C.I. Label/Sticker or other-wise, I would probably do the following......................................................Vehicle "Exhaust" is "DEADLY"..."Make Sure" that, there is Plenty of Ventilation and Fresh Air Around Your Vehicle, when-ever Your "Vehicle's Engine Is Running"...!!!.........................................All "Lean Drop"...and..."Curb Idle Speed"...Adjustments, are done with the Vehicle's Transmission, In "PARK", on Level Ground, with the Tires Chalked, and the Emergency/Parking Brake On as well..............Have the Engine Fully Warmed-Up to Operating Temperature..............then, "STOP" the Engine............then, make sure that the Carburetor's Choke is Fully Off...............then, Turn-In Both "Idle MIXTURE Screws" In, until Both of them, are "Lightly Seated", and then put a white chalk mark, on the Idle MIXTURE Screw's Heads, at the 12-oh-clock/up position, then, back them "Out"..."4-Turns" each...............then, I would Connect my "Tach" (as in Tachometer, to see the RPM's of the Engine's Crankshaft)................then, Re-Start the Engine...........then, "Set"...the "Idle SPEED Screw or Idle SPEED Solenoid" (as the case may be) to achieve "700 RPM's in PARK" (automatic transmission)...............then, Adjust the Idle MIXTURE Screws, "One" at a time, Inwards, and later, probably Outwards as well, until the "Highest RPM's" were showing on the "Tach", and, You will have to probably, have to do it several times, in order to get it "Fine Tuned"...............You will probably Notice, that the "RPM's on the Tach", will usually "Increase" as the "Idle Mixture Screws" are Turned "In".................just simply..."Re-Adjust"...the "Curb Idle SPEED Screw or Solenoid"...Back to that "700 RPM's"...After making an Adjustment to the either of the..."Idle MIXTURE Screws".................Once You have established the..."Fastest RPM's"...with, Both of the..."Idle MIXTURE Screws"...while having, the..."Idle SPEED Screw or Solenoid"..."Set At that 700 RPM's"...then, it's just a matter of..."Turning In" (for a Leaner Mixture) the..."Idle MIXTURE Screws"..."Exactly the Same Amount of Turns/Partial Turns"...(please note, Carefully rub off the Old chalk marks, and put on New Chalk Marks, at the 12-Oh-Clock/High position, on those "2" Idle MIXTURE Screws..."BEFORE" Doing the "Lean Drop" in RPM's)...........Just "Remember" to..."Not Adjust the Curb Idle SPEED Screw or Solenoid"...when Doing the..."Lean Drop" (in RPM's) with the..."2" Idle MIXTURE Screws"...or...it just..."Won't Work"...!!!................Also, once You have Completed the "Lean Drop"...Adjustments...then You will have to "Make Sure", that Your Engine's..."Curb Idle Speed"...is "Correct", in RPM's, as shown on the "Tach", when Your Vehicle's Automatic Transmission is placed in "Drive", and, with the "Brake On"...while You are In the Driver's Seat...to the..."Factory/Manufacturers"..."Specification" (should be on the V.E.C.I. label/sticker, if You have one, that is)...................................................If the "Curb Idle Speed", while the Auto-Trans is in "Drive", and with the "Brake On", and You in the driver's seat, needs to be Adjusted, then, just use the..."Idle SPEED Screw or Solenoid"..."ONLY"...to..."Set" the Engine's..."Curb Idle SPEED"...and, for "Safety's Sake", make Your Final "Curb Idle SPEED Adjustment, with the Automatic Transmissions Selector in "PARK"...then place the Auto-Tans in "Drive", while You are in the Drivers seat, with the "BRAKE ON", and see what the "Curb Idle Speed" is, on the "Tach" (please note, the "Tach" has to be seen, while You are in the Drivers Seat, when Checking the Final, Curb Idle SPEED)...and..."Do Not Re-Adjust the "Idle MIXTURE Screws"...or....You'll..."Mess-Up"...the...Carburetor's..."Idle Mixture Settings"...that You originally, and painstakingly, went to all the trouble to go through, just a short time ago...!!!................................................There's "No Guarantee", that My "Lean Drop Settings", will enable You to "Pass" the Smog Emissions test, but it should be very close, just sayin'...........................................You'll have to find out, the.."Specified"..."Curb Idle SPEED"...while in "Drive"...for Your "Exact"..."Vehicle...Engine...and Transmission"...while Your Vehicle's Engine is..."Idling in Drive"...with You In the Driver's seat, as, that is..."Super Important"...in helping Your Vehicle, to have a much better chance at "Passing the Smog/Emissions Test"...!!!................................................Another "Option" is................You can phone around, and see if there happens to be, an Automotive "Fix-Em-Up-Establishment", that has a..."HC/CO" (HC = Hydrocarbons & CO = Carbon Monoxide) Testing Unit, where, the Unit's Tail Pipe Probe, takes a Sample of Your Engine's Exhaust, from Your Vehicle's Tail Pipe, and, then, the "Technician or Mechanic", will be able to "Adjust" Your Carburetor's..."Idle Mixture, and Curb Idle Speed"...to the required Settings, that will give Your Vehicle, a much better chance at acquiring, that much needed "Pass" that You need....................................................Even "If" Your Carburetor was "100%" Capable, of "Passing" the Smog/Emissions Test, that my Friend, is Only "One" part of what is Needed to keep "Exhaust Emissions" with-in Allowable Limits.........................................Here are a few things to consider, which also depends, on the "Type" of Smog/Emissions Test being conducted, for any given Vehicle...................................The Engine itself, has to be in very good Mechanical Condition, along with, not too much Carbon build-up in the combustion chambers/head/s, and even the Motor Oil has to be fresh and clean as well...................................Air and Fuel Filter/s must be Clean......................Now on to the "Distributor"............The Initial/Base Ignition "Timing", plays a "Big Role", in a Vehicle's Engine, that has to be "Smog Tested"................................................Things like, too much Initial/Base Ignition Timing...too much, or too quick, of a Centrifugal/Mechanical Timing Advance...and also, too much, or, too quick of a Vacuum Unit's Timing Advance, will usually "Increase" the Amount of "Exhaust Emissions" as well...!!!...................................................Bottom line here is..................Keep all Parts and Pieces "Factory Stock"...and Use the Vehicle's "Factory/Manufacturer"..."Tune-Up Specifications and Adjustments", for a Vehicle, that has to be "Smog/Emissions Tested"...especially, if it is something, like the "California" (and maybe New York as well?)..."Smog/Emissions Test"...as, not only will the "Sniffer"...be..."Sniffin'...but, I've heard that, they be "Checkin' under the Hood"...and..."Under the Vehicle"...for the "Special Certified Smog Parts", for the Vehicle in question as well...!!!...Yikes...!!!...lol...............................................So then, see if You can find, any and all "Specifications" for Your Vehicle, as that will really help a lot...!!!.......................................I still don't know if You have a Car or a Truck...???................................If You have any further questions or concerns, just let me know, in a comment or two, under any of my UA-cam Videos.........................Good Luck, and, until next time.................Be Safe, take care, and have a good one.
RockysRoadshow Thanks! I have an old RV I drove it 2 years ago from CA to NY and Back. The truck runs pretty good a little bogged down on the hills but not too bad. I just got back from the smog test and my H/c was still not good my co was fine but not h/c at idle bummer I'll try this again from start to finish. Thanks again
Rick Bensco Greetings Rick Bensco....Here are a few more..."Clues"...for Ya, as to what just might be causing Your Engine's, Higher then Wanted, at Idle Speed..."HC" (Hydrocarbon), tail pipe Emissions..................................................If there happens to be any..."Vacuum Leaks"...due to things like..."Miss-Routed, or Disconnected, or Cracked/Split Vacuum Hoses"...or maybe, a...Not 100% Closing...EGR (Exhaust Gas Recirculation) Valve, due to something like, Excessive Carbon Build-Up, which will usually Prevent "It" from Closing all the way, and also, Any "Gaskets" that might be Leaking, that could very well be, causing a Vacuum Leak, as well ................................................If Your Vehicle is equipped with a "Catalytic Converter", It also, has to be Functioning Properly as well.................................................If Your Engine is Equipped with an Air Pump (aka, Smog Pump...lol)...then, "It" has to be working properly, as well my Friend, as "It" kinda works, some-what like an "After-Burner", in the Exhaust Manifold/s, where-by, the "Unburned HC's", that Exit the Engine's, Head/s, Exhaust Ports, gets "Mixed" with that "Fresh Air", that the Air/Smog Pump...Pumps into the Exhaust Manifold/s, which in turn, as I see it, makes for what, I do like to call, an "After-Burner", b-caws, that there "Fresh Air", that is Added to the very Hot "HC's", will enable those very Hot "HC's" to "Continue Burning" in the Hot "Exhaust Manifold/s", b-caws of the Oxygen, that's in the "Pumped-In" Air, makes for a "More Complete Burning", of the "Un-Burned Portion" of the "HC's", while "They" are "In" the Hot Exhaust Manifold/s...................................................The Engine, has to, have had, a Proper "Tune-Up", not all that long ago, and that Engine, has to have, New, or As-New, Ignition and Fuel System Parts & Pieces, along with Clean Air and Fuel Filters, and also, has to be "Correctly Adjusted"...to..."Factory/Manufacturer's Specifications" as well................................................Sometimes, as I've experienced in the past, there was some "Crud/Debris/Yuck-ees", that got Stuck, in my Carburetor's "Idle Circuit"...in around the "Mixture Screw Area"...there-abouts, which had my Car, almost "Stalling" at a Red Light................................................So, I managed to Nurse the Car back home, and, I made a Note, of the "2" Idle Mixture Screw's..."Turns and Partial Turns"...from being "Lightly Seated" and Fully Closed", so that I'd be able to "Set" Them "Back where They were Originally"...................................................Once I "Removed" Both Idle Mixture Screws", I got a hold of a length of Neoprene, Fish Aquarium, Air Pump..."Clear Tubing" (about 1/8 Inch, Inside Diameter, I think), and, like Blowing-Up a Stubborn Party Balloon, I used Lung Pressure, via my mouth, to make like a Mini-Compressor, and I Blew really hard, through the Clear neoprene Tubing, while it was pressed against, each of the Carburetor's..."Idle Mixture Screw"..."Holes"...hoping to..."Dislodge/Remove"..."What-ever-It-Was"...that, what I thought, just might be causing, that..."Not-Working-so good"..."Idle Circuit"..in my Carburetor...........................................Once I "Re-Installed" the "2" Idle Mixture Screws...and..."Back to Their Original Positions"...(and hearing a Drum Roll)...I Started the Engine, and..."Guess What"..........................."ALL FIXED"...and the Engine was Idling..."Just Great"...!!!...(I Bow, and say...Thank-You, Thank-You very Much)...lol.........................................If the Carburetor on Your Engine, has gone quite a Few..."Miles/Kilometers, or Years"...since it has had a..."Complete and Properly Adjusted Rebuild"...as well as making Any...Modifications, as in, something like, Re-Calibrating the Fuel Jets, on a much Older Carburetor, that was probably "Calibrated" for 100% Real Gasoline (that be Gasoline, that Does-Not have any Ethanol/Alcohol in it...!!!), way back when, as opposed to, trying to having that Much Older Carburetor, trying to Supply the Engine, with the Required Air/Fuel Ratio at All Engine, Speeds and Loads, while that poor Old Carburetor is being "Fed" (as in Feed or Feeding) the current day Gasoline, that usually has "Ethanol" (Alcohol) in Its "Blend", which by the way, will some-what make, a Much Older Carburetor, that was Calibrated for the Good Ole 100% Gasoline (that was available, many Years ago), and as I've experienced personally, a Carburetor, while being Fed, Gasoline, with about 10% Ethanol in it, would cause, that particular Engine to..."Lean Surge", while Traveling at City Speeds (Lean Surge, is when the Engine actually Surges, or kinda makes the Vehicle, Jerk, or Buck, back and forth, and I'm sure, that Everybody, while in that particular situation, would actually Feel, that Somethin's Up...!!!) .........................So then, if You care to, and with Your Engine "Cold and Not Running", You can "Visually" Check-For, things like...Missing, Disconnected or Damaged...Vacuum Hoses and Electrical Wiring, and/or, just about Anything that looks like "It's" out of place, or just Doesn't Look Right, just sayin'.................................................Before I forget, just about "Any Vehicle", that actually "Does Pass the Smog Test", will for the most part, be getting "Better" Gas Mileage/Kilometer-age (aka, Fuel Economy), but only If, a Person goes..."Easy on the Gas Pedal"...and, if that Person does, that "Gas-Pump-Bandit"..."Won't be Taking as Much of Your Hard Earned Money"...at as..."Fast-ah-Rate"...as a Vehicle that...."Failed the Smog Test"...and usually gets called, a..."Gas Guzzler" (maybe?...lol)......................................From my experience/perspective, it sure "Doesn't Take Much", along the lines of, shall we say, Something that Isn't Working Properly, Connected Properly, or Adjusted Properly as well, that will cause, just about any Gasoline Engine out there, to be...Spitting/Spewing, Excessive Exhaust Emissions, out of the Vehicle's Tail-Pipe/s, and, that's, pretty much a given (Fact), and, as You've already experienced, that Fact, happens to be...that You...just..."Can't Fool that Smog Sniffer, at the Smog Sniffin', Testing Establishment"..."What-So-Ever"...!!! (aka, "It's kinda like, a "Mechanical"...but Can't Run..."Police Tracking Dog"...!!!)...and lol, but only if it isn't You, that gets handed that "Smog Report"..."With-Out"...the..."PASS"...Word...Stamped On..."It"...!!!............................Ah yes, time for that, good ole saying, and, as I see it, could be applied, to an Engine, that "Won't Pass the Smog Test" (due to somethin'...that just Aint Right)...and that Saying happens to be..."The Chain is Only as Strong as the Weakest Link"...!!!...(or Snap!)...................Good Luck...and........Till next time................Be Safe, take care, and have a good one.
I need to adjust the cold choKe on my quaradrajet--1985 boat motor. The port side motor idles too high until the motor warms up- about 2000 RPM, would be much happier if I could get it down to 1200 RPM--this carb doesn't have the set screw under the vacuum device
Greetings patswil1....Thanks for watching this UA-cam video of mine, and, for Your comment/question as well....I haven't had any "Hands On Experience" with a "Marine Specific" Rochester Carburetor to date, but, I'll mention a few things, that I hope, will help You out somewhat....You had mentioned, that You didn't happen to see, what is normally referred to, as a "Fast Idle Adjustment Screw", and the Fast Idle "Cam", that goes hand in hand with it, Under, what is usually, a Choke Pull-off Diaphragm, that also Functions, as a Secondary Air Door Control/Modulator (aka, Air Valve Dashpot). I had a look see, at some pictures of Rochester Quadrajet "Marine" Carburetors, and indeed, some of the "Choke Control Mechanisms", are "Quite Different", from, what I'm use to seeing, in comparison to, "Land Based" Rochester Carburetor equipped, Cars and Trucks, that are Usually Equipped with that, good ole..."Fast Idle Cam & Adjustment Screw!" If I was in Your situation, I would be looking for a Factory or After-Market "Service Manual" for Your "Exact" Boat/Engine/Carburetor/etc. Also, I would be Visiting some of the Many..."Boat/Boating" Related Web Site "Forums", where, most of the time, there just might be, a Person or Two, that has already "Encountered" the same "Faster-then-wanted", Cold Engine, Fast Idle Speed, with the, hopefully "Correct Procedure", that will Reduce those (cold engine) "Excessive" Engine RPM's to an Acceptable Level, that, will be, in the RPM Range, that will be, acceptable to You. In most cases, all I have to usually do, is, take a look at something, such as, the "Choke Mechanism" on Your Port (aka, Left Side) Engine, and, it sure wouldn't take me very long at all, to figure out, how it operates, and, how to Adjust it as well...but...unfortunately, I'm not there, and, Your Boat isn't here! With "Both" of Your Boats Engines "NOT RUNNING", move the Required Levers and/or Carburetor Linkages (I'm not sure, but, You might need someone else, to operate the Throttles or Choke actuating Controls, if those Controls are located at the Boats "Helm"). Have a look at how Your "Starboard" (aka, Right Side) Engine's Choke Linkage/Mechanism Operates, as it's moving, as well as, the Distance, that the Linkage or whatever Actuates the "Choke Related Gizmos" Travel, and, maybe take some measurements as well. Like they (keep) sayin'..."A Picture is Worth a Thousand Words!"... ...&... ...in this (well, actually Your) case, those so called Pictures, are Actually, what You'll be Seein', if, and when, You happen to Observe, the "Movement" of, those "2", dare I say Identical Engine Control Systems (maybe, with the exception, of, having Controls, being "Specific" for, that of, one for the "Port", or Left Side Engine, and the other set of Controls, for the "Starboard", or, Right Side Engine). Please, be sure, to Run Your Bilge/Engine Compartment "Ventilation System", for the Recommended amount of time, to "Evacuate", any Gasoline "Fumes", that may have accumulated in Your Boat's Bilge/Engine Compartment, "Before" Starting those "2" Engines!!! Best of "Luck", with lowering Your Boat's, Port Engine's, (cold engine), fast idle speed, to an acceptable rpm level. Steady as She goes "Captain", as You Ply those Waters, with Your Vessel's Plotted Course... ...Be Safe, take care, and have a good one.
Greetings...Devlicious............Thanks for watching...........Well, in order to, shall we say..."fine tune"...the idle mixture screws, along with the (curb) idle speed (RPM's), as in, just having the engine at idle speed (idle speed screw, or solenoid adjustment), then, it's pretty much a given, that, the engine has to be running, and, is also up to operating temperature, with the choke fully off...........Here are some adjustments, that, can sometimes be made, while having the carburetor, off of the engine...........These adjustments, are usually called..."bench adjustments"...(as in, on the work-Bench)...........Most carburetor "rebuild kits", will usually have these, so called, "bench" adjustments, explained on the instructions (sheet/s of paper), that come in the kit, that usually have, both, printed words, along with some pretty good pictures/drawings as well............Things like, basic (base) settings for...idle mixture screws...curb idle speed screw or solenoid ...choke linkage and fast idle speed screw...choke door (flap)...and if applicable...secondary throttle plates, and/or, secondary air valve adjustments...etc..........Me, myself, if I don't happen to have any instructions, for carburetors, like, oh, let's say, a...Rochester 2 or 4 barrel carb...a Carter Thermoquad...or maybe, a...Motorcraft/Autolite 2-barrel carb...then, I usually just open the idle mixture screws, about 3 Turns out, from being "lightly" seated, so as not to, cause any damage at all, and, this basic/bench setting, is just to get the engine started and warmed up to operating temperature, so I can do the final, fine tuning, of the idle mixture screws..........If, having to go through the "smog/emissions" test, then, pretty much all adjustments, have to be done, shall we say, "super correctly", or, if not, then, that..."smog sniffin' machine"...will absolutely, be able, to "sniff", that extra, not wanted air pollution, that's exiting the vehicle's tail-pipe...!!!...lol...........Be very careful, so as, not to come in contact, with any, hot or moving engine parts and pieces...!!!...........So, there you have it, well, for now that is, and........till next time........Be Safe, take care, and have a good one.
RockysRoadshow cool thanks I'm rebuilding a 66 dodge charger its a huge learning experience for me I got it for my dad as a project for the both of us last summer but he sadly passed in March so now its up to me to figure out .. Thank you very helpful
Greetings...Devilicious...........Sorry to hear about your Dad, and, I surely do, know how that feels...........1966 Dodge Charger, you say, well, I know quite a bit about the older cars, so, if you need any help at all, just let me know about, as to, what condition, that you want the car to end up in, when, all's said and done, as in, is "it", just gonna be, a daily driver/not too fussy at all, or maybe, you want to keep "it", as factory original as possible, perhaps...???............I'm not sure, but maybe, the 1966, might have drum brakes, on all four wheels, and maybe, manual steering and manual brakes (not power assisted), possibly, etc...........So then, if Ya care to, just give me a shout, when-ever, with, what-ever, and, if I'm able to help You out, so be it...........Good luck, with your Resto (Restoration), or, what-ever it ends up be-in, that will put a smile on your face, and........till next time.........Be Safe, take care, and have a good one.
My 66 has power steering manual brakes drums all the way around and it's a 383 automatic at least it's supposed to be it currently has a 76 440 in it I bought a 67 383 from a 67 Coronet for 300 bucks I was told it knocks when it's cold which my dad told me at the time that sounds like a main bearing because the motor looks like it's been rebuilt it has an elderbrock high rise on it with chrome caps our guess is when they rebuilt it they didn't torque it down right..
Greetings aerial wheel....Thanks for your Input (comment)....I'm guessing that the Word that you posted there, is the Rocket-Science Word for "Carbon Monoxide Poisoning", or, when a Person Inhales a Lethal, or, almost Lethal amount of "CO" (or, Carbon Monoxide, that happens to be One of the Gasses that results from a Vehicles Engine Exhaust)....When (Hopefully Not!) a Person Inhales too much "Carbon Monoxide", it gets into a Persons Blood Stream, and (from what I recall), it "Inhibits" (or, Prevents) the Blood from Absorbing "Oxygen!"....Or, in simple terms, a Person will, shall we say, "Suffocate", for the reason of an Inadequate (or, not enough) Oxygen in the Blood to Sustain "Life!" That's the reason that I try to Always mention about "NEVER" having a Vehicles Engine Running with "CLOSED" Garage Doors!!! "Always", and I repeat, "ALWAYS", have Plenty of "Ventilation" (Fresh Air) whenever your vehicles "ENGINE" is Running!!! Best Place to have your Engine Running, is "OUTSIDE" with Fresh Air "Everywhere!!!"...and...Stay away from your "Exhaust Pipe/s", and any "Exhaust Flow" whatsoever, so I will be able to Talk to You, and, Not About You!!! Take care, be Safe, and, have a good one.
precisely. once a persons hemoglobin becomes carboxyhemoglobin, they can no longer use the oxygen carried in their bloodstream. exhaust leaks and driving with the trunklid or rear hatch open can be dangerous as well. i'm sure you know the dangers, but i always take the opportunity to discuss this subject whenever possible. : )
aerial wheel Greetings aerial wheel....Yes Sir, a Person can never be Too Careful when it comes to Anything, that can become "Lethal" (aka...Life Threatening) to any Human, Pet, Animal, etc. Another thing to be very Aware of, is, during Winter, (if you get Snow where you live or travel), if a Person (driver), and any Additional Occupants in the Same Vehicle, happen to get "Stuck" in a "Snow Bank", "Snow Drift", or any Depth of "Snow" that Prevents the Vehicles "Exhaust" from Venting completely away from said vehicle, then, the "Potential" for that Vehicles Exhaust Gas to get Trapped "Underneath" the Vehicles "Chassis" (Frame, or Under-Carriage), makes it Possible for that Vehicles Engines "Trapped" Exhaust Gas to "Enter" the Vehicle from "Underneath", and "Enter" the "Passenger Compartment", making it "Extremely-Life-Threatening", and "Lethal" in some cases, to the Vehicles Occupant/Occupants!!! Who knows, perhaps Somebody who has, or is reading these Words here, and now, might "Save" their Own Life, but, "Other" Lives as well, if they, or, they see Other People that might just be..."Stuck" in some "Deep" Snow. Take (Extra) care, and, have a good one.
Rocky, you are a genius. I failed smog test twice. Then watched your video and did what you said. Bingo! It passed Oregon smog test with flying colors. Thanks sooo much.
Greetings...diane good...…….You're welcome, and, Congratulations, for tellin' that smog sniffin' machine, who, the real Boss is now...!!!...lol...…….Me, a genius...???...nah, I'm just a part time Grease Monkey, that happens to have automotives, as one of my hobbies, that's all, and, just like, I've probably said a few times in the past, and that is, that, if someone is interested in a certain subject matter, then, it's pretty much a given, that, that person is gonna learn quite a bit, don't-cha-think...maybe...yeah, I'd say so...……..My very first attempt, to adjust the two idle mixture screws, that were on a 4-barrel Rochester carburetor, that sat on-top of a Chevy 350 cubic inch (5.7 liter) V-8 engine, (and, having no catalytic converter at all), was done, just by (my) ears (sound), of the engine, while it was fully warmed-up, and at (curb) idle speed...…….I turned both idle mixture screws in-wards (clock-wise), as much as I could, while still having, a really good sounding & smooth idle, along with, not noticing any miss-firing at all...and...I still received, that Big "Fail" word, printed on the smog testing paper...……...As I recall, at idle speed (only), I was just a wee bit too high, as in, oh, about, 700-plus, and the maximum was about 500 (high reading, was due to, what is called, a "lean-misfire", as in, not enough gasoline in the mixture, which, I didn't detect by ear/sound, and also, "not having", the engine shaking, what-so-ever)...so, not too bad, seeing as how, I didn't do the proper (idle speed) "lean drop" procedure, probably, because I never did it before!...lol)………..Then, there "it" was...Yes-Sir-ee-Bob, I finally saw that "Sticker" (label) that was stuck to the under-side, of the Chevy Van's hood...!!!...commonly, called a V.E.C.I. (as in, Vehicle Emission Control Information, I think?), and the "lean-drop" specifications, were on the sticker, the whole (censored word) time...!!!...lol...……...Perhaps have a look-see, in, or around, your vehicle's engine compartment, firewall, and/or, under the hood as well, and hopefully, if "it" is (still?) there, it won't be hiding, as good as a Sasquatch, is capable of doing...lol...……..The carburetor's idle mixture screw's adjustment, is just, one of many things, that can cause an engine, to Fail the smog/emission test, and it might (some day), turn out to be, a problem, with the ignition system, and can sometimes, result in, a weak or intermittent spark, showing up, between the spark plug's two electrodes, which usually sends, a certain amount of un-burned gasoline, right through, the vehicle's entire exhaust system, and, if really bad, it has the potential, to ruin/destroy, a catalytic converter (or two of them, if so equipped), and then, just repeat after me...expensive...Expensive...EXPENSIVE...!!!...so yeah, always keep vehicle Maintenance in mind, just in case, and...….till next time......Be Safe, take care, and have a good one.
This video essentially got my '79 Dodge American Clipper RV passed smog , with the same carburetor , on a Dodge 440. Thanks Rocky!
+Erik Sanchez ....Greetings Erik Sanchez....You're Welcome, and..."Congratulations"...!!!...I say, for getting Your Thermoquad Carburetor equipped, 440 Cubic Inch V-8 Engine, to be able to "Pass" the Smog/Emissions Test, with the Adjustments that You made...(can You Hear All of the People Clapping in the background...???), oh, and, now that Your RV (Recreational Vehicle), has Cleaner Exhaust Gas, Exiting the Tail-Pipe, You might be having the onset, of a "Mosquito" Problem, when Ur Campin', now that Your RV's...Keep-the Mosquitos-Away-Stink-ee-Engine-Exhast-Gas...is Gone...!!!...lol...................Well, aside from a properly working and set-up Thermoquad Carb, there are a few more things, that have to be working correctly, and/or, adjusted properly/to specifications as well, depending on, just what, and how many, shall we say "Smog Devices", that happened to be Installed on, just about any given Vehicle, when it first, Rolled-Off-of-the-Manufacturer's-Assembly-Line.........................Here are some of the Smog related things, that I've noticed/observed/studied/fixed, and tried to fix...lol...over quite a few years.....................The Distributor's, Initial (base) Ignition Timing, has a lot to say, in respect to, what might be printed on the Smog Testing (paper's) Final (and maybe Not Passing) Result......................If the Engine has an EGR/Exhaust Gas Recirculation System on it, then, that EGR Valve & related System, has to be working really good, or, a Very High NOX/Nitrogen Oxide Reading, it will usually be, as I found out, by actually seeing, just how High the NOX Readings can get, on a Chevy V-8 Engine, that didn't have an EGR System on it, and is as follows......The Lowest NOX, I ever got, (on that particular vehicle), was about 1500 PPM/Parts per Million, and the Highest, was Above 3000 PPM, which, was about, the Maximum allowable, or, Fail, it was...Yikes...!!!.....................Now, I'll mention, some interesting Smog Results, that I got, After Installing, a New 3-Way Catalytic Converter, on a Mid-1990's, V-6 Engine...................Well, due to that old/high mileage, worn-out Cat (Cat = Catalytic Converter), I received that (not so much needed, or wanted) "Fail" Word, printed on my Smog, Test results paper, and, the Over-the-Allowable-Amount, wasn't all that much..........So, after gettin' Smog Tested again, with the "New Cat", I saw a Real Eye-Opener...!!!...Damn, the Smog Readings were about 1/2 (One Half), of the "Average Readings", that all of the Other Similar Vehicles were Getting...Holy-Gwalk-ah-Moly...!!!...now that's Impressive, and, just goes to show, just How Much Smog, a New, and Very Good Working, 3-Way Catalytic Converter Can Remove, when it does a Super Job...!!!.........................Oh, and, a 3-Way Cat, will reduce HC/Hydrocarbon, CO/Carbon Monoxide, as well as NOX/Oxides of Nitrogen...where as...a 2-Way Cat, won't be able to take care of/reduce the NOX what-so-ever, well, from what I recall, that is.............................While Camping, or being Parked somewhere, and, If You're having Problems with Bees, such as Yellow-Jackets or Wasps, getting too close for comfort, then, here's a real neat "Trick", that a Fellow Camper, was tellin' me about, and at the very same time, showing me as well, and is as follows....................Pour some Orange Crush Pop, or something like it, into a See-through, Plastic or Glass Dish, or what-ever, and Locate/Place it "Away From" All Humans and Pets...cuz...those..."Bees" are "Attracted" to "it", like You wouldn't believe...!!!.....................Thanks for tellin' me, about Your Success, and.........till next time.........Be Safe, take care, and have a good one.
wow man ur a great teacher, am about to adjust my boat Carter four barrel carb this weekend, I just order a tach dwell meter after watching this video I know in my hart I can do this. thanks
Greetings...mrbigs g..........I sure do appreciate, Your very nice comment my Friend, and, thanks kindly, for it, as well...........Seeing as how, You were sayin', that, Your Carter 4-Barrel Carburetor, sits on-top of an Engine, that's in Your "Boat", then, if it were me, I probably wouldn't bother, doing the "Lean Drop" procedure, with the 2 Idle Mixture Screws, as I was showing Folks (how to do), in this particular UA-cam Video of mine, and here's why...............Engines, be them, Inboards or Outboards, that are in/on "Boats", as far as I know, have Never, had to be Smog/Emissions Tested, oh, and, thank goodness for that...lol.................I would probably (just), adjust the Carburetor, using a Tachometer (or by using a Vacuum Gauge, will give about the same result), by doing the following..................Have the Engine Fully Warmed Up, and in "Neutral" (Out Of Gear...!!!), and make sure that, Cooling Water is Circulating, while the Engine is Running...............Then adjust the 2 Idle Mixture Screws "Equally", like I was showing (how), in this Video of mine, up to the point "Just Before", I did the "Lean Drop"...cuz, most Boat Engines, will probably, not do so well, with the "Lean Drop" (aka, "Leaner'", Idle Speed, Air/Fuel Ratio/Mixture)..........The "Lean Drop" Method, that I was showing, in this UA-cam Video of mine, had to be done, to get the Car or Truck to "Pass the Smog Test", so then, Boats, need not apply...lol (I think...???).................You can try doing the "Lean Drop" procedure/method, if You care to, and if it does work, without having the Engine "Stall", when the Shift Lever is placed in Forward or Reverse Gear, then, Fuel Consumption, while the Engine, is at Idle Speed, might be a bit better...maybe (with a Boat, it's almost like sayin', Gallons-per-Mile...lol...well, maybe not quite)...............Keep an eye on, Water/Condensation in the Fuel system, as in...in the...Gas Tank...Fuel Lines & Fuel Filter...and the Carb's Float Bowl as well, cuz, Engines, really, don't Run so good, on H-2-Oh/Water...................Due to the rather high Humidity/lots of moisture in the air, that a Boat is exposed to, it's a good idea, to keep an eye on, all of the Electrical Connectors & Connections, cuz of...Corrosion...Oxidation...and sometimes, I've even seen...Green Yuck-ees...too...!!!...which on a bad day, will make for, some very Un-Wanted, Electrical, related Problems, and I hope not.........If You have a Distributor in/on Your Engine, I'll (almost...lol) Bet, that, there "Won't Be", a Vacuum Advance Unit/Canister on it, and it's probably, cuz, once the Shift Lever is placed in Gear, well, with a Boat, it's kinda like..."Going Up a Steep Hill...All of the Time"...!!!...(due to the high load, that the "Prop/Propeller", places on the Engine, as well as, a pretty much, 1-only-Gear-Ratio as well, most times), as opposed to, driving a Car or Truck, which in most cases, does just peach-ee, and gets better cruzin' gas mileage, with the correct Vacuum Advance Unit/Can on the Dizzy (aka, Distributor).................Make sure that, Your Carburetor's Idle..."Speed"...Setting, "Is Not" too "High" in RPM's, cuz, if it is, when going from Neutral, to, In Gear, it might go "Bang"...!!!...and that's not good at all................Then, there's the..."I'm Going Too Fast (at Idle speed...in gear), as I'm approaching the DOCK"...!!!...Yikes...!!! (might be worse than, Forgetting to put the "Drain Plug", back in the Transom..."Before"...the Boat gets Launched, into the Water...!!!...oh, and, if that happens, it will usually make for, some rather good entertainment, for the Folks at the boat launch/ramp, watching "it" happen...!!!...lol for Them, not so much, for the "Owner" of the Boat...!!!)............If You can find the "Specifications", for Your "Exact"...Boat...Engine...Out-Drive/Leg, or whatever You have there, then, all the better...........If You care to, You can let me know, how Ur makin' out, and if need be, just let me know about, any problems that You encounter, along with, the particulars of Your Boat, and.........till next time...Captain........Be Safe, take care, and have a good one.
Thanks for the thorough tutorial. I will be trying this today on my 79 440. I don't need to pass smog I just need it to run well and get the best gas mileage I can.
Greetings...Jesse Metcalfe...........You're welcome, and, thanks for watching...........Well, for starters, have a look-see, in Your vehicle's engine compartment, for, what is known as, a "V.E.C.I." (Vehicle Emission Control Information) Label/Sticker, as it will usually have, some very useful information, printed on it, and, in some cases, if not followed correctly, can sometimes, lead to, an Engine, that won't run very good at all...............Seeing as how, You were sayin', that Your vehicle, had a 1979 440 (big block) V-8 Engine in it, has me thinkin', that, You might have a Carter Thermoquad 4-Barrel Carburetor, that, may very well, have some additional, Smog Control Gadgets/Gizmos on it, quite possibly...???...and, if so, then, depending on, just which Model of Thermoquad (carburetor), it happens to be, then, sometimes, things can be easily adjusted, and other times, not so much.............If Your engine has a Thermoquad carburetor on it, then, there are usually...4 Numbers, with the letter S at the end of those 4 numbers, which will tell us, what the Model, actually is............You can find/see, these 4 Numbers, followed, by the letter S...Stamped into, the Base/Lowest part, of the Thermoquad carburetor, on the Left, Rear corner (as viewed, while, You are sitting in the drivers seat, as an example)............If You can tell me, what those 4 Numbers are, that are followed, by the letter S, at the end, then, I'll do what I can, to help You out, and, if You have another Type/Brand of Carburetor, on Your engine, just let me know, what the Make & Model Number is, of, what-ever, it just might be...thanks, and........till next time.......Be Safe, take care, and have a good one.
Hey Rocky!
This is Ben from Berlin/Germany. Thanks for your tips and your patience!
I just rebuild my TQ following your detailed descriptions.
It is a TQ 9211S, which sits on a Dodge 440(-3??), 727 trany, in a 79' Dodge MB400 Chassis Motorhome. The Carb is an all mechanical model with no solenoids what so ever. Like advised by you, it got every gasket in new, brand new X-Rings, brass floats, new choke pull off. All parts where dry ice blasted and ultrasonic cleaned before reassembly. Just to let you know that I tried my best to work accurate. ;)
Today I tried to adjust the idle mixture screws following your instructions above, but to my major frustration it didn't work at all.
Basic set up: idle mixture screws 3 turns out from fully in, idle at 950 rpm while in (D), parking brake on. (to bad, but the V.E.C.I. sticker seems to be long gone)
But there was no increase of rpm when I turned the screws in slowly. In fact, the rpm slowly dropped while turning them in, until they were fully closed.
Do you have any idea where my mistake could be? Could a contamination at a certain point cause such a behaviour?
Could the fuel level be to high? The floats are set to 29/32 from the gasket surface, I have not checked the wet fuel level.
Tomorrow I will try to find out if there is a vacuum leak by spraying some brake cleaner around.
Appreciative for every hint-> ben
Greetings...Ben/heinz wurzt..............Thanks for watching, and, I'm sorry that I took so long, to give you a reply..............That "Lean Drop" method, that I was showing in my UA-cam video, really only has to be done, if, the Vehicle has to go through Emissions Testing (smog testing)...............If the Vehicle "Does Not" have to be emissions tested, then, as long as, the two Idle Mixture Screws, are set, at the point, where the Highest RPM's are found, while at idle speed, then, that should work really good (providing that, everything else, is working as it should be)..............There is, a, shall we say, sweet spot, as it applies to, the setting of, one or more idle mixture screws...............(the following, "does not" use that lean drop method at all, and also, the engine is fully warmed up to operating temperature, and the choke is fully Off).......Let's say, for instance, that, an idle mixture screw, is already "Set" at that sweet spot, as in, Highest engine RPM, while at idle speed, then, when that idle mixture screw gets turned, either "clockwise", or, "anti/counter-clockwise" (as in, in or out), then, the engine RPM's should start to drop (cuz, the idle mixture screw, is no longer set at that sweet spot, that I was mentioning), or, it might not drop all that much, when going Richer/turned out..............Using a Tach/Tachometer, is just one way to make the idle mixture screw adjustment...............The, shall we say, old school guys, that worked on the much older (and much simpler engines), would probably be using a "Vacuum Gauge", that was hooked up to the intake manifold (vacuum signal), to make the idle mixture screw/screws adjustment.............Having the engine fully warmed up to operating temperature/choke fully off, and at idle speed (I'd do it in Park/automatic, or Neutral/standard transmission, with parking/emergency brake on/wheels chalked with bricks or lumber for safety), then, just turn the idle mixture screw, or screws, as the case may be, in or out, until I saw the Highest "Vacuum" reading, on the Vacuum Gauge's dial, that will probably have, the dial on the vacuum gauge, indicating in Hg (Hg = inches of mercury, as I recall).............Try making the idle mixture (screws) adjustment, while having the automatic transmission in "Park", with engine fully warmed up/choke off, cuz, I'm pretty sure, that, You'll probably even "Hear" the changing engine RPM's, cuz, the engine, will be, shall we say, Free-Wheeling, as opposed to, having, quite a Load, imposed on it, cuz of that automatic transmission/torque converter, making the engine RPM's "Drop", and, will probably also, kinda interfere, with the idle mixture screw/s setting some-what (Yes-Sir-ee-Bob, that's the way I be thinkin' alright...lol)..............So, try doing it in "Park", and, if You care to, You can let me know, how You made out, and if need be, we can try a few more tricks (so to speak)............Good Luck, and......till next time......Be Safe, take care, and have a good one.
Great video
Thank you for this instruction video -- I am installing a new Qjet for a 454 and this is the first clear and easy to understand procedure I have yet to see. I have always had problems with the fine tuning, I do a pretty good job but now I see how to get it right on the money -- thanks again. When I get the job finished I will let you know how it turns out. thanks again.
Greetings Dan Baxley....Thanks for watching this video, and, thanks kindly for Your much appreciated comment....The "Actual" way, in which I was showing people how I Adjusted the "Idle Mixture and Idle Speed" in this particular video, "ONLY" Applies to a Thermoquad Carburetor, similar to this one, and, also "Specifically" to the "Exact" Engine (Dodge 360 Cubic Inch V-8) that, the other similar Thermoquad Carburetor, was installed on, as per the "Specification's" on the "V.E.C.I. (Vehicle Emission Control Information) Label", that was stuck in that Vehicle's Engine Compartment was showing....Although the "Method" that I was showing People, that I used, in order to "Pass" the "Smog" (aka, Emission's Testing) for this Particular Engine and Carburetor "Combination", can, sometimes be Successfully used, on quite a few Engines, with 4 or 2 Barrel Carburetor's, If, the Engine/Carburetor "Combination", are of a "Stock" (aka, Factory, Unmodified) Nature.
I have done the very Same "Procedure" (Method), with a Factory/Stock (No Modification's) 1979-350 Cubic Inch (5.7 Litre) V-8, that was Equipped with a "Quadrajet" Carburetor, with a Turbo-350-Automatic Transmission, but, with "Different" Engine RPM's (Revolutions Per Minute) Specification's, when "Performing" the "Lean Drop" Method.
If Your Engine have been "Modified", especially, with a "Lumpy & Aggressive" Camshaft, then, this good ole "Lean Drop" Method, as I see it, probably Won't Work.
If, Your Engine is Stock, Unmodified, and has the factory Installed "Pollution Devices", connected and working properly, then, I figure that, the vehicle Would stand a much better chance at "Passing" the Smog/Emission's test.
Here's an Example of the "Figures" that I used on that previously mentioned 350 Cubic Inch Chevy V-8, that was Adjusted for Smog/Emission's Testing...
"Please Note", that the following Specification's "ONLY" Apply to this particular Chevy 350 Cubic Inch V-8...!!!
Engine fully warmed up...
Automatic Transmission in "PARK"...(and on level ground, with the parking/emergency brake On, and with, Wheel "Chalks", well actually Bricks, blocking all 4 Tires, to keep the Vehicle from takin' off!).
"Stop Engine", then, set the "2" Idle Mixture Screws "3" Turns Out, from being just "Lightly Seated".
Re-Start Engine, and Adjust the "Idle SPEED Screw", so Engine Idles at 875 RPM's...
then, turn each of the "Idle MIXTURE Screws" In or Out, in order to make the Engine Rev at the Fastest RPM's...(I ended up with each of them, being about "4" Turns Out, from just being Lightly Seated).
...The Engine's (875 RPM's that were Initially Set, will probably "Change" to a Different RPM!), so, just "Re-Adjust" the "Idle SPEED" Screw, back to "875" RPM's....I had to do this a few times, to get it "Fine" Adjusted.
...then, once I got the Fastest Engine RPM's at that 875 RPM's Dialed In (about "4" Turns Out, from being lightly seated), I Turned, "Each" of the "2"..."Idle MIXTURE Screws" in "EQUALLY", a bit at a time (same amount of Turns and Partial Turns) until the Engine RPM's "DROPPED" to 700 RPM's.
So, in essence, I went from "4" Turns Out (from both idle mixture screws being lightly seated), and having the 350 Chevy Engine, running at its Fastest (Idle Mixture) Speed (at 875 RPM's), and, I "Lean Dropped" it to 700 RPM's, which required that, I "Turned In" the"Idle MIXTURE Screws" about 1 1/2 (one and one half) Turns Each, from the Original "4" Turns Out (from being lightly seated), then, those "2" Idle MIXTURE Screws, ended up, being about 2 1/2 (two and one half) Turns Out, from being lightly seated, as the "FINAL" Adjustment!
I actually Confirmed that 2 1/2 Turns Out, with "Both" Idle MIXTURE Screws", from being lightly seated, by, Marking them with White Chalk, and Turning them in, until lightly seated again, then, I backed them out, to that "Lean Drop" Setting, that I marked with "White Chalk", back to the 2 1/2 Turns, from being lightly seated, and made sure, that I made the "Finished" Adjustment, while turning Both Idle MIXTURE Screws in a "Clockwise" Direction! (so the "SPRINGS" on the Idle MIXTURE Screws "Don't" decide to "Adjust" the Idle MIXTURE Screws, when I'm Not Looking!!!)..
...also...there is really No Need to lightly seat the "2" Idle MIXTURE Screws, again, like I did, as I Only did that, cuz, I was really Curious, as to, Actually, How Far Out, the "2" Idle MIXTURE Screws were, from being lightly seated!
In a Nut-Shell...With the Automatic Transmission in Park, I got the (warmed up) 350 Chevy Engine, to Rev its Fastest, at about "4" Turns Out, (875 RPM's), then, "Lean Dropped" it, down to 700 RPM's, by turning "IN" Each Idle MIXTURE Screw, about 1 1/2 Turns, and ended up with having Both Idle MIXTURE Screws Out, about 2 1/2 Turns, from being lightly seated, for the "Final" Setting, as per the V.E.C.I (Vehicle Emission Control Information) Stickers, Required "Lean Drop" RPM's Specification.
If Your 454 Engine equipped Vehicle "Does Not" have to go through the "Smog/Emission's" Test, then, the "Idle MIXTURE Screws" for the most part, can be Adjusted, so, Your Engine gets the Fastest RPM's at the (Curb) Idle Speed, that Your Engine Specifies...
...You can do the "Leanest" Idle Mixture Screws Setting, while the Vehicle is in Park (Automatic Transmission)...
To set Your Vehicles "In Drive" (automatic transmission), "Curb" or "Final" Idle SPEED", is to simply "Set" Your "Idle SPEED" about 100 RPM's "Higher", while You have the (automatic transmission) In "PARK", then, get in Your Vehicle, and, hold the Brake on, as You put the (automatic transmission) In "DRIVE", and see what the Idle SPEED RPM's are at.
If You need to Adjust the Idle SPEED any further, just put the (automatic transmission) back in "PARK", and Re-Adjust Your Idle SPEED Screw accordingly, and, get back in the Vehicle, Brakes On, put the (automatic transmission) In "DRIVE" again, and, repeat, the above sequence if needed...
...Don't Forget, to put the (automatic transmission) back in "PARK" when You're Finished!!! (and the Brakes On Too!!!).
Your Engine might Require a Slightly "Richer" Idle Mixture, to get it to "Idle Smoothly", as Engines are somewhat like People, in that they seem to have "Individual Personalities" as well...!!!...lol.
Just keep in mind, the "Leaner" that You "Set" Your Carburetor's Idle MIXTURE Screws (to a certain point, that is), the "Less" Gasoline, that Your Big 454 Cubic Inch will be "Guzzling" at all of those Red Lights and Stop Signs, because "All" Gasoline Engines (while running), with the Vehicle "Not" in Motion, will tend to get...
..."ZERO" Miles Per Gallon!!!...or...in some cases..."ZERO" Kilometers per Litre!!!
If You like, let me know, what Testing, if any, that Your 454 Cubic Inch Engine, has to be subjected to, as in Smog/Emission's Testing, and any other applicable Inspections, that way, I'll know what will help You out the most.
Till next time...
...Be Safe, take care, and have a good one.
RockysRoadshow
Teh 454 Chevy engine I have is in a 30 motorhome I had it completely rebuilt (stock). Even repainted Chevy Orange. I has about 8,000 on it and I had originally put an Edelbrock 1411 on it, replacing the stock QJ, but guess what, in california the E is not approved, even though you can buy these carbs at Pepboys -- well it would not pass smog because the carb was not approved. Luckily I still had the original QJ, and with the carb I was getting a reliable 8-9.5 mpg. After the rebuild with the Edelbrock the best I could get was 7.5, mostely 6.5, so going back to the QJ I figured would be a plus but 30 year old carb (?) so the smog guys rebuilt it, installed it and it passed smog. That was 2 years ago and after the QJ rebuild the mpg was not any better than the Edelbrock. The QJ seemed to climb the hills better than the E. So, two weeks ago I had to go to smog it again and it passed, went to a different shop, and got the specs back and was told it barely passed, just barely, the emphasized. They told me it was burning all of the fuel, running too rich. The engine, however, has been running really sweet, smooth idle and just purring down the freeway, but the MPG still not as good as before on the pre-rebuild and old QJ. This all led me to decided to forget about messing with the carb anymore so I bought a NEW, Rochester QuadraJet, 800 CFM from Jet Performance and it has all of the Smog fitting required by California smog. It is a 2 Stage model and the bottom plate, where the Mixture screws are located but they are recessed and look like they take a special tool to adjust. I did pull the old plugs and installed new ones -- that was a job. And I replaced the HEI cap and rotor with new. Now I am getting ready to install the New Crab. Here is the reading from the smog station -- This is all greek to me, just going on what they said.--
at 704 RPM HC (PPM) AVE: 57 -- MEAS 71
The CO (%) AVE .70 -- MEAS 1.06 --
at 2478 RPM -- HC (PPM) AVE 33 - MEAS 21 --
The CO (%) AVE .30 - MEAS .91
It passed so I am happy about that, so i have two years before I have to do this again but i wanted to know how to set up thin new carb and that is when I found your posting, love it, cleared up a lot of misdirections finding at other places. Any advice is really appreciated. Thanks for being there Rocky
Dan Baxley
Greetings Dan Baxley....You're welcome, for...my being here, there, and almost everywhere...lol...and, thanks for Your nice comment, my Friend....First thing I should mention, is, about Your newly acquired "Jet Performance 800 CFM Quadrajet Carburetor, and, about what You said, about, needing to have a "Special Tool", to "Adjust" the Idle Mixture Screws....Drum Roll Please...It so happens, that I have a UA-cam Video, on How I made my Own..."Special" Idle Mixture Screw "Adjusting Tool", and hopefully, the Idle Mixture Screws, in Your new Jet Performance Quadrajet, has Similar "Heads" on the Idle Mixture Screws, as can be Seen, in the UA-cam Video that I made a while ago...
Dan, you can find the UA-cam Video, that I just mentioned above these words, on my UA-cam Channel...RockysRoadshow...and, the Title of that there Video is called...Rochester Quadrajet Dualjet Idle Mixture Plug Removal, Plus "Special" Tool!!!
Maybe, have a look at my UA-cam Channel...RockysRoadshow...and You may very well, Find some Helpful, and perhaps Educational Information, that is contained in those very Videos...Enjoy.
Oh, where to start...
A Person, always has to remember, that, the Gasoline that is being sold these days, for the most part, is being "Blended" with "Ethanol" (aka, Alcohol), which usually causes Carburetors, that were "Calibrated" for that good ole Gasoline, and for example, using a Carburetor, of oh, about 1974, let's say, would more then likely, cause that 1974 Carburetor, to be administering a "Leaner" Air/Fuel Ratio, to the Engine, because, the Higher the %-age (per-cent-age) of Ethanol in the Gasoline "Blend", the "LARGER" the "Fuel Jets" usually have to be, and, in some cases, to prevent "Lean Surging", as I have experienced in the past.
It would help, if I knew what "Year" Your Motorhome and Engine happen to be, because, of the Many "Different" Types, of applicable Smog Equipment & Devices that were Installed on Your 454 Engine, as well as, what "Type" of Catalytic Converter was installed..."2-Way" or "3-Way ??? (if there is one, that is).
EGR Valve? (aka, Exhaust Gas Recirculation, and, there are many Variations of this Device as well).
Air Pump (aka, Smog Pump) ?
Then there are all kinds of Vacuum Devices, such as Delay Valves, Thermally activated (coolant) Vacuum controls, and, the list goes, on and on...
Sometimes, as with Your "Original" Quadrajet, the "Nitrophyl" (black plastic Float) has been known, to "Absorb" Gasoline, and this will cause Your Float, to start "Sinking", which will cause a Very "Rich" Air/Fuel Ratio, and may very well have been what caused Your Original Quadrajets "Rich" running condition.
Not to mention, that, a "Dirty" Air Filter, will also cause a "Rich" running Carburetor, due the the "Air Flow Restriction", that it causes. (the Engine has to "Breathe!"...lol)...and...Your Engine Needs a Nice "New" Air Filter, to help make Your 454 Engine "Pass" the Smog/Emission's Test!
Your Fuel Filter/Filters, have to be Like New, and Not Plugged Up in any way, or, it is possible, that it will cause Your Carburetor to run "Lean" (air/fuel ratio), which may very well cause, what is termed, a "Lean Miss-Fire".
A "Lean Miss-Fire", in most cases, will usually Send "Unburned" Gasoline through Your Exhaust System, and, The "Smog-Sniffin' Machine will usually "Detect' and "Report" a higher then wanted High "HC" (Hydro-Carbon, or just basically, Gasoline that wasn't completely Burned).
If You happen to "Set" Your Idle Mixture Screws "Too Lean", this will also cause a "Lean Miss-Fire", so, don't be tempted to go to "Lean" when setting them.
Even though, that "New" Jet Performance Quadrajet, that You have there, that has the Correct "Exterior" Fittings and such, might help Your 454 Engine to Pass the "Visual Test", it won't Guarantee, that the "Calibration" (aka, Fuel Jets Sizes, Air Bleeds, Float Level Setting, etc.) will be Set-Up in the way, that is required, in order to "Pass", that, good ole Smog/Emission's Test....Only, the Smog/Emission's Test Itself, will determine that, Your New Jet Performance Quadrajet is Set-Up, and, Calibrated Properly, to keep the Engine's Exhaust Emission's at a "Pass-able" Level.
If Your Motorhome Has a "Catalytic Converter", it has to be "Functioning" Like New, or, that Smog-Sniffin' Machine will let You know.
You had mention something about a "2-Stage-Model" ???....I'm not sure, just what You mean by that, perhaps, let me know, if You care to.
Before You Installed the "New Spark Plugs", did You "Set" the Spark Plug's Gap? (between the 2 Electrodes).
I have a UA-cam Video on, "How To Set The Spark Plug Gap" as well.
Those Smog Numbers that You posted, look to be, not too bad.
I did notice, that You indicated CO% "Twice", with Different Numbers.
I'm thinking that, one of them is, "NOX" ? (aka, Nitrogen Oxides).
Here's some Food For Thought...
"HC" is short for Hydro-Carbons....Simply put, just Unburned Gasoline.
"CO" is short for Carbon Monoxide....Carbon Monoxide is Lethal (aka, Deadly)...!!!
If Inhaled, it enters the Bloodstream, and "Prevents" the Blood from Carrying "Oxygen" throughout the Human Body, and, basically, a Person "Suffocates" (Internally), and, if Inhaling too much of this Deadly Gas, that poor Person "Dies"...!!!
"Always" have Plenty of Ventilation (aka, Fresh Air), whenever "Any" Fuel Burning Engine is Running...!!!
"NOX" is short for Oxides of Nitrogen....The "X" denotes, that there are more then "1" Type of Nitrogen Oxide, in this Mix.
NOX is the result of, what is normally referred to, as, "Peak Flame Combustion", or in simple terms, When Very High Temperatures Occur in the Combustion Chamber/s, as the Air/Fuel Mixture is Burning, which in turn causes the excessive NOX.
To combat this NOX stuff, they came up with a few things.
EGR System, (Exhaust Gas Recirculation), which includes the EGR Valve itself (the Older Ones, kinda look like a little Space Ship...lol).
When the Engine was fully warmed up, and at light throttle, while mostly Cruising along, the EGR Valve would allow Exhaust Gas (from the engine), to be introduced, along with the Air/Fuel Mixture, that the Carburetor provides, thus, basically, "Diluting" the Air/Fuel Mixture, in order to Keep that "Peak Flame Combustion Temperature" Down, to "Reduce" the Amount of "NOX" that starts heading its way, out of the Engine, and out through the Exhaust System.
Hmmmmm, maybe I should make some kind of Smog video...?...lol.
Have a look see, in or near Your Engine Compartment, for a V.E.C.I. (Vehicle Emission Control Information) Sticker/Label, as, that will be of some Major Help!
Till next time...
...Be safe, take care, and have a good one.
RockysRoadshow
Thanks for taking the time -- the motor is a 1983 454 Chevy, in a 1984 Revcon motorhome. No cats -- dual exhaust. I returned the Jets Quadrajet, turns out it has every thing but the goose neck in the throttle linkage, drivers side, to accommodate the TRC throttle lever actuator which appears to be an intricate part of the Emissions on this engine. I finally found out it is a feature put on some big trucks and mothers homes but seems to be missing on most cars of same vintage. So, I am stuck.. Originally when the engine was rebuilt I had an Edelbrock manifold and an Edelbrock 1411 carb installed -- the carb did not pass smog because it was not an approved carb. I'm thinking about putting it back on and then when smog time come around again (2 years from now) I will swap it back out for the old original Quadrajet? So, would the set up for the Edelbrock 1411 be the same as you demonstrate in the video? Also, should I put a heat shield gasket down under? And if it is a good idea to put a heat shield insulator gasket under this carb, should I also use the metal plate Edelbrock has for converting the Edelbrock Performer manifold with top cut for a Quadrajet, or can I just use the heat shield gasket? Thanks, Dan I am going to check out more of your videos -- love the detail.
Dan Baxley
Greetings Dan Baxley....Seeing as how Your (Original) Quadrajet carburetor is a 1983 Model, that alone, has me thinkin', that it may very well be, something along the lines, of being a "Feed-Back" Type of Quadrajet, with Extra Gadgets, and also, an ECU (Vehicles on-board Computer) perhaps?....But sometimes, Trucks, and maybe Motorhomes as well, might not have been equipped with this Feed-Back Carburetor System, as the Cars were, during that time period....If You take a look, usually on the Driver's Side, of the "Original" Quadrajet, You should be able to see some "Numbers" Stamped on it....If You could tell me what these "Numbers" happen to be, I just might be able to find out, what "Gadgets" and such, that were Engineered in to it, by the Factory that made it in the first place.
Did You look around in Your Motorhomes "Engine Compartment" (or anywhere in Your Motorhome) for a "V.E.C.I" (Vehicle Emission Control Information) "Sticker/Label" at all yet???
That VECI Sticker/Label, might just be, Worth, its weight in Gold!
There is some Important Information on that thing!
With Your Edelbrock Carburetor, the most "Important" thing is, to "Make Sure", that when Both, the Primary and Secondary Throttle Plates (aka, Butterflies) are "Opened-Up", as far as they will go, as in Full Throttle (aka, Pedal to the Metal), that Both the Primary and Secondary Throttle Plates "DON"T" get hung-Up, or hit any part of the Intake Manifold, or the "Adapter", if You so choose to Install one, between the Top of the Intake Manifold and the Bottom of the Carburetor!
I know that most Quadrajets, that I have seen, are known as "Spread Bores" (Smaller Primary Throttle Plates, with Larger Secondary Throttle Plates)...
...where-as...
I'm thinkin', that the Edelbrock, is referred to as, a "Square Bore" (carburetor), and that just means, that, "All-4" Throttle Plates, are the Same Size.
It is Always a good idea to "Insulate" Engine "Heat" from the Base of a Carburetor, "Especially" if, the Carburetor is made of "All Metal", and also, given the "Confines" of the Engine Compartment that is found in Motorhomes and Vans, that Don't Allow as much Cooling Air, as most Cars seem to have.
When an "All Metal" Carburetor gets Too Hot, the Gasoline becomes Less Dense, making for Less Power, and might even cause Vapor Lock, which has been know to cause poor performance, and hard starting too!
If not being Smog Tested, You can simply Adjust Your Idle Mixture Screws, to give the "Highest" RPM's, at about, something like 700 RPM's in PARK (that 700 RPM's get dropped back by the Idle SPEED Screw, each time the Idle MIXTURE Screw/s make the RPM's go Higher, that the 700 RPM's "SET" by the Idle SPEED Screw.)...or...for Less Fuel Consumption, You could do a "100-RPM-Lean-Drop" (with the "2" Idle Mixture Screws), so You end up with 600 RPM's, "WITHOUT" Touching the Idle SPEED Screw. (go In Equal Amounts with Both Idle Mixture Screws, to get Any Lean Drop Setting).
The Above Lean Drop Setting/s, may, or may not, allow Your 454 Engine to Idle "Smoothly".
(Remember to Always make Your Idle Mixture and Idle Speed Settings, with the Engine Fully Warmed Up, and with the Automatic Transmission in PARK!)
Just simply, Slightly "Richen", Both Idle Mixture Screws, an Equal Amount (opposite of a lean Drop...lol), until, Your 454 Engine is, Idling as smooth as Silk, or if not, at least in the same Ballpark, and remember to Re-Set Your Idle Speed accordingly.
Check Your Idle Speed Specification, and hopefully, You will find that Specification, on the VECI Sticker/Label, that should be Stuck somewhere in Your Motorhome.
Once You are satisfied with Your Idle Mixture Setting, just Set Your Idle SPEED Screw about 100 RPM's Higher then the Idle SPEED that You want, (when) the Transmission is in PARK...then, when You step on the Brake, and put the Transmission in DRIVE, Your Idle SPEED (while in DRIVE), will Drop in RPM's, and should be pretty close...if not, put the Transmission in PARK again, and Re-Adjust, then Check Idle SPEED in PARK again, with the Brake On...then just Smile!
Be careful, especially if Your Original Quadrajet carb was Computer Controlled!!!
You don't want to "Fry" any of the Electrical Components, including the Motorhomes Computer (if it has one, that is), by leaving Wiring and Connectors Un-Attatched, and maybe Shorting to Ground, or causing an Electrical Strain, by having something Disconnected!
In other words "Look before You Leap!" (aka, do some Research, before You Modify Anything!).
I hope that, all goes well...
Be Safe, take care, and have a good one.
Very helpful video! thank you!
Greetings...p costa...…….You're welcome, and, thanks for watching...………Well, I kinda learn as I go, and, I learned quite some time ago, just how, to do this particular procedure, which I know, really does work, cuz, if Ya don't do it correctly, then, that smog-sniffin-machine, at the smog testing station, will probably be printing that Big Fail word, on the test paper results…!!!...lol...and.....till next time......Be Safe, take care, and have a good one.
Saved my ass. Thanks man.
+Ascended696 ....Greetings Ascended696....Thanks for watching...............You're welcome, and I'm glad, that this, shall we say, Generic way, of basically setting a Carburetor's Idle Mixture Screw/s, just might help, reduce the amount of Smog, that spews out of a Vehicle's Tail Pipe/s, enough, so the Smog/Emissions Test Paper, ends up having that nice "Pass" (stamp of approval) printed on it (hopefully)...and..........till next time.........Be Safe, take care, and have a good one.
Rocky, you are a true genius! would you have anyway to show this procedure on a multiple carb set-up I have a 4x2 Rochester set-up. Thanks, Jack B.
Greetings...mrjacplumb………...Thanks for the nice comment, and thanks, for watching too...…...Me a genius...???...nah, more like a guy, that cracks too many corn-ee jokes, along with, a somewhat, over-active imagination, most of the time, I be thinkin'...…….Lem-me-see now, hmmm...4x2 setup...???...…….Would that be....two, four barrel...carburetors, that are mounted, on top of, the specific type of intake manifold, having, one, in front of the other one, which is commonly referred to, as being a...dual quad...(carburetor setup)...perhaps...???...……..Here are a few things, that might help you out...……If the vehicle "does not" have to be smog tested, then, it will be much easier to adjust the idle "mixture" screws (if Ya have to go through the smog test, then, just let me know)………….If "both" carburetors, provide the air/fuel mixture at idle speed, then, keep in mind, that, the idle mixture screws should be adjusted about the same turns out, from being lightly seated in the carburetor, to keep things, relatively balanced, so to speak (also, as I recall, there are certain, dual quad applications, where, the intake manifold runners/tunnels, might not flow, the air/fuel mixture "equally", to each of the engine's cylinders, which might have, some cylinders, running leaner or richer, than, some of the other ones, and, if this is the case, then sometimes, one or both four barrel carbs, might have fuel jets, that have different orifice/hole sizes, on the left or right side of the carb, so that, the air/fuel mixture, will end up, being about the same, inside all of the engine's cylinders, oh, and, if too lean, of an air/fuel mixture/ratio, in any of the engine's cylinders, while going pedal-to-the-metal, then, that alone, can destroy, that poor ole engine...!!!)………….I was just telling You, what I did, just in case, the idle mixture, that, the carbs deliver, might not be, shall we say, "balanced" (aka, equal), in each of the engine's cylinders...……..If not being smog tested, then, I would just use, an engine..."Vacuum Gauge"...to adjust the idle mixture screws (if you are running a, shall we say, aggressive camshaft, then, there are some other things, that will have to be taken care of, as well)……….First thing, is to decide, just what, your...Idle Speed...will be...???...then, continue on (please note, I always set the idle mixture screws, and, the idle speed screw, while the automatic transmission is in..."Park"...for safety reasons, and also, have plenty of fresh air/ventilation, around the vehicle, when the engine is running, or, Ya might die, because of poisonous fumes...!!!)………Here's an example for Ya...…….Having the engine fully warmed up/choke off, I want to end up, having an in-drive (automatic transmission), idle speed, running at 600 RPM's (stock, not modified engine)...so then, I set the idle speed to 700 RPM's in Park, to do the vacuum gauge, idle mixture screw adjustment (I'll later address, that final in-drive idle speed)………..What I'm aiming for, is to get the "highest reading", showing on the "vacuum gauge" (this usually means, that, the carb's throttle plates/butterflies, are closed, as much as possible, hence, the highest vacuum reading, showing on the vacuum gauge, oh, and, after all, when Ya take away, the carburetor & gasoline, then, the engine, really is, just a big ole air pump, when Ya really think about it).........The idle "speed", might go higher or lower, when adjusting the idle mixture screws, so, just re-adjust the idle "speed" screw, back to, 700 RPM's, then, re-adjust, the idle "mixture screws, for the highest vacuum gauge reading (it's sure is fun, tryin' to explain, how to git-er-done, using only words...lol)………..When all of the idle "mixture" screws, are adjusted, resulting in that, good ole, "highest", vacuum gauge reading, then, it's now time, to adjust the final "in-drive"...idle "speed" (please, pay close attention, to those two words, being, idle "mixture", and, idle "speed")……….So then, assuming that, we now have the highest vacuum gauge reading showing on the gauge, while having the automatic transmission in "Park", and engine is idling at 700 RPM's (engine at operating temperature/choke fully off), then, all that's left, is to end up, having the engine idling at 600 RPM's, while the automatic transmission is in "Drive" (example only...!!!).........Engine idling at 700 RPM's...Foot on Brake...put in Drive, and using a fairly accurate Tachometer, see what the RPM's are...???....too high, or, too low in RPM's, then, always make the idle "speed" adjustment in "Park" (again, I say...for Safety reasons...!!!)...then, foot on Brake...put it in Drive, and see what the Tachometer (aka, Tach), is reading, and repeat, if need be, until Ya end up with that (example only...!!!)...600 RPM's in Drive..........So then, You decide, what the RPM's will be, at idle "speed", when the auto-trans is in Drive (when the engine, is fully warmed up to operating temperature, and when, the choke if fully off), and just go about 100 RPM's, "above", your "final" idle "speed", to make those (now famous...!!!...lol), idle "mixture" screw adjustments..........If what you see here, isn't enough for You, to git-er-done, then, just give me a shout, and I'll see what I can do for Ya.........Good luck (with your gas guzzler...lol), and......Be Safe, take care, and have a good one.
On my 67 nova 283 with a carter carb. I just put the setting where you put yours, 3 turns out, 1/2 turn in, lol
Hey Rocky, thanks for the quick response. Sorry, my mistake not paying attention on the 350 Ford. After reading what you sent back on the 350 I should've wrote 351 Modify Ford. Sorry about that and will keep you up on my resetting and see what the outcome ends up, thanks Roger.
Greetings...Rogelio Camarena...........You're welcome, and, there's no need to be sorry, at all, my friend, b-cuz, after-all, we're only talkin', a difference, of "only"..."1-cubic inch"...lol..........When you were sayin', about, a 351..."MODIFY"...Ford (engine), then, depending on, just..."what"...???...was "Modified", as far as your Engine is concerned, then, that alone, can make all the difference in the world, as to, being able to, "Pass" the Smog Test..........Here's a pretty good example for Ya..........Let's say, that, a quite "aggressive", Performance Camshaft gets installed in the engine, that, results in a rather, not so smooth idle/fires kinda intermittently, at idle speed...........Well, I'm kinda thinkin' that, the HC's/Hydrocarbons, as well as, the CO/Carbon Monoxide..."levels/readings"...would probably, end up being, "way over", the "maximum allowable"..." exhaust gas/emission level/s"...that were specified, by the smog testing establishment............If you care to, you can let me know, just which..."Modifications"...???...that were made to your engine, that way, I'll have a much better idea, as to, what you're up against, when it comes to, trying to, receive, and see, the "Pass" (word), printed on, your Smog Testing, print-out/document/paper, and.......till next time.......Be Safe, take care, and have a good one.
Great Simulation! Thanks!
Greetings...yogiberra47.................You're welcome, and, thanks for the nice comment, and for watching too.............Getting an Engine, to just Run good, is one thing, but, things get really, shall we say, "Precise" (somewhat), as it applies to, just about Everything, that affects, the Amount of Pollutants, that are found, in the Exhaust Gas, that is Exiting the Vehicle's Tail Pipe/s, during, that good ole "Smog Test" (aka, Vehicle Emissions Test)..............Even, if, all of the Settings/Adjustments are good to go, that's only one part of, what will Help the Vehicle, to be able to Pass the Smog Test............All Wiring...Vacuum Hoses...Smog Gadgets/Devices...Catalytic Converter/s (if applicable)...Spark Plugs...(just to name a few), have to be in really good shape (almost like new, somewhat), and working properly, cuz, for example, all it takes, is one, very small (ignition, or fuel system related) "Misfire", and that Smog Sniffin' Machine, will be Reporting, that not so liked, "Fail" word, on the Smog Testin' Report (card...???...lol).............I think, that, I recall hearin', that, in California USA, Vehicles, that are 1975 or Older, are Smog Exempt...???...and maybe, that might mean, No Smog Testing required...???...oh, and, if so, that to me, is, as good as, avoiding a..."Migraine Headache"...!!!...especially so, if the Vehicle in question..."Fails" the "Smog Test"..."More"...than..."Once"...!!!...Yikes...!!!...lol...and.......till next time........Be Safe, take care, and have a good one.
great video I will use it to dial in my trans am quadrajet carby. it was rebuilt but seems to backfire and big down under acceleration. if I roll on slowly it revs up but any quick throttle seems to make it bog down and misfire.
+evilswingythingy Greetings evilswingythingy....Thanks for watching, and for, Your nice comment as well..............................I've rebuilt, Set-up/Dialed-in, several Quadrajet and Dualjet, Rochester Carburetors, over the years, and had some very good Performance, and some pretty decent Fuel Economy as well, if I went easy on the Gas Pedal, that is...lol.................................First thought that crossed my mind, is, for You to have a Look in Your Trans Am's, Engine Compartment, for, what is known as a V.E.C.I. Label/Sticker, and if You happen to find one, then, that my Friend, will usually have some good information printed on it, that, might be be tellin' You, things like, the Factory Recommended Procedure , to Set the Idle Mixture Screws, and the Curb Idle Speed Setting, for Your Trans Am's, Rochester 4 Barrel Carburetor, as well as, Your Distributor's, Initial/Base (Stock/Factory) Ignition Timing Setting as well, providing that Your Trans Am's Engine and Components, are rather Factory/Stock in nature, that is.............................Try this...Run Your Engine, the Day "Before", You do the Following, in order to make sure, that Your Quadrajet's "Float Bowl", has Lots of Gasoline in it, or, the following "Test", will "Lie" to You...!!!.............................Now, it's the Next/Following Day, and...having, Your Engine "Cold and Not Running", Remove, Your Engine's, Air Cleaner Housing's "Top/Lid", and, while Moving Your Carb's Throttle Lever, with One Hand, Look Down Inside, Your Carb's, Primary/Front Throttle Bores (You'll probably have to, with Your other Hand...Hold Open, the Choke Plate, in order to see this)...to make sure, that, Your "Accelerator Pump", is "Squirting 2 Strong Streams of Gasoline", cuz, "If One or Both Streams of Gasoline, are Weak or Intermittent", then, You have probably found Your Problem, "Acceleration-wise", that is, and, make sure, to Re-Install, any of the Parts and Pieces, that You Removed, Before You Start Your Engine............................Then, as for Your Carb's "Secondaries", meaning the 2, Larger, Rear Throttle Bores, that have that Air Valve Door/Plate, on the Top of them, then, here are a few things to consider..............................The Choke Pull-Off, (looks, kinda like, a little space ship...lol), in most cases, "Also Controls the Opening Rate", of Your Quadrajet's, Secondary, "Air Door", so, "if" You are still Using the "Old Choke Pull-Off", they/the Old Ones, at times, can kinda, get some-what "Stuck, or Stick", or, maybe, Move Too Slowly, making for a Secondary Air Door, that "Doesn't Open, at the Proper Rate", if at all...???...(when Malfunctioning, in the Not Opening properly sense, the Secondary Air Door/Plate, kinda Acts like the Choke Plate, Over the Primaries does, as in Way Too Rich, of an Air/Fuel Ratio), which, as I've Experienced in the past, can make, for an Engine, that sounds rather Sick, and kinda goes "pop...Pop...POP", when-ever getting on the Go Fast Pedal (aka, Gas Pedal)..............Then, there is, the "Torsional" (twisting motion)..."Wind Up Spring"...that also "Controls the Opening Rate/Amount", of that Secondary Air Door, as well...............................If Nobody messed with the Setting, it should be, oh, shall we say, In the Ball-park, setting-wise, that is...............................If You happen to have, the Rebuild Kit's, Instructions/Paper, then, Your Rochester Quadrajet's, Settings/Adjustments..."Specifications"...should be printed on it/them..............................That Secondary, Air Door, "Wind-Up Spring", can be Adjusted, if need be, and, in most cases, it only requires a Small Allen Wrench, to, both, Unlock & Lock, the Secondary, Air Door's "Torsional, Wind-Up Spring", well, once the Correct Setting is determined, that is..................................Air Filter and Fuel Filter/s Clean...???.............................Fuel Pump, Pumping as it should, as in, both, proper Pressure and Volume as well...???.....................................Ignition Timing plays a very Important Role as well, so, make sure, that, the Ignition Timing, is Correct.............................All Ignition Components, have to be in Like-New Condition, and things like Spark Plug "Gaps", have to be Verified, and Set, if need-be.............................Have You been keeping up with "Maintenance", as in, Change/Replace, any & all Parts, as recommended, by the Pontiac/Trans Am's, Owners/Service Manual, and, also, having/doing, a proper "Tune-Up" as well...???...as a well Maintained, and In-Tune Vehicle, will Perform much better, and, if You can keep the Lead (Led) out of Ur Foot, then, Fuel Economy, it will be...lol......................I have quite a few "Automotive Related Videos", on my UA-cam Channel...RockysRoadshow...and, if You care to, You can have a look at them, if You so wish...enjoy...and, if You leave a comment/question or two, I'll do what I can, to help You out...................Also, if You want to let me know, about Your Trans Am, as in Year, Engine, and any Modifications at all, then, for the most part, I can be a bit more Specific, and, a little less Generic, with the Help, that I'll be able to give you...thanks...................Well.....Till next time............Be Safe, take care, and have a good one.
+RockysRoadshow
Thank you for that thorough reply. ok to start here is the vehicle info:
1980 Turbo Trans Am Indy Pace car (301 turbo engine)
rochester only built this carby for one year only model#17080274
i purchased this on ebay fully rebuilt new parts and cost almost $750
i had to replace the incorrect carby which was off a 79 olds and had no connection
for the pevr as well as not having the power piston control via extrrnal means.
now that is all replaced and Pevr rebuilt and tested.
I did a basic procedure you suggested in the video and noticed the vehicle only backfired once but
apart from that it allows me to press the accelorator to the floor, but.?...its still very sluggish and i noticed
after doing this procedure the idle seemed to be slightly up and down.
new plugs gapped to forum reccomended size, new air filter and air hat, new fuel pump (old one was leaking into crank), full oil change and filter, new fuel filter as well.
it is a dog to start and always needs to be turned over 4 to 5 times with a few pumps of pedal, and when it starts it wont let you press the accelrator or it will still. you have to sort play with tiny little presses on pedal to get it warmed up.
once its warm it idles fine.
i will try some of the suggestions you made to see what difference it make.
i noticed the EGR valve doesnt seem to work (attached mytyvac and it wont function).
timing is set to stock and all leads and plugs are firing as well.
+evilswingythingy Greetings evilswingythingy....Well, it's sure a good thing, that, You did get the "Proper, One and Only, Factory Rochester 4 Barrel Carburetor", for Your 1980...Pontiac 301 Turbo V-8, and hopefully, it was Rebuilt Properly, along with, the Correct, Factory Designated Parts (as in Part Numbers/Calibration/Sizes of Jets and Metering Rods, etc.) as well (I hope)...............................The 2 Secondary Metering Rods, in Your "Exact" Carb, from what I saw, are quite a bit "Richer", as in, will provide a much Richer Air/Fuel Ratio/Mixture, when Your "Secondaries" start coming in, to help Cool Your "Turbo Equipped" Engine...................Now for that PEVR/Power Enrichment Vacuum Regulator.............It appears that, a Turbo-Charged Engine's, Intake Manifold's, "Vacuum/Pressure", is quite a bit different, when compared to an Engine, that Doesn't have a Turbo on it, and that's pretty much Why, there is the PEVR System on Your Turbo 301.................On an Engine, that Only has a Quadrajet Carb, sitting on top of a Regular Intake Manifold, then, to Control the Power Piston (inside the Carb), that makes the Primary Metering Rods (2 in this case), go up and down, inside the 2 Primary Fuel Jets, in order to Regulate, the Air/Fuel Ratio/Mixture, there is a Spring, trying to Push the Power Piston "Up", and, if the Vacuum Signal (manifold vacuum), Under the Power Piston, is, shall we say Stronger then the Spring, and in this case, while the Vehicle is just Cruising along, not too fast, the Power Piston Stays Down (unless there happens to be a Cam, on the primary throttle shaft, where-by, the power piston, will go as low, as that Cam will let it)......................When the Manifold Vacuum Signal Drops "Below", the Opposing Spring Pressure, like when You do a Wot/Wide Open Throttle Acceleration (Pedal to the Metal), the Power Piston Rises "Up" as high as it can go..............................Primary Metering Rods "Up" = Richer Air/Fuel Ratio/Mixture, due to Smaller Diameter of Metering Rod in the Jet..........."Down" = Leaner Air/Fuel Ratio/Mixture, due to Larger Diameter of Metering Rod in the Jet.........................Now then, Your "Special Rochester Carb", has an "Extra (vacuum) Hole/Passageway", leading to Your Carb's Power Piston, and, with the help from Your PEVR (Valve), and the rest of that System, the Power Piston/Primary Metering Rods, will be able to Rise Up, to the Richer Air/Fuel Ratio/Mixture Position, otherwise, due to the, shall we say, "Messed-Up, Turbo-Charged, Engine's, Intake Manifold's, Vacuum/Pressure Signal", and Not Having the Power Enrichment System (including the PEVR...Valve) in place, or operational, the Primary Rods, during certain conditions, would stay Down, when Not Wanted, in the Lean position, and a Lean Running, Turbo-Charged Engine, while under a Load, "Is Not a good thing", and, Engine Damage, it just might be...!!!.................................Next time, You happen to have Your HEI/High Energy Ignition Distributor Cap "Off", have a look, and see, if You can see, that, the Ignition Module, has a "Total of 5 Pins" on it (2 on 1 end, and 3 on the other end of it), and hopefully, it is the Correct One..........................Then, there's supposed to be a "Control Box", that takes the Signal, from a Knock Sensor (1 or is there 2...?), if there happens to be, an Engine..."Knock"..."Ping"...or..."Rattle" (as in Detonation or Pre-ignition), and Your Engine's Distributor, should be Retarding/Taking out, about 20 Degrees (Crankshaft Degrees, or was it Distributor Degrees, as Distributor Degrees are 1/2 of Crankshaft Degrees)...???...of Ignition Timing, and, once the Knock goes away, I believe that, the Ignition Timing will Advance, back up to a point, just before that dreaded Knock takes place (I hope)............................The "Advance Weights", inside Your HEI Distributor, could be Sticking or Stuck, and, if so, that will cause any Engine to Run like (use Your Own Bad Word Here...lol)................................On Your HEI Distributor, there should be some Identifying Numbers, Stamped on the Outside, of the Largest Diameter (Aluminum), just below, where the Distributor Cap mounts..............................Make Sure, that, those Numbers "Are the Correct Ones", on Your Distributor, for Your 1980...301 Turbo Engine, just in case, as, I'm pretty sure, that, the Ignition Advance Curve (Weights & Springs), are Set-Up & Matched, for the needs of Your 301 Turbo...............................Also, make sure, that, Your Vacuum Advance Unit/Canister, is the "Exact One" that goes with Your Special HEI Distributor, as there are So Many Different Ones Made, and, Having Different Degrees of Vacuum Advance (those Vacuum Advance Degrees....were they Crankshaft Degrees or Distributor Degrees...it's Important to know...!!!), as well as, how many Inches of Mercury (Hg), that, "it," Starts (pulling) at, and Finishes (pulling) at, as well...!!!...Yikes...!!!.......................Idling Up and Down...???...could be a Vacuum Leak, or, maybe, the Idle Mixture Screws are Too Lean (too far in), or, one is in more, or out more, then the other one, perhaps, as in Un-Balanced...................Pumpin' the Gas Pedal while Cold...???..................................If Your Engine has Not been Running for a few Days, Your Rochester Carb's Float Bowl, might be on the Empty Side, as, Gasoline will somewhat Evaporate, and, just think now, the last time You Drove Ur Trans Am, how Hot the 301 Engine was, and how Hot, the Turbo and the Hot Exhaust Pipes/Tubes got, and turned Your Engine Compartment into an "Oven"...!!! (Gasoline might get Evaporated, with a Hot Metal Carburetor...don't-cha think...???...lol)..............Difficult, Cold Engine Starting...Incorrect Starting Procedure, or, could be, that Your Quadrajets "Choke" is not Set-Up properly, as in, having the Choke Plate, Close Fully, before You turn the key, and/or, the Choke Plate Doesn't Open, the required amount (vacuum kick/vacuum break), once the Engine Starts................................Also, the Fast Idle Cam & Linkages, have to be set to Specifications, and the Fast Idle Speed Screw (Fast Engine RPM's), has to be Adjusted correctly, etc............................About Your "EGR/Exhaust Gas Recirculation" Valve...Not Holding Vacuum........well, some are "Designed that way"...Say What...???...lol...Your EGR Valve, might be the "Positive Pressure Type", that Depends on Exhaust System "Back Pressure", to travel up the EGR Valves Hollow Stem/Shaft, and, when there's enough Exhaust "Back Pressure", it Activates a little Valve, up near that Big, rubber-like Diaphragm, and when that Little Valve Closes, then, and only then, will Your Not so Mighty...Mighty-Vac...become Mighty, once again...!!!...lol..........................Then, there is also, supposed to be, a "Negative Pressure EGR Valve", that, from what I recall, would be used on a High Performance Engine, where "Negative Pressure" would Activate, that Little Valve (if it works that way, that is)................................Your Pontiac 301Turbo, is quite the Engine alright.............Special Crankshaft..........Strong Engine Block..........Maybe, has a High Pressure Fuel Pump, about 10 PSI/Pounds per Square Inch Fuel Pressure (I'm use to seein', about 5 to 7 PSI)................Maybe a High Pressure Oil Pump..."60 PSI"...there-abouts as well, perhaps..............Another thing to watch out for, is, usually, the Higher the Per-Centage of Ethanol (aka, Alcohol), that's in Your Gasoline, the "Leaner Air/Fuel Ratio/Mixture", that, one of these Older Carbs, will be administering to Your Engine's Intake Manifold, and in the case of a Turbo-Charged Engine, that's Not a very good thing at all..............................I hope that, Your Trans Am's Exhaust System, isn't too Loud, so You can Listen for any...Pinging...Rattling...or...Knocking...coming from Your Engine, and if You do Hear any, Park Your Trans Am...Get it Fixed... so Your Pontiac 301 Turbo Engine...Doesn't get Damaged/Destroyed...!!!..........................Don't forget now...They Don't make Pontiacs...Any-More.................Well........Till next time.......Be Safe, take care, and have a good one.
+RockysRoadshow
I Printed all the notes you created and will run through them today.
So far the NEXT DAY TEST passed 2 x nice squirts of fuel in the primary.
I also checked the timing and its at factory set 8 degress.
Tested the distributor vaccuum advance using the old MightyVac and I worked fine as well.
I will start a channel for the 301T and add all the info about it and work I am doing on it.
thank you for the time you took to research my car and caby as Its as very unusual motor and layout that most mechanics know nothing about.
speak soon
What setting is the Fast Idle screw set to when you started this project?
You didn't mention that.
Should i have it all the way snug tight by hand?
the mixture screws should be 3 full turns out right?
Greetings...Cb BroWnN........Thanks for watching.........Was it the..."Fast Idle Screw"...or, the..."Curb Idle Screw"...???...b-cuz, they happen to be, two different kinds of animals, so to speak..........Fast Idle (is controlled by the fast idle screw adjustment, while it is making contact, with the fast idle cam/or lever) and, is only in use, while the engine is cold, and, while just warming up..........Curb Idle (speed), is only working, when the engine is warmed up to, about operating temperature, and, the choke (system), is fully off..........It's usually, only, the two Idle Mixture Screws, that get turned all the way in/clockwise..."Very Gently"...until, each one of them, comes to a stop (so, as to...Prevent Damage, to their tapered, needle-like tips, and the little hole that they go into)..........The two, idle mixture screws, being adjusted to, 3-Turns out (from being Gently seated to a stop), is just a rough starting point, so the engine, will at least, run ok, until it fully warms up to operating temperature, then, from that point/rough setting, the (idle speed) Air/Fuel Ratio, will usually become Leaner, as the 2 idle mixture screws are turned in (not too much/too far), in a clockwise direction (from that rough setting, being, 3 turns out, from being gently/seated to a stop)............Perhaps, watch this Video, a few more times, and see, if it helps you out at all...........So then, just let me know, if it's the "Fast Idle Speed"...or, the..."Curb (slow) Idle Speed"...(or, maybe Both...???), that you want to know more about, and.......till next time.......Be Safe, take care, and have a good one.
I have a 9128S made for the IH Scout for my 1979 Scout II with 345 V8 and 727 auto trans. I bought it supposedly rebuilt to IH OEM specs. It started up first try but was fast idling at about 2000-2500 rpms and once it warmed up it went to about 1400 rpms. So I turned out the fast idle to about 1800 and curb idle to about 750 rpms. When I drove it the first time, it dies when I give it a lot of gas. I can ease it up to speed but cannot punch it without it stumbling and dying. Do I need to go through the idle mixture screws tuning you show in this video? I'm getting an analog engine analyzer so I can know rpms exactly. Any help greatly appreciated.
Greetings...Tracy Dixon...……..Thanks for watching...…….Well, if the idle "mixture" screws, are adjusted good enough, to have your engine idling nice and smoothly, then, that, in itself should be ok, thus far...…….Here are two things, that can cause stumbling, on an aggressive/full throttle take off...…….Does the vehicle accelerate alright, when driving normally (if not, then, it'll usually be, something wrong with the accelerator pump system)………..If the normal driving acceleration is alright, then, we'll move on to the secondary's "air valve"...……..Having the engine "Cold", and "Not Running", push the "stem", that comes out of the choke pull-off (look like a little space ship), all the way in, then, release it, and watch closely, how it extends outwards, to its maximum length...……..A good choke pull-off "stem", should come out smoothly, and reasonably, straight out as well (not leaning to the side)………..This test, is a pretty good indicator, as to, the condition, of the rubber-like diaphragm, that's hiding, inside of the choke pull-off...……The choke pull-off, regulates the opening rate (time-wise), of the secondary air valve...………..There is also a torsional (wind up) spring adjustment, for the secondary air valve too...…….On one side, of the air valve's shaft (end), there will be an outer locking ring, which can be loosened, with a good fitting screw driver, and, once it is loosened off, the secondary air valve, should flop open (vertical)………..The inner screw head (isn't a real screw at all, it just connects to, one end of the torsional wind up spring)………..So then, once loosened, adjust that outer locking ring, so there is a slight drag (resistance), when using a smaller screw driver, to adjust that (smaller) inner screw head...……..Start turning the inner screw, until, the rear most side, of the air valve, comes up, and just touches the boss/stop, that is part, of the Thermoquad's, top aluminum casting...…….Once that stop point is made, then, the additional turns/partial turns, could be called, the spring wind up (amount)………….My Thermoquad, has a specification, of 1 and 1/4 (one and one quarter) turns, spring wind up...…….Maybe try 1 and 1/2 (one and one half) turns, to see if it helps or not...…….Once, the spring wind up adjustment is made, make sure to tighten the outer locking ring, or...oh oh...it will be...lol...…….Shouldn't need any more, than about, 2 turns, on that wind up spring, or something else, isn't, as it should be...…….You can also try this...…...Once the engine is fully warmed up, shut it off, and, put a cover (tin foil or plastic bag), on top of the Thermoquad, so, any potential, small flying parts, don't get inhaled by your engine...!!!...then, disconnect that metal rod, that goes from the choke pull off, to that curved/slotted bracket, that's on the air valve's shaft (end), and, remove bag, from top of Thermoquad, etc. ……...then, test drive...results...??? (better or worse...???)………..I did a modification, that eliminated that rod, from the secondary air valve, on a standard transmission car, and, Wowsers…!!!...went crazy good...!!!...but, I had to drill a small hole, in that straight arm (that's, close to, that curved/slotted bracket), and, had to make, a new/shorter link (rod), so the choke would still work (Yes-Sir-ee-Bob...that choke pull-off, has two duties/things to do, alright)………..Fuel pump ok...??? (fuel starvation, possibly)………..So then, if you are still having trouble, then, just give me a shout...…….Good luck, and...….till next time...…..Be Safe, take care, and have a good one.
Vehicle in question failed hydro carbons at idle?
Hey, this was a great video. It is something that I enjoyed working with on my vehicles. The only problem is i have not been able to find my VECI on my 77 350M Auto Ford T-Bird. The only info I'm going by is the engine valve cover info. Calling on 650 RPM on neutral, park. Question? Is this good info to go by.
Greetings...Rogelio Camarena...........Thanks for the nice comment, and for watching too.........About the only time, that, the Idle speed RPM's become important/fussy, is usually when, the vehicle has to be "smog/emissions tested", and, if the idle (speed) RPM's, are either too high, or, too low, then, that, in itself, might cause extra/not wanted smog/emissions, as well as, the testing equipment itself, might also be "Monitoring" the engine RPM's @ idle speed, to make sure that, it is with-in a certain range (possibly)............If I recall correctly, is that, the smog testing establishment, that I used to go through, might not even test a vehicle, that has an engine, that idles @ 1100 or more RPM's (that's pretty darn high...don't-cha-think?)...........You were sayin'....650 RPM in Park or Neutral (automatic transmission)...sounds reasonable to me, but, that 650 RPM, while in Park or Neutral, will probably drop down, oh, maybe about, 100 RPM's (ball-park figure), once Ya put the Brake on, and shift that auto-trans into Drive (gear), and might end up at, about 550 RPM's there-abouts, maybe (when the auto-trans, is placed in drive/brake on)...........If I happen to have an older carbureted engine, that doesn't have to be smog tested, then, here's what I usually do, to choose an Idle RPM (speed), once I have the Idle Mixture screws, adjusted reasonably well..........With a Tachometer, or, just by, what I hear & feel (so to speak), I adjust the Idle "RPM/Speed" screw, while the Automatic Transmission is in "Park" (for Safety reasons), then, with the foot Brake "On", I place the auto-transmission lever into Drive, to see, just how much the RPM's have dropped down-to.........If, it dropped too Low, then, I go back into "Park", and adjust the idle RPM's a bit higher, and then, foot brake On, and repeat as needed, until, I'm satisfied with the actual Idle Speed RPM's, while having the foot Brake "On", and, the auto-trans in "Drive".........If the Idle speed RPM's are too Low, then, the engine will probably be idling, shall we say, kinda lumpy/roughly, and not so smooth at all..........If, the Idle speed RPM's are too High, then, the vehicle will usually "Creep" (ahead, while in Drive) too much/too fast, as soon as Ya release the foot Brake...!!!...and, that's not so good, or, safe either..........Somewhere around, oh, about, 600 RPM's (give or take a bit), while the auto-trans is in Drive, with the foot brake on, and the engine is up to operating temperature/choke fully off, should be alright, for most of the older carbureted V-8 engines, that don't have to be smog tested, as I've experienced in the past..........Depending on the engine, some of them can idle, at a really low rpm's, probably more so, if the vehicle has a Standard transmission/with a Clutch, and, probably b-cuz, the engine, only has to, shall we say, "Free-Wheel", as in, no drag imposed on it, like an Auto-Trans, will be subjecting the engine to...........If you need any more help at all, just let me know, what "Exact" Carburetor (2 or 4 Barrel)...???...and, whether or not, your T-Bird, has to be Smog/Emissions Tested as well, thanks....and.....till next time.......Be Safe, take care, and have a good one.
I just bought a 1976 corvette with a 350 engine, with automatic transmission, and it has an Edelbrock carburetor installed, the person I bought it off of failed the emissions test. The HC was 3.73 and CO was 4.44, the maximum allowed for HC is 2.50 and for CO is 2.00 to pass emissions test. Could you please tell me how to adjust the Edelbrock carburetor so I can get it to pass emissions.
Greetings...Kift1991...……..Thanks for watching...…….I will mention a few things first, before I move on to, your Edelbrock carburetor, that, will probably help you out quite a bit, when it comes to, lowering your Vett's, exhaust emission level/s, which will probably, increase your chances, at passing that, good ole smog test...…….All ignition related parts, have to be in, as, good as new condition, and, adjusted to specifications.........Have a look in your engine bay/compartment, for a V.E.C.I. (Vehicle Emission Control Information) "label or sticker", and, if you find one, then, there will be, some very useful information, that will be printed on it, and it might also have, a diagram/picture or two, on it as well, possibly....……..A 1976 Corvette, would have probably had, one or two catalytic converters, as part of the exhaust system, when the Vette was brand new, and, this (Oxidizing, type of) catalytic converter, when working properly, would "lower", both, the Hc and Co, emission levels...!!!..........As I recall, General Motors (including, Chevy/Chevrolet, that made the Corvette), started to, (factory) install, catalytic converters, starting around 1975, that were known as, the "Oxidizing" type, which only, shall we say, burn-up, Hc (Hydrocarbons), and, Co (Carbon Monoxide, which is "Lethal", if a person breathed in, too much of this stuff...!!!), and, if your Vette, had, one or two catalytic converters, that were worn out, or maybe, it/or them, as the case may be, might have been, removed from the exhaust system, and, if so, then, the Hc and Co levels, will probably be, a bit higher then wanted.........Hopefully, your engine is very close, to being "factory stock", because, something like, a high performance/heavy breathing camshaft, will probably, increase the amount of Hydrocarbons, and maybe, Carbon Monoxide too (not sure)............All it takes, is, a spark plug, that "misfires", just a little bit, and that alone, will more than likely, increase the emission level/s, into, that not wanted, "fail" category...........The Initial (base) ignition timing, should be set at, the factory recommended setting, because, any "extra" ignition advance, will usually increase the emission level/s too, just so Ya know..........Now then, onto your Edelbrock carburetor..........Hopefully, your Edelbrock carb, is not too old, and worn too much, because, things tend to get, gummed-up & dirty, with age, and, lots of use...........If it were me, then, I would probably do a...100 RPM (Revolutions Per Minute)..."Lean Drop"...idle mixture screw adjustment, with the engine up to operating temperature/choke fully off, while having, the automatic transmission, set in..."Park"...with the emergency/parking brake on, while the Corvette, was on level ground, and always, have lots of "fresh air", whenever the engine is running...!!!...so the Carbon Monoxide (gas), does not Poison you...!!!.........Just watch this video of mine, until you understand, how to get the best/fastest idle speed, while keeping the RPM's at the target level (RPM's, not too high, or, it will get all messed up...!!!)...........Make sure, that, you know, what RPM's, that the engine should be idling at, while the engine is hot, while the automatic transmission is in "Drive", while you also have your foot, firmly on the Brake Pedal...!!!..........If you have a V.E.C.I. label/sticker, then, those idle "speed" RPM's, while in Drive, with the Brake on, should be printed on "it"...........If Ya don't have a V.E.C.I. Label/Sticker, then, try...600 (idle speed) RPM's...while in Drive/Brake On...engine hot..........If Ya find, that, your Corvette "creeps" ahead too fast, when you take your foot, off of the brake pedal, for your liking/personal preference, then, Ya can try lowering the RPM's, just a little bit.........If Ya can get the idle speed RPM's, that were "specified", for your "exact" Corvette and Engine, then, that, in itself, will probably be, your best bet, for increasing your chances, at passing the smog test, well, while at idle speed, that is..........Do they do a "visual" inspection, for all of the smog, parts & pieces at all...???..........Is your "NOX" (oxides of nitrogen), within, the "Pass" limit...???...if not, then, just let me know, and, I'll give Ya a few pointers, on that one as well..........Good luck, with getting your Vette, to pass the smog test, and.......till next time.......Be Safe, take care, and have a good one.
I have a 79 Lincoln Mark V two-barrel 400 and I can get to one of the adjusting screws on the right hand side of facing the carburetor what instrument do I need to get to that one I can only adjust it from one side but I can't adjust it from the other my hands don't fit and I can't see how I can get an instrument in there
Greetings...Bohemia Lite...........Thanks for watching...........I hear Ya alright (as, I use to have, and also worked on, a 1972 Ford 351 Cleveland V-8, with a Model 2100...2-Barrel carburetor on it, which is probably, very close lookin', to your, probably being, a Model 2150...2-Barrel carburetor, as far as, I might know)...........It's not so much, the Carburetor's fault, that you seem to be having, some, shall we say, "restricted access", to one, (or, in some cases, both) Idle mixture screws, and is usually, because of, all of the other parts & pieces, that might be Mounted..."right-in-front"...of the Carburetor (correct...???)...........Here are a few ways, that you'll probably be able, to get at, that, not so easy, to get at & adjust, idle mixture screw............There use to be, a, shall we say, "special", idle mixture screw, adjusting tool, that kinda looked like, a fairly long, small diameter "spring", that had, a screw driver-like handle, on one end of it, and, on the other end (of that long spring), had the proper, type & shape of "tip" (or, call it a "bit"), that would match-up, with the idle mixture screw's head (as in, a slot, for a plain tip screwdriver, to fit into, as an example), that needed to be turned/adjusted............You can also, buy or make, a fairly long, small diameter, and, long enough screwdriver, to reach in there, providing that, it's able to make it in there, in a straight line, or, can be a bit off to the side, as well, seeing as how, an idle mixture screw, usually doesn't take much force at all, to make it turn...........Might even use, a long enough, piece of plastic tubing (fish aquarium pump's, neoprene/clear tubing), that fits snugly, over the idle mixture screw's "head", as, it can bend quite easily, and might be able to, get around, something, that is slightly in the way, possibly...........Be very "gentle", when-ever turning, an idle mixture screw, all the way in, until it stops, b-cuz, it will usually have, a fairly long, quite small (in size), pointed "taper" (angle), on the end of it, so it doesn't get...Damaged...!!!...........No-matter, what "tool", you might use, to make the adjustment on the Carburetor..."Make Sure"...!!!...that your hands, and arms..."Don't come in Contact"...with any..."Spinning, or Hot engine Parts"...so you don't get hurt...!!!..........Good luck, and.......till next time.......Be (extra) Safe, take care, and have a good one.
Mixture screw was set with the engine off counter clockwise 3 turns. What about the idle speed screw, Is there a baseline for idle screw too?
Greetings...curtis sanchez...........Thanks for watching..........That 3 turns out (counter-clockwise), from just being lightly seated (as in, being fully closed and turned clockwise), is basically, just a rough setting, so that, the engine will start up and run alright, until the, shall we say, "fine adjustments" are made, when the engine becomes fully warmed up, to operating temperature (and also, with the choke plate, being fully open as well).........Whether it happens to be, the "rough" setting, for either, the "idle mixture screw"...or...the "idle speed screw", then, these so called rough settings, are usually called, "bench settings" (as in, on the work bench)...........Each engine and carburetor combination, will usually have its own "specification", as it applies to, the "curb" idle speed (curb idle speed, kinda means, the curb, at the side of the street, basically, and, the vehicle not moving at all, just as it would be, "idling", at a red light or stop sign)..........The adjustments are really fussy, if the vehicle has to be smog/emissions tested, and, not so much, if the vehicle "does not" have to be smog tested..........Have a look in your engine compartment, or, under the hood, for a sticker or label, that might have the (curb) idle "speed" specification, printed on it, and there might even be, the way in which to do it, as in, procedure..........Sometimes, there might be some vacuum hoses, that might have to be removed and plugged, and/or, wiring disconnected possibly...........Here are some settings, that I've used in the past..........For an automatic transmission car, the idle speed, was about 700 RPM's in Park, and would drop down to, a curb idle speed, of about, 600 RPM's, when the automatic transmission was placed in Drive, while the brake pedal was pushed down, and also, while the engine was fully warmed up to operating temperature (choke, fully off)..........The curb idle speed, can't be set too fast (RPM's, too high), for an automatic transmission vehicle, or, the vehicle, will tend to "creep" along (forward), way too fast, as soon as you release the brake pedal...!!! (same thing happens, if the choke hasn't reduced, the fast idle speed enough, while placing the automatic transmission in Drive...!!!)...........I have also seen, a "standard transmission" (with a clutch pedal) car, that had a curb idle speed, of 850 RPM's, while the standard transmission was in neutral, or, while having the clutch pedal depressed, and, engine fully warmed up, which was that high, for smog reasons...........Never, stand in front of, an automatic transmission vehicle, while it is in Drive, or, any other gear, because, you, or someone else, might get run over...!!!..........I usually, set the Idle speed screw, with the "emergency brake on", vehicle on level ground, while in "Park", at about, 100 RPM's higher than, the idle speed, that I want to have, when the automatic transmission is in Drive, while I also have the brake pedal pressed down, for "Safety" reasons...!!! (oh, and, engine fully warmed up, as well)..........If the vehicle needs to be smog tested, then, you'll have to find the specified (curb) idle speed, and set it to that...........Sometimes, there might be, what is called, a "lean drop" specification, for setting the idle mixture screws, that might be printed, on that label or sticker, that I had mentioned earlier..........The instructions (sheet of paper), that is usually found, in a carburetor rebuild kit, will usually have, quite a few specifications on it, as well as, the way to do the adjustments or settings............A Haynes aftermarket manual, will also, help a lot, with plenty of information too............If Ya need any more help at all, then, just let me know, about, your vehicle's...year...make...model...engine size and number of cylinders, automatic or standard transmission, and also, if the vehicle has to be "smog tested", or not...???............Good luck, and.......till next time.......Be Safe, take care, and have a good one.
Can you adjust the mixture using a vacuum gauge? The highest vacuum is where you want it?
richard collis Greetings richard collis....Thanks for watching, and, for Your questions as well...............................If, and I say If, the Vehicle in question's..."Engine"...is not subjected to, and required to "Pass", something like a "Smog/Emissions Test", and is, something along the lines of, that, of being something like...oh, let's say, using an Early 1960's...Chevy...Dodge...or Ford...Car or Truck, for Example, and also, being as "Basic" as can be, pretty much meaning, having a Carburetor, sitting on top of the intake manifold, and, not having much, in that way of "Smog Controls/Gadgets", and, "No-Computer-what-so-ever", then, as I see it, the Odds are very good, that, a Person can use, either, a..."Vacuum Gauge"...or, a..."Tachometer"...to..."Set"...the..."Idle Mixture"...and, the..."(Curb) Idle Speed", well, on a good day, that is.......................The way, that I would probably, shall we say "Set-Up", the "Idle Mixture" and "(Curb) Idle Speed" (the Engine's "Curb Idle Speed" in "RPM's", is pretty much, just that, and, as I see it, just means, what the Engine's "Idle Speed", happens to be "Set-At", while the Vehicle's Engine, is Fully Warmed-Up, and, the Vehicle, is just "Idling" near the "Curb", and Not Moving at all)..............................The "First Thing", that has to be "Determined", is, the Engine's "Curb Idle Speed" ("Automatic Transmission" equipped Vehicles, are usually Specified in "Drive", but not always, while "Standard/Manual Transmission equipped Vehicles, with the "Clutch Pedal", are usually Specified, in "Neutral/Not in Gear"), and hopefully, the Vehicle's Manufacturer has a Specification for that..................For "Safety" reasons, I always make Carburetor Adjustments, with the Engine Running...Fully Warmed-Up...Choke Off...while the Automatic Transmission is placed in "PARK", so the Vehicle "Does Not Decide to Take-Off/Move"...!!!...along with having the...Vehicle on Level Ground...Parking/Emergency Brake On...Wheel/Tire Chalks (lumber/bricks), and, have a Fire Extinguisher, with-in easy reach, just in case, oh, and, also, have the Vehicle "Outside", or, if, the Vehicle, is in a Garage, have All of the Garage Doors, that lead to the Outside/Fresh Air, "Open", as, Engine Exhaust Fumes are "Deadly"...!!!........................Here is an "Example Only", and I'm only using this example, to help People out, and hopefully, help those very same People, some-what, in, understanding, what is usually goin-on, when-ever I happen to be making a "Basic", Low Compression, Older, Factory Stock Engine's, "Idle Mixture and Curb Idle Speed", Carburetor "Adjustments"...................Once the Engine is "Fully Warmed Up to Operating Temperature"...and, the..."Choke is Fully Off"...as well, and, oh, let's say, that, the Vehicle happens to have an "Automatic Transmission", and the Hypothetical/Imaginary, "Curb Idle Speed" needs to be, for Example (only!), set at "650 RPM's (Crankshaft Revolutions Per Minute), while the Automatic Transmission is in "DRIVE" (please note, when-ever the Automatic Transmission is placed in "DRIVE", have Your Foot on the Brake Pedal...!!!)...but, like I was sayin', I make the Carburetor "Idle Mixture & Curb Idle Speed Adjustments", while the Automatic Transmission is in "PARK" (for "Safety" reasons)...then, once I'm satisfied, with the "Idle Mixture Settings", that I've made, my "Curb Idle Speed/Screw", is "Set", while the Automatic Transmission is in "PARK" (always remember Safety...!!!), to about "100 RPM's Over", that "In DRIVE, Curb Idle Speed", of "650 RPM's" while the Auto-Trans is in "PARK", meaning that, while in "PARK", I Set the "(Curb) Idle Speed Screw or Solenoid", as the case may be, to "750 RPM's" (650 RPM's + 100 RPM's = 750 RPM's), then, once the Auto-Trans is placed in "DRIVE", and, having a "Foot on the Brake Pedal", the Engine "RPM's" will usually "Drop", about "100 RPM's", give or take some "RPM's", and, if it's more or less then, that "650 RPM's (in "DRIVE"), then, in order, for me, to have that (Imaginary) Engine, end up with, a "(Curb) Idle Speed", of "650 RPM's in DRIVE", I place the Auto-Trans Back in "PARK", and Adjust the Engine RPM"s "Up or Down", with the "(Curb) Idle Speed Screw" (or Solenoid?), as required, and, it might take a few tries, to get it just right, but, as I see it, it really..."Is a Safe Way to Do it"...!!!..............................Yeah, I know, I know, what about actually "Setting the Carburetor's"..."Idle Mixture Adjustment Screws"...???...lol..............Well, it kinda worked out, the way that it did, more or less, so there would be a some-what Basic Understanding, at, oh, I guess I could say, to maybe, just get, the "Whole Picture", and to more or less, see what we are up against, that's all...............................Now then, about using a "Vacuum Gauge"...or, a..."Tachometer" (that measures the Engine's Crankshaft RPM's), and...by Using Either "Method" (Vacuum Gauge, or a Tachometer), as I see it, the "End Result", should be, about the same.........................I'll use that "750 RPM's" (in PARK), for this Example, on, something like a very Basic, Older, Rochester 2 or 4 barrel Carburetor................It's really, just a matter, of, getting "Both Idle Mixture Screws"..."Set"...at the...some-what, "Leanest, acceptable, Air/Fuel Ratio"...having the Engine, "Idling in PARK", (Smoothly), at that "750 RPM's" (in PARK)...(Example Only!)...while also, seeing the "Highest Vacuum Reading", showing on the "Vacuum Gauge", and also, having, "Both Idle Mixture Screws", "Turned Out", from being lightly seated in the Carburetor, about the "Same Amount", of "Turns, and Partial Turns", as in, having a, shall we say, reasonably, "Balanced" Adjustment, between, the 2 Idle Mixture Screws (like I was explaining in this UA-cam Video of mine, and using some chalk, on the Idle Mixture Screws, as I was showing) and, there can be the odd time, where-by, having, the "2 Idle Mixture Screws"..."Not Set Reasonably the Same", as in, Turns & Partial Turns out, from being lightly seated, that is...has been know to, have a Carburetor, that Runs, not so good, and maybe even cause the Engine to, some-what have, a, shall we say, "Hesitating Personality", perhaps...........................Same thing, pretty much happens, if using a "Tachometer", and not a "Vacuum Gauge", as well, only, the Tachometer would be showing, the "Changes in, Engine, Crankshaft RPM's", while the "Vacuum Gauge", would be showing/reading, the Engine's "Vacuum Level" (usually taken Below the base of the carburetor, and, inside the Intake Manifold)...expressed in..."Hg, or Inches of Mercury".....................................................................The Word "Vacuum", as it applies to these Gasoline Engines, can be confusing, and, the way that I like to look at the word Engine "Vacuum", is, I, just think of, the words..."Pressure Differential"...or..."Differences in Pressure", as in, the..."Difference in Pressure"..."Between"...the..."Air/Atmosphere, just Outside the Carburetor/Air Filter Housing...and the..."Air Pressure/Vacuum"...that is..."Just Below the Carburetor's Base, and Inside the Intake Manifold"......................Funny thing though, I've always thought of, Buying a "Vacuum Gauge", after all of these Years, and, I "Still Don't have One"...!!!...Say What"...???...lol...Yes-Sir-ee-Bob, all, I've ever used, is, one of my Trusty ole "Automotive Specific Tachometer Equipped Multi-Meters", and, had some pretty good luck (might even be, some skill, somewhere in there, as well...???...lol), in, being able to make the required Carburetor Adjustments, to get those damn Vehicles, through, the "Smog Test"...and maybe..."Even Pass"...!!! (well, at least most of the time, that is...lol)..............................Basically, just using a "Vacuum Gauge", to "Set" the Carburetor's "Idle Mixture", with the "Idle Mixture Screws", would, pretty much, be Done the "Same-Way", as I've done in this particular UA-cam Video of mine, but, with a few Exceptions.............................Instead of, Adjusting the "Idle Mixture Screws", to get the "Highest RPM's" (that's "Just Before", I proceeded to do, the "Lean Drop/Method", that is), using a "Tachometer", like I've done, in this Video, then, if a person, were to Use a "Vacuum Gauge", then, just aim for, the "Highest Hg/Inches of Mercury", while Adjusting the, 2 Idle Mixture Screws, about the same Turns/Partial Turns, Out, from being lightly seated (always, try to remember the word "Balance" while making Adjustments, to Both/or Either, Idle Mixture Screws), while, also, keeping the Engine "RPM's at the Specified (or chosen) "RPM's".........................If using a "Vacuum Gauge", just follow this Video of mine, up to the "Point"..."Just Before"...I start "Doing the Lean Drop, in RPM's", with the "Tachometer", but, "Instead", this time, Using a "Vacuum Gauge", to get the "Highest Hg/Inches of Mercury", showing on the "Vacuum Gauge", at the Specified/or Chosen RPM's, as that's essentially, what to do, but only "if", the Vehicle in question, Does Not have to be Smog/Emissions Tested"...!!! (just so, You and Others are aware, just in case...???)...............................Try to find, what is known, as a "V.E,C.I." Label or Sticker, that might, just be Stuck, inside Your Vehicle's Engine Compartment, somewhere, as that, my Friend, will usually, have some very Important and beneficial "Information" on it, that, pertains to, and in some, if not most cases, might just have, the Idle Mixture & Curb Idle Speed, "Specifications", and/or, "Setting Procedure/s" on it, as well, hopefully...........................Another Option, that should be available, and, to be even more Accurate, as to the Final Carburetor Adjustments, can be done, by a Vehicle "Fix-Em-Up-Establishment" (aka, car or truck Repair Shop), for a Fee/Charge, that has a "Tail Pipe Probe", that is connected to a Hc/Co (Hydrocarbon/Carbon Monoxide) Meter, where, the Technician/Mechanic, will be able to "Fine/Tune Adjust" the Carburetor, "Based on the Exhaust Emissions", coming out, of the Vehicle's Tail Pipe/s................................I hope, all of what, You have read here, helps You out some-what, and...Till next time............Be Safe, take care, and have a good one.
Thanks for taking the time to make this video. I have a 2 barrel Autolite 2100 carb and an automatic. Do I need to plug the vacuum advanced like if I was checking timing or leave vacuum advanced intact? Also with the automatic, you do recommend adjusting while car is in drive or can this be done in park?
Greetings Quang Bui....You are welcome, and thanks for Your comment/questions....I have spent quite a bit of time, working on a Motorcraft 2100 Carburetor, and, I'm pretty sure that it's the same as the Autolite 2100, with both of them being 2 Barrel carburetors....I have no idea, as to which Vehicle and Engine that Your 2100 2 Barrel Carburetor is mounted on...and...Do You have to have Your Vehicle "Smog" (aka, Emissions) Tested?...if so, then, You have to be a bit more "Precise" in Your Idle Mixture and Idle Speed Screw/s "Settings!"
If Your Engine is Stock, without any Modifications, then, the best thing to do, is to have a look around Your Vehicles Engine Compartment (under the Hood), and see if You can find a V.E.C.I. (Vehicle Emission Control Information) Label/Sticker, as that Label/Sticker, usually has the required Information, on how to "Set-Up/Adjust" Your Autolite 2100 Carburetor for Smog/Emission Testing.
In the event, that You are unable to find the required Information, then, here is what I would usually do, to Adjust the "2" Idle Mixture Screws, and the Curb Idle Solenoid or Screw...
The Engine has to be Fully warmed up, with the Choke completely Off and Open.
Air Cleaner Housing, and Air Filter "Installed".
Air Conditioning, Heater Blower Motor, etc. Turned "Off".
I usually do a "Lean Drop" of, no more then "100 RPM's", from the Fastest Idle Speed, that I can get with the "2" Idle Mixture Screws.
Some of the V.E.C.I. Label/Stickers that I have seen, can have Different Lean Drop RPM Settings, and some, might even be around 40 RPM's, depending on the Vehicle Manufacturer, Engine and Carburetor, that was Originally Installed.
You just have to remember, Not to let the Engine Idle Speed get Too High, as that can cause the Mechanical and Vacuum Advance to Add "Unwanted" Ignition Timing, that usually "Alters" the Speed/RPM's of the Engine.
I usually do the "2" Idle Mixture Screw Settings, while the Vehicle is in "Park" (automatic transmission), for Safety reasons.
Vehicle on Level ground...Automatic Transmission in "Park"...Parking Brake On...Wheel/Tire Chalks (aka, Bricks, Lumber, etc.) to keep the vehicle from Moving!
The Vacuum Advance (rubber) Hose, should be "Plugged", so as to make certain, that, the Vacuum Advance "Is Not" causing an RPM Change, due to Advancing the Ignition Timing, which will Mess-Up the Lean Drop, and Idle Speed Settings.
Most Stock Ignition Systems, on the older carburetor equipped engines, as far as I know, Don't usually Start Advancing the Ignition Timing, until, the Engine RPM"s Exceed about 1000 RPM's, but, I will bet, that there are exceptions!
Once the Engine is Fully Warmed Up to Operating Temperature, Set the Idle "Speed" "Solenoid or Screw" to "800 RPM's", then Adjust Both Idle Mixture Screws, a little at a time, to get the Fastest Idle Speed, showing on Your Tachometer, but, make sure that if the Engine RPM's start to go Higher then that "800 RPM"s", then Reduce the Idle Speed back to that "800 RPM's", with the Idle Speed "Solenoid or Screw", and re-adjust those "2 Idle Mixture Screws", to get the Highest RPM's, while Not going over that "800 RPM's", by very much.
Once You have the Highest RPM's that You can get, with the "2 Idle Mixture Screws", Re-Adjust the Idle "Speed" Solenoid or Screw, to get Exactly "800 RPM's" showing on the Tachometer.
Then, put a Chalk Mark, or other mark, on the "2 Idle Mixture Screws", at the 12-O-Clock (aka, closest to the Sky) position.
Then, it's just a matter of, Turning "In" (Clockwise), the "2" Idle Mixture Screws "EQUALLY" (Same Amount for each Idle Mixture Screw), each one a little at a time, turning the Left one a bit, then the Right one a bit, and go back and forth between the 2, Until the Tachometer is showing Exactly "700 RPM's", and "Both" Chalk Marks are Pointing in, Exactly the same Direction, as in the "O-Clock" position!
Once the "Lean drop" Procedure is done with the "2 Idle Mixture Screws", then just leave them "Set" at that Position!
Once that is done, making sure that You can see Your Tachometer while sitting in the Driver Seat, put Your Foot on the Brake, and put the Automatic Transmission Lever in "Drive", and see what RPM's the Engine is Idling at...
If the Engine "Idle Speed", while in "Drive" with Your Foot on the Brake, is either too High or too Low, then, put the Transmission, back in "Park", and Adjust the Curb Idle "Speed" Solenoid or Screw to Increase or Decrease the Engine RPM's, then, Foot on the Brake, and put the Transmission in "Drive" again, to see what the Engine RPM's are at.
Repeat the "Idle Speed" Solenoid or Screw Adjustment, if needed, while the Transmission is in "Park", so the Vehicle Won't Move! (for Safety reasons!).
If Your Vehicle "Does Not" have to be Smog/Emission Tested, then, You can usually, just Adjust the "2 Idle Mixture Screws" for the Fastest RPM's, "Without" having to do the "100 RPM Lean Drop" Procedure, but, Your Vehicles Gas Mileage/Kilometer-age might not be as good, especially while Your Engine is Idling at a Stop Sign or Red Light.
Your Engine has to be "Tuned-Up", and the Maintenance "Items" must be up to date, to give Your Engine the Best Chance, at running the Best that it's able to.
If You need any help at all, let me know, all that You can, about Your Vehicle and Engine, or, I will still, be going on a...
..."Wild Goose Chase!!!"...lol.
Good Luck...
Be Safe, take care, and have a good one.
RockysRoadshow Thank you for the detailed written instructions. Sorry for not entering my car's info. No, I do not need to pass smog because it's a 1969 Mustang 302 (probably orig). In California I believe any car older than 1975 do not need to be smogged. Air cleaner, fuel filter, plugs, plug wires, oil, electronic ignition have been recently changed. Carb have been replaced/rebuilt a few times since I've owned it for less than a year due to numerous issues but seems to be running well now except for fumes. The reason I want to apply you method is when I have the windows rolled down or the top down and stop at a stop sign/light, seems like there's a back draft and the gas smell would rush pass the car.
Thank you again for passing along your wealth of knowledge to myself and others!
Quang Bui Greetings Quang Bui....Exhaust "Fumes" You say?...Been there, Seen that...and..."Fixed" that too...!!!...lol....Before I start tellin' You, about the Many Things, that can cause, what appears to be a "Rich" Air/Fuel Ratio, that Your Autolite 2100 Carburetor just might be Feeding Your Engine, I will mention the following....The Gasoline that is being sold these days, usually has a certain "%-age" (aka, Percentage) of "Ethanol" (aka, Alcohol) added to the Gasoline....This Percentage of Ethanol in the Gasoline can vary somewhat, depending on where You live....The Higher the Percentage (or amount) of Ethanol in the Gasoline, the "Leaner" the Air/Fuel Ratio, the Carburetor will be administering (aka, Feeding) Your Engine.
The more Ethanol that is in the Gasoline, the More that problems will usually occur, not only causing a "Lean" running Carburetor/Engine, but this Ethanol, as I have been reading, can cause Fuel System Parts, including the Carburetor itself, to start to Corrode, and cause deterioration of rubber-like parts as well.
When You (or someone else) Rebuilt Your 2100 Carburetor, did You (or they) Install a "New" Float?
If it's made of "Brass", which I highly doubt, then the Float is usually made out of a Material called "Nitrophyl" (looks like black plastic), and this stuff, is prone to acting like a "Sponge", and some of them, over a period of time, can, and will "Absorb" Gasoline, causing the Float to start to "Sinking" somewhat.
When these Nitrophyl Floats start Sinking, the "Wet" Fuel Level in the Carburetor Float Bowl will usually become "Higher" then wanted in the Float Bowl, and will usually cause an Overly "Rich" (Air/Fuel) Ratio, and, could be the cause, of all of those excessive Exhaust "Fumes" that You had mentioned.
Some People, Install a Float, be it New or Used "Without" Checking and Setting it Properly, to the Proper "Specification", which, as I see it, will make for a "Not-So-Fun" (and Poorly) Running Carburetor! (could cause a too "Lean" or too "Rich" Air/Fuel Ratio).
(Please, don't use the following, as these Measurements, only Applied to one of the Motorcraft 2100 Carburetors that I rebuilt a while back...."Dry" Float Setting was 3/8" from the Top of the Float Bowl, to the Top of the Float, while applying light pressure to the Needle/Seat assembly, and, the "Wet" Fuel Level in the Float Bowl was 3/4", as I recall).
Make sure, that Your, I hope "New" Float, is "Set" to the Proper "Specification", that You can find, in a Factory Service Manual, or, on the Rebuild Kit's "Instruction Sheet/Paper", for Your Exact Vehicle and Engine.
Make sure, that Your 2100's Choke, as in, the Fast Idle Cam/Screw, Linkage, and that the Choke Plate is Fully Vertical (aka, Fully Open), when Your Engine is Fully warmed-up to Operating Temperature, or, it may cause..."Fume-City!"...lol.
Sometimes (I'm thinkin'), if Your Engine may have "Back-Fired" at some point in time, that has been known, to sometimes "Rupture" the "Power Valve" Diaphragm! (some call it an Economy Valve), which, as I recall, makes for a "Very Very Rich" (Air/Fuel Ratio), and, if that be the case, that could very well be, what's causing those "Fumes" that You are experiencing.
The Power Valve is Located "Underneath" the carburetor Float Bowl (if memory serves me right, that is).
Also, if someone "Messed-up", and put the "Wrong" Rating of Power Valve, in the Rebuild Kit, or, if Your Engine has an Aggressive Aftermarket Performance Camshaft installed in it, that can cause a very "Low Vacuum Signal", while having the "Stock" Rated Power valve Installed in the 2100 Carburetor, that "Stock" Power Valve will usually be Adding In Fuel, when it's Not Supposed to...!!!
It could be, that, Your Fuel Pump, is putting out, Too Much Fuel Pressure, which will usually "Over-Power" the Floats "Ability" to Close the Needle/Seat Assembly, which in turn, will cause a "Too High" Wet Fuel Level, in Your 2100's Float Bowl, and again I say...Fume-City!...lol.
Could even be Dirt/Crud that has lodged in between Your Needle and Seat, which in turn, will cause that very unwanted Too "High" of a "Wet" Fuel Level in Your 2100's Float Bowl.
Seeing as how you are so very Fortunate, as in...Not Having to have Your Vehicle Smog/Emission Tested, You Don't have to bother with that "Lean Drop" Idle Mixture Screw Setting.
Just, set the "2" Idle Mixture Screws to the "Fastest RPM's", and, the rest of the Information that You should need, is already in my Previous Comment/Reply to You.
Did You "Gap" Your Spark Plugs, before You Installed them, in Your Engine???
Electronic Ignition, You say???
I'm thinkin', that Your Engine's "Ignition" has been "Upgraded"...
As far as I recall, a 1969 Ford, had a "Points and Condenser" Type of Distributor installed by the Factory.
The Only way, that I can get close enough, to figuring out, what Your "Fume" Problem is, is to let me Know, "Any and All" Modifications or Upgrades, that are Over and Above, that of the "Factory Installed" Parts, and, if there are "Any" Running/Performance Issues as well.
So then, perhaps "Check" all of the Things, that I have mentioned above, and if You like, let me know, how You're makin' out.
Be Safe, take care, and have a good one.
RockysRoadshow
Wow! Thanks again to take the time out to write a thorough response! Truly appreciate your time.
I've done a few things with the Mustang since I've owned it. Purchased a rebuilt carb, had my original carb rebuilt, then rebuilt both myself after that. I had one that had a brass float and one that had the new nytrophyl. Not sure which one is in my car right now. When I rebuilt both carbs, I did not do anything with the choke since they were already rebuilt and new. I did replace the rest of the items that were in the kits; seats, needles, check balls, gaskets, power valves, clean the lines,... I did check the floats according to the kits with the supplied ruler. I also replaced the fuel filter with motorcraft filter, added a second filter before the mechanical fuel pump, replaced all rubber hoses with EFI hoses, replaced the fuel tank. I adjusted the choke so that when you first step on the gas pedal before starting, the plate almost closes and then open fully when warmed up. Then when I step on the gas, the fast idle disengage and curb idle takes over. Also replaced the electric choke with hot air choke since the electric choke opened the plate too quickly by using a choke stove. Seems to take a little longer to fully open which is what I was looking for.
Yes, ethanol in the gas is the only thing I can buy here. There's only a few places in Southern California that sells ethanol free gas and it's at least 50 miles away. The way my car sucks up gas, it'll cost me half a tank to go fill a tank.
As far as my engine is concerned, I don't have any info on it other than it's a 302. Don't know if it was ever rebuilt or any modifications were made to it. The person I bought it from inherited from his dad when he passed away so he didn't know the history.
I installed the Pertronix Ignitor I so I don't have to deal with points/condensers. Seems to be OK so far.
Will try to find some time to apply your techniques when I have a chance. Traveling and then planning to upgrade my front suspensions over the 4th weekend. These old cars can sure suck up you money fast but they are fun to drive.
Thanks again RockysRoadshow!
Quang Bui
Greetings Quang Bui....Your Engine's Spark Plugs will usually be a pretty good "Indicator", as it applies to, how "Rich" or how "Lean" of an "Air/Fuel Ratio" that Your 2100 Carburetor is Feeding Your Engine....A good place to get started, would be the following...
With Your Engine "Cold", Remove "1" Spark Plug at a time, so You don't run the Risk of placing the spark plug "Wires" on the "Wrong" Spark Plugs!....I have a...How to Read Spark Plugs...Video, on my UA-cam Channel...RockysRoadshow...enjoy.
Also, have a look-see at the other Videos that I have Uploaded, as I'm pretty sure, that there should be some Information, that might just help You out, somewhat.
If You do, Remove Your Engines Spark Plugs, "Record" (aka, write down on paper), everything that You notice, about...Color...Deposits...Carbon build-up...and how much the "Wear Amount" (aka, Gap) is, on both, the Inner Electrode, and the Outer Electrode, and also, make sure that You Record "Which Cylinder", that "Each" Spark Plug, came out of...!!!
Also, "Check" (as in Measure) the Spark Plug "Gap".
If You care to, let me know, what You have Observed/Found-Out, as, those good ole Spark Plugs, really "Do" have a "Story" to tell...!!!
Be Safe, take care, and have a good one.
Thank for the great vidio presentation. I have a 59 cad with 4GS carb. There is big screw with the spring in the back of the carb facing towards the driverside. I beleive it calls, Idle speed bypass screw. How do i adjust that in relation with idel mixture screws and the curbe ide screw? When I crank the screw in, the rpm drops, and by unscrewing it, the rpm goes up.
Thanks for any advise.
59cadfins Greetings 59cadfins....You are welcome, and, thanks for Your comment/question, and for watching as well...................................................Before I get on with, what, information, that I will leave in this comment/reply to You, is, in order for me, to be able to help You out, to the best of my ability, would be, for You, to have a "Look", at the "Carburetor", that is "Installed"...on Top of Your Engine's Intake Manifold......................................................Please, let me know, the following.............The "Carburetors" (brand) Name (if one is showing)..."Any Numbers or Letters", that might be "Stamped" in/on, Your Carburetors "Exterior/Outside" (as in, Top...Front...Back...Left and Right Sides, and with the engine cold, and not running, You might have to use a Mirror, and a Flashlight, to See those Numbers/Letters, especially, if there happens to be any, on the Rear/Back of Your Carburetor...also, when using a Mirror, the Numbers/Letters might "Appear Backwards"...just sayin'), and also, if the Carburetor, to the best of Your knowledge, "Is" the "Original, Factory Installed" Carburetor, or, if it happens to be, something, other, then the "Original" Carburetor, as that my Friend, will help me a great deal, and also, make it, that much less, of a..."Wild Goose Chase"...that I might have to go on, as well.........................................................I had a look-see, at some pictures and information, pertaining to the Carburetor, that You were telling me about.........................................................I wasn't seeing much, in the way, of a..."4GS" Carb, as I was mostly seeing, a...."4GC" Carb, when I did the search on it............................................................Also, for the "1959 Year Model" of Your "Cad" (I remember, hearing them, being called "Caddy's...that be that), the Engine that came up in my search, was showing a..."390 Cubic Inch" (V-8)...is that Engine, the "One", that is Installed in Your "59", or, does there happen to be, a "Different" Engine in Your "59" these days...???..........................................................I didn't see, the "Big Screw, with the Spring" on it, Located, on the..."Rear of the Carb, facing the Driver's side"...but, what I was seeing, was a..."Big Brass-colored Screw, with a Spring"...Located..."Between"...the..."2 Idle Mixture Screws"...on the..."Front of the Carb".........................................................In some applications, there might..."Not Have Been"...what is commonly know, as a..."Curb Idle"...Adjustment Screw...for Adjusting the..."(Curb) Idle Speed"...of the Engine.............................................From what I saw, and kinda figured out, has me thinkin', that, that, shall we say..."Idle Air Bypass Adjustment Screw"...was being used, to..."Control the (Curb) Idle Speed", of the Engine, seeing as how, some of those Carburetors, back then, might..."Not Have Had"...a..."Curb Idle, Adjusting Screw"...Engineered/Manufactured/Installed...on them...!!!............................................................Perhaps, You can have a Look, for the..."Curb Idle Speed Adjusting Screw"...and here's what to be looking for......................................................."If", You happen to see an Adjustment Screw of sorts, that might be "Making Contact" with, what is commonly known as a "Fast Idle Cam" (that "Cam", is what "Raises" the Engine's Idle Speed, and positions the Choke Plate, when the Engine is Cold, to prevent it from stalling), then..."That's Not It"...unless, the Engineers/Designers, just might have had, that..."Single Adjustment Screw"..."Serving 2 Purposes"...at the..."Very Same Time"...!!! (aka, doing double duty, in the from of, both, the Fast Idle, and the Curb Idle as well, maybe?)..........................................The most common looking..."Curb Idle Speed, Adjustment Screw"...basically, just makes..."Contact With"...the..."Lever or Bracket"...that the..."Throttle/Gas Pedal"..."Rod" (or Cable?)...Actuates, that Controls, the, Throttle Plate/s (butterflies/throttle valves), Angle/Opening, depending on, just, how much Your Foot is Pressing on the Gas Pedal...........................................................................The Carburetor, that I was seeing in the search results, to me, looked, for the most part, just like a..."Carter AFB" (AFB = Aluminum Four Barrel, I think?) Carburetor, but, that was just a few Pictures, and I haven't a Clue, as to, "What", the Carburetor that You have there, actually Looks-Like...???........................................................."IF"...???...You Don't happen to "Find", a "Curb Idle Speed", Adjusting Screw, on Your Carburetor, then, it is quite possible, that, that "Big Screw, with the Spring", is perhaps, what the "Engineers/Designers", of Your particular Carburetor, probably used, to..."Control/Adjust"...the Engine's..."Curb Idle Speed"...especially, considering, the absence of, the, as I've mostly seen, and adjusted many times, the..."Curb Idle Speed Screw" (and in some cases, it was an electrical Solenoid), on, the Carburetors, that I've...Rebuilt/Set-up/Calibrated, and Adjusted........................................................."If", and I say, "IF", it turns out, that You end up, having to, actually "Use", that there..."Big Screw, with the Spring on it"...to...."Control"...the..."Speed"...at which Your Engine..."Idles" at, You "Should/Must", find out, what, Your Engine's..."(Curb) Idle Speed"..."Specifications" are, so, You have a much better chance, at getting it Right, the First time, hopefully.......................................................What I'm visualizing, is, it really boils down to a, shall we say..."Balancing Act"...where-as, the...(I'm thinkin')...."2 Idle Mixture Screws"...have to be..."Balanced", with the...shall we call it, an..."Idle Air Bypass Screw"...Adjustment Amount (aka, the Turns/Partial Turns Out, from being Lightly seated) perhaps, in order to have, a Carburetor (Yours, in this case), Idle Smoothly, and at the Specified (Curb) Idle Speed, as well as, having the..."Idle Mixture Screws"...Adjusted, as..."Lean" (air/fuel ratio-wise) as possible, but, "Not-so-Lean", that, the Engine, starts experiencing, what is known as, a..."Lean Miss-Fire", that by the way, from my previous experience, at times..."Can't be Detected"...Without, having a..."Smog/Emissions Test"...done, unless, the Engine, actually, starts..."Shaking"..to some extent, at (Curb) Idle Speed, that is..........................................................Before I go any further, with, how I would go about, making the Adjustment/Adjustments, with this particular..."Carburetor"...please, let me know, all that You are able to, about Your Engine and Carburetor, as, the More, that I actually Know, about, what I'm dealing with, the More, that I should be able, to help You out..................................................I sure like, what the "Designers", did back then, with those Car..."Tail-Fins"......kinda has me thinkin', that..."Airplanes and Jet Aircraft"...had..."A Lot to do with it"...!!!.....................................................Till next time.............Be Safe, take care, and have a good one.
RockysRoadshow Thank you for taking the time to respond to my question.I beleive this is the original carb on a 390 engine. The only ID I could find says, Rochester 4GS and 4jet. There is a curb idle speed adjusting screw where the throutle linkage is connected on the Dr. side. However, there is none for fast idle adjustment which is normally located under the choke on the passenger side. Or I might be wrong. The curb speed adjusting screw could be for fast idle cam adjustment and the big screw in the back could be for curb idle speed adjustement. I will try to send some pictures. I have never done sent pics before hopefully, I will figure it out.Let me tell how this started, the problem is the car would not start i had to use starting fluid so I knew the plunger was not working. Other than that the car was running perfect. So I removed the carb to get remanufactured. Once it was reinstalled the plunger was working fine the car starts up immediately. However, when i am stopped, when I accelerates the car hesitates. My research shows this is the accelerate pump issue. I know it has been replaced since it starts now. Is it lean or rich thats what I am trying to figure out. Thanks again
rodchester quadrojet carb. will not hold rpms, got any ideas what would cause that?
+Rick Smith....Greetings....Rick Smith....Thanks for watching.................You were sayin', about, Your Rochester Quadrajet 4-Barrel Carburetor..."Will Not Hold RPM's" (might not be the Carburetor...maybe...???)..................In order for me to narrow-down, what might be causing Your Engine's, lack of RPM's, then, if You can tell me, under what Engine Operating Conditions, does Your "Too Low RPM's" occur at, as in, is the...Engine...Cold...Hot...at Idle Speed...in Gear...in Park (automatic transmission)...at Cruising Speed...or what-ever it might be...???..................Also...the Vehicle's...Year...Make...Model...Engine Size/Liters/Cubic Inches...Automatic or Standard Transmission/with the clutch pedal...etc.........So then, please, Describe to me, the best that You're able to, about any Engine "Running Problems", that You are hoping to Fix, and..........till next time.........Be Safe, take care, and have a good one.
Can you show this with a 1964-66 rochester 2 barrel that would be on c10 1/2 ton Chevy pickups?
Karamelia Mitchell Greetings Karamelia Mitchell....Thanks for watching, and for Your comment/question as well............................Well...if I were to show show You, and Others as well, about how to Adjust the "Idle Mixture Screws"...and...the..."Idle Speed Screw"...on that..."1964-1966-Rochester 2 Barrel Carburetor"...that You had mentioned, then, what You would probably be Seeing, is, pretty much, like, what You, (and Others), have already Seen, in this very UA-cam Video of mine, with the exception, of the "2 Extra Secondary Barrels", that You saw, on this "Carter Thermoquad 4 Barrel Carburetor", that is.............................Generally speaking, on most "2 or 4-Barrel Rochester Carburetors, that I've Worked-On, the "Idle Mixture Screws"...are part of, the..."Primary, or Front"...Throttle Bores, and the Throttle Plates/Butterflies, that reside in "Them"..."Only"...and when "Adjusted"..."Only Affect...the..."Primary/Front Throttle Bores"...because of that particular "Idle Circuit Design" (the Secondary Throttle Plates/Butterflies, are usually Closed, on the Rochester "Quadrajet" 4 Barrel Carburetor, at Idle Speed).....................................Most, shall we say..."Old School"..."North American"..."Rochester 2-Barrel and 4 Barrel Carburetors" (well, depending on, just "What Year" we are talkin' about, some, go/went by the Name/Description, of...the Rochester "DualJet" 2-Barrel Carburetor...and the Rochester "Quadrajet" 4-Barrel Carburetor)...and, quite a few "Other Carburetor Manufacturers", that have a "Similar Looking Design", and having either..."2-Barrels" or "4-Barrels"...along with..."2 Idle Mixture Screws" as well, will, as I see it..."Pretty Much be Adjusted the Same"...but, and I say But...there are "Exceptions"...!!! (almost like Everything in Life...!!!...lol).............................What I'm getting at here, is...Does the Vehicle, and Its Engine..."Need to Pass a Smog/Emissions Test"...???...............as, that is, what will usually..."Up-Set-the-Apple-Cart"...if a "Carburetor" (and a Host of Other Things), are..."Not, Set-Up"...to..."Satisfy"...that there..."Smog-Sniffin' Bandit"...at, that there..."Smog-Sniffin', Vehicle's Engine, Smog Testing Establishment"..."Yee-Haw"...but, I only be Sayin' that, If-in, I Git, that thar, "Pass" (word") "Stamped", or was it "Printed", on that thar..."Smog Paper", that They give You, after, Takin' Yur "Money"...lol...........(Ok, stop Laff-in, so-zzz, we can Continue....Thank-You...lol).....................................Time to ask You a few things now.............................Does Your "C-10-1/2 Ton-Pick-Em-Up-Truck", have to be..."Smog/Emissions Tested"...???..................................In order for Me, to Not, be Going on a "Wild-Goose-Chase", it would be very beneficial, if You would, so kindly, have a look-see, at Your "Carburetor", and perhaps, tell me the following............................"Name" on "it" (aka, Rochester or...???).................Any Identifying "Numbers, and/or Letters/Words", Cast into/onto, the Carburetor, or, maybe "it" has, something along the lines, of a Metal "Tag", perhaps...oh, and also, the "Year" of Your "Pick-Em-Up-Truck"...???.................................Hey, just so You know, most of what You are Seeing and Hearing, in these UA-cam Videos of mine, are just, some, of the "Many Hobbies", that I'm, shall we say..."In-To".................................Well now, You see my Friend, the More, that You're able to tell me, about the "Patient" (aka, Your Carburetor), the More, I'll be able to help You out....Thanks-ah-Bunch...................Till next time.................Be Safe, take care, and have a good one.
I see many older carb vehicles running far to rich, black smoke and gas fumes! Proper air fuel mixture is far better for more power smooth running, keeps oil cleaner as well. My 72. Nova 350 two barrel Rochester runs to near perfect state of tune!
My 51 Chevy 1/2ton P.U. Rochester 216c.u. one barrel does as well!
Greetings...Bill Bright...........Thanks for watching............It's good to hear, that Your 1972 Chevy Nova, is running, good as a Swiss Watch (so to speak).........(I like the Nova, and, I use to ride along with a Friend, while he was driving his Mom's blue 1971 [I think?] Nova 4-door, that had a 250 cubic inch inline 6-cylinder engine under the hood, way back when)...............Lem-me-see-now...a 1972 Chevy V-8, would probably have a Points and Condenser, type of Distributor in/on the engine, unless "it" was Changed/Upgraded to something else............If You're still using the Points and Condenser, type of Distributor, then, I hope, that, the Points Gap/Dwell, is kept at that, about 30 Degrees Dwell specification, cuz, as the Points Gap Changes, (due to, arcing at the points, as well as, rubbing block wear), then, as a result, the Dwell, "and", the Initial (base) ignition timing will Change, as the Mileage starts to accumulate, most times.............Yes-Sir-ee-Bob, the older engines, that didn't have, much in the way of Pollution control Devices, as well as, the usually, quite a bit Leaner Air/Fuel ratios, that those Smog/emission Carburetors were probably calibrated for, were, for the most part, more than likely, calibrated, for a slightly Richer Air/Fuel ratio, generally speaking, that is.............If You are putting Gasoline, that has, oh, about 10% Ethanol (alcohol), in its Blend, into Your Nova's gas tank, then, that alone, will probably be having the Affect, of a slightly Leaner Air/Fuel Ratio, as compared to, having the engine burning 100% Gasoline (without any Ethanol in it what-so-ever), cuz, gotta remember now, that, those older Carburetors, were probably Calibrated/Set-up with, 100% Gasoline, and probably before, those Gas-Pump-Bandits, started to Pump-out, that Gas-em-ah-Haul (that be, the Gasoline, that had Ethanol/alcohol added into its Blend).............Although, just about any Gasoline burnin' engine, will run very well, that, in itself, can't really tell You, what the Real, and Genuine, Smog/Emissions, that are actually exiting the exhaust pipe/s, unless, having the Vehicle Smog/Emissions Tested, at the (smog) Testing establishment, or equivalent, there-of..............Case in point...I had a 350 Chevy V-8, with a 4-mv Quadrajet, sitting on top of the intake manifold, and, I had to take it though the Smog Test, and, my very first time, at that............So, I thought it would be a good idea, to get those 2 Idle Mixture screws, Leaned out a bit, cuz, I had no idea, as to, where they were adjusted at.............I turned in/clockwise, those 2 idle mixture screws, to Lean-out the idle mixture, quite a bit, to the point, where I had them at the Leanest setting, while also, having that Chevy 350 V-8, Idling in gear, and almost as Smooth at Silk, at the very same time............Well, so much for, the Engine sure Runs really well, cuz, after going through the Smog Test, "it" Failed, the (while) idling in gear, part of the smog test...!!! (oh no...!!!...lol)..............Well, it turned out to be, that, I went Too Lean (air/fuel mixture), when I adjusted those 2 idle mixture screws, to the point where, that Too Lean of an idle mixture (adjustment), ended up causing, what is termed, a "Lean Misfire", where-by, that, Too Lean, of an air/fuel ratio/mixture, would-not Burn properly, and probably sent, some Un-Burned Gasoline, through the exhaust system, that didn't have, or required, a Cat/Catalytic Converter on it................The "HC" (Hydrocarbons) were at about 700 +, and the cut-off point, was a @ 500 PPM/Parts per million, as I recall.............Also, a Carburetor's Air/Fuel ratio (mixture) "Varies" as well, depending on, what the engine's Operating conditions are, at that particular moment..............Very Rich, when starting a Cold engine, on a very Cold day, due to the Choke being On (as Gasoline, will condense, on the inside runners, of the intake manifold, until it gets hot enough, as an example)..............Once the Engine, is at Operating temperature, then, it can idle, at about 14.7 to 1 air/fuel ratio, or, a bit Richer, if need be..............Same 14.7 to 1, while just Cruzin' along, at, not too fast of a speed, and some tuners, can easily get into the 15 to 1 air/fuel ratio, on a factory/stock, low compression ratio engine, to increase Fuel Economy..............Here's where it gets "Rich" again, cuz, when You go WOT/Wide Open Throttle...Pedal-to-the-Metal...then, it'll probably be about 12.5 to 1 air/fuel ratio, there-abouts, as an example............Something like a Dirty Air "Filter", can kinda act, some-what like the Choke does, as in, in Restricts, the amount of Air, that gets into the Carburetor, and then, the result usually is, that, More Gasoline, gets sucked into the Carburetor, along with Less Air, which will usually, cause the Air/Fuel Ratio/mixture, to become "Richer", than it needs to be, and then, Fuel Economy will drop/become worse, as a result, and.......till next time........Be Safe, take care, and have a good one.
Greetings...Bill Bright............Nice to hear, that Your 1951 Chevy Pick-em-up-Truck is behaving itself as well...lol.............Ah yes, sure do like those times, where, Ya can spend more time Driving "them", rather than..."FIX-in"...the darn things...!!!...lol...but, then again, when the Engine Ain't Runnin'...Ya get Super Good "Gas Mileage" (as in none, what-so-ever...!!!)...lol...and.......till next time.......Be Safe, take care, and have a good one.
Tienes canal enespañol
i like the video but i would like doing it with automatic transsmition, because i just put a
quadrjet to my c10 and e had problems with the mecanics. how is not they veicles they dont care.my truck parked spend more gas than walking.i appreciate thank you
Greetings mco zpda....Thanks for your nice comment...and...I will give you some information on your "Other" Comment, that will perhaps help You get your "Quadrajet-4-Barrel-Carburetor" Adjusted close enough, in order to have your Vehicle, have a better chance at "Passing" the "Smog" (Emissions) Test....Be Safe, take care, and have a good one.
I WANT TO SEE WITH ROCHESTER QUADRAJET AND AUTOMATIC TRANS......THANKS
Greetings mco zpda....Thanks for your comment....I would like to let you know in advance, that, even if you manage to get your "4-Barrrel-Quadrajet" Adjusted properly for the "Smog/Emission" Test, that there are "Many" Other things that can cause your Vehicle to "Fail" (Not Pass) the Smog Test!....You said that Your Vehicle was a "C-10"...is it a "Pick-Up-Truck???...and...what "Year" is it???...what "Engine" Size???, and is it a "V-8"???....Can You See a Model Number on your Quadrajet Carburetor???....I actually "Did" get a "Quadrajet-4-Barrel" equipped "350-Cubic-Inch-V-8" to "Pass" the Smog/Emissions Test a few years in a row, but, the "NOX" (Nitrogen Oxide) Level was almost "Too High" (just Under the Maximum Allowable), because the Vehicle "Did-Not" have an "EGR" (Exhaust Gas Recirculation) "Valve" on the Intake Manifold, and also, my Vehicle "Did-Not" have a "3-Way" Catalytic Converter on it! (2-Way, also referred to as "Oxidation" Catalytic Converters "Will-Not" Reduce the "NOX" Emissions!).
If you can tell me as "Much" as you can, about your "C-10", then, I will have a much better chance at being able to help you out, with, getting your "C-10" to "Pass" the Smog/Emission Test.
Has your "Quadrajet" been "Rebuilt" Lately, because, if is very Old, it might not Work good enough to Pass the Smog/Emission Test, although, you can still try Adjusting it, and have it smog/emission tested, but, you will still have to pay them the Testing Fee, if it fails.
I still have some "Notes" on how I Adjusted my Quadrajet-4-Barrel-Carburetor that was on top of my 350 Cubic Inch (5.7 Litre) V-8 Engine, that was a very "Basic" (4-MV?) Model, that had the "Thermostatic Choke Coil" mounted separately , and it was mounted in a cavity in the intake manifold, as opposed to the "Choke" that was mounted "On" the side of the 4-Barrel-Quadrajet carburetor.
So then, if you care to, just let me know, all that you can, about your "C-10", so I don't end up, going on a...
..."WILD GOOSE CHASE!!!"...lol.
Till next time...
...Be Safe, take care, and have a good one.
is it true that the throttle plate should be totally closed to make the most vacuum?
or i have to follow manufacture inhg ?i want to tune my toyota 2 barrel idle and the idle vac reach 20inhg but the chart says 17 when i open the plate the idle is ruff. You explain how to adjust the carb but just with a base line with the idle mix screws but the idle speed screw whats its base line?
serchmarc Greetings serchmarc....Thanks for watching, and for Your questions as well............................................Each and every..."Vehicle"...usually has "Its" own "Needs", and, has to be "Adjusted/Set-Up", for..."What-Ever-the-Requirements-Happen-To-Be"...along the lines of, oh, let's say..."Does the Vehicle"...have to be..."Smog/Emissions Tested"...???...because, "If" it Does, the "Carburetor", has to have, the..."Adjustments/Set-Up"...to the..."Factory Specifications"...or..."If"..."It"..."Is Not"...there is a..."Strong Possibility"...that, when, that particular Vehicle...gets..."Tested"..."It"..."Will Not Pass the Smog/Emissions Test"...!!! (and yes, I've Experienced, what I was just sayin'...!!!...lol).........................................."If"...Your Vehicle has to be "Smog/Emissions Tested", the First thing, that You should be looking for, is what is usually called, a..."V.E.C.I. (Vehicle Emission Control Information) Label/Sticker"...that's usually found in the Vehicle's..."Engine Compartment"................Hopefully, You will find One, and the "Information", that You will See on It, should be..."Followed/Performed Very Closely"..."If"...Your Vehicle, Needs to..."Pass the Smog/Emissions Test"...that is.............Also, Your Vehicle has to be fairly "Stock", as in, little or No Modifications to It, and, just about "Every Thing", has to be in "Very Good Condition", and "Set-Up/Adjusted Properly", and some of those "Things", happen to be, the "Ignition System", the "Fuel System" (part of which, is the Carburetor), and, something like the "Emission/s System", that was "Installed" by the Factory/Manufacturer of Your Vehicle, when it was "Brand New"..................................................The Factory/Manufacturer, of each and every "Carburetor Equipped Vehicle", pretty much, has, or had, "Their Own Specifications & Methods of Tuning/Adjusting", and that's why, that "V.E.C.I Label/Sticker" (or, if You can Find the some-what "Same Information"), in something like, a "Factory (Chassis) Service Manual", then, as I see it, You will have a much better "Result", mostly, because, that will pretty much be, the "Way that the Engineers/Designers"..."Intended It, to Work/Perform"...just sayin'....................................................Now then, "If" Your Vehicle "Does-Not" have to be "Smog/Emissions Tested", then, what the, shall we say..."Old School"..."Mechanics/Hot-Rodders", pretty much did, as I see it, was to some-what, "Set-Up/Adjust", the "Idle Mixture Screws"...and the..."(Curb) Idle Speed Screw", to Obtain (get), the "Highest Vacuum Reading" (Hg...or...Inches of Mercury), that was Showing on the "Vacuum Gauge", when the Engine, was "Fully Warmed-Up, to Operating Temperature", and having the Engine, at the "Desired/Acceptable Idle Speed", all at the same time........................................................If the Vehicle, had an "Automatic Transmission", then, "Too Fast" of an "Idle Speed", would usually, make the Vehicle "Creep", as in, when the Brake Pedal was Released, the Vehicle would, shall we say..."Take Off" (Move) Too Much, and Faster then wanted, and that was Without Pushin' on the Gas Pedal...!!!...Yikes...!!!....................................You were sayin', about, having the Carburetor's "Throttle Plate"..."Totally Closed", to get the "Most Vacuum"...???..........Well, there are "Very Few Carburetors", that I have seen, where the "Throttle Plates" are "Totally Closed", while the Engine, was at "Idle Speed", and on Those Particular Carburetors, there was usually, a, shall we say, an, "Idle Air By-Pass Screw", for Adjusting the "Amount of Air", that was Allowed to "Flow" Through the Carburetor, while the Engine was at "Idle Speed"...................................................You see my Friend, on most of the "North American Vehicles", that had Factory Installed Carburetors, on their Engines, before "Fuel Injection" took over, well, They Worked, some-what, like the "Thermoquad Carburetor", that You saw, in this UA-cam Video of mine, as in, the "Primary" (Front) Throttle Plates", are "Slightly Open", while the Engine is at "Idle Speed", and, "Not Fully Closed" (Yes-Sir-ee-Bob, no Dedicated, Idle By-Pass Air Adjustment Screw on It, at all...!!!...lol).....................If You "Set the Idle Mixture Screws Too Rich", then, You might "Carbon Foul the Spark Plugs and Combustion Chambers" in Your Engine, as well as, get very Poor Gas Mileage/Kilometer-age, while at Idle Speed, while having the Vehicle standing still, at a Red Light or Stop Sign................................................................................If You "Set Your Idle Mixture Screws Too Lean", and, although, the Engine seems to be Idling alright, and quite smoothly, it could very well be, "Lean-Miss-Firing", and, on one Rochester Quadrajet 4-Barrel Carburetor, that I Adjusted the Idle Mixture & Speed Screws on, a number of years ago, by Ear (aka, Listening to), and even I couldn't tell if it was "Lean Miss-Firing" (Lean Miss-Firing, is when, the Carburetor's, Idle, Air/Fuel Ratio/Mixture, is a bit Too Lean, as in, Not Enough Gasoline in that particular, Idle, Air/Fuel Ratio/Mixture, and the Engine "Miss-Fires", at Idle Speed, because there "Is Not" enough Gasoline in that Idle "Mixture", to make the Engine "Fire Properly/Consistently", as in, "No...Miss-Fire"at Idle Speed), and, even though I couldn't "Detect Anything Wrong"...that there "Smog Sniffin' Machine", at, that there, "Smog/Emissions Testing Establishment"..."SURE COULD"...!!!...lol.........................................So then, if You would like some more help from me, I really need to know..."What Year and Manufacturer of Vehicle"...???..............."What Engine"...???................"What Carburetor"...and Model Number/Serial Number on it...as well as...."Does Your Vehicle have to be "Smog/Emissions Tested"...???............Thanks..............Till next time............Be Safe, take care, and have a good one.
RockysRoadshow hi rocky,, well your xplanation was pretty good, very well writen. the engine is a 3AU with a suspected swaped carb. AISIN 2 barrel simple/normal carb. 1.5cc and manual tranny. Its not gonna pass emission test right now, i probably do that in 2 years. cause the car is parked inside my garage (restoration project).i think the headgasket is making a bad misfire but ill fix that pretty soon. im waiting for my leakdown tester.. i just asked you about the throttle plate ,cause the repair manual doesnt have a base line for example " turn counter clockwise the speed screw until doesnt touch the shaft trigger or "where the accelerator cable is installed" . well , the manual doesnt say that as a start , just star with the typical toyota phrase.. screw all the way in the mix screws and then turn counterclockwise 1and a half turn as a start then blah blah.. I thought every carb needed the most vaccum but as far i understood you.. is to have the most vacuum with the proper rpm and also with a proper emission CO and HC values at THE SAME TIME, is that correct?
serchmarc Greetings serchmarc....I had a look-see, at some Information, on the good ole Internet, and, there happens to be, an, almost "Limit-Less" amount of Information, on just about Anything, and that Includes Your Vehicle as well...!!!...lol.....................................It appears, that, a carburetor, kinda like the One You have there, just might have, a number of Additional Gadgets/Smog Controls, in Addition to, a, let's say, a quite Primitive/Basic Carburetor, that was Manufactured, Before, all of the Smog/Emissions Testing started confronting All of Us.......................................What I would normally be doing, is, seeing if I could get, the "Exact", or, as close to the "Exact Information", as in, the "Information" that is usually found, in a..."Factory/Manufacturers Chassis Service Manual"...on, Your "Exact Vehicle", and, "If"...the "Carburetor", is Different From, the "Original, Factory Installed Carburetor", then, You'll be doing Yourself a big favor, by Finding the "Exact, Factory/Manufacturer's Information, on "It" as well....................................You can also, have a look, and see if You can find a "Website", that has a "Forum", that "Discusses", both Questions and Answers, about Your "Exact Vehicle", as, I'm pretty sure that, You will probably have, quite a few of them, to choose from, once You Find "Them" that is..good luck with that.............................................Now then, about You asking, about..."Vacuum...Proper RPM's....and the CO, and, HC Values"...???......In order to be able to "Pass" the "Smog/Emissions Test"...the Engine has to be in..."Good Shape/Not Too Much Carbon Build-Up, in the Combustion Chambers"...and,..."All Tune-Up and Maintenance Items"..."Should be Up To Date"...and, that also Includes the "Catalytic Converter/s...as well as..."All of the Adjustments"...that..."Apply"...to..."Any Adjustable Components"..."Must be Done Correctly, as per the Factory/Manufacturers Specifications"...or...the Chances of acquiring that Smog/Emissions Test..."Pass"...won't be very good at all..............................You see my Friend, when-ever I have to adjust a "Carburetor", like You see, in this UA-cam Video of mine, I do it, the following way, if it needs to be "Smog/Emissions Tested"...................Please Note, this Information "Only Applies", to this particular "Carburetor"...and..."Not Yours...!!!...lol................For Starters...the Carburetor, has to be in very Good working order, or, if not, I Re-Build it............................The Engine has to be fully warmed up to Operating Temperature, and the Choke is fully Off......................I Use a "Tachometer" (that's on my Automotive Specific Testing Meter), to Indicate the Engine's Crankshaft "RPM's" to perform, what is known as..."The Lean Drop Method" (that's right..."I Do-Not Use a Vacuum Gauge...!!!...but...You might have to, depending on what was Originally, on Your Vehicle's "V.E.C.I." Label/Sticker, if Your Vehicle had one, that is...???).....................................On that Same "V.E.C.I." Label/Sticker, it Also had Information printed on it, showing the Amount of CO, for a given, at Idle Speed, Air/Fuel Ratio, if an Automotive Garage, was using a Tail-Pipe Probe, and the Meter to Display, what the Tail-Pipe Probe, was sampling, in order to to do, the Required, Idle Mixture, and (Curb) Idle Speed, Carburetor Adjustments, to attain, the Label/Stickers "Specifications".........................I'm pretty sure, that the rest of, what I did, as it applies to, Adjusting/Setting-Up the Carter Thermoquad 4 Barrel Carburetor, that looks, really close looking, to the One that You see in this particular Video of mine, can be seen and heard, in this very Video.................Yes, indeed...the "Idle Mixture Screw Settings"...the (Curb) Idle Speed Screw Setting...as well as...the Engine's Crankshaft "RPM's", especially at (Curb) Idle Speed, have to, shall we say "Compliment One Another", and really should be "Adjusted", according to the "Factory/Manufacturers Specifications", in order, to, like I was sayin' earlier, to have..."A Better Chance at Passing the Smog/Emissions Test"...!!!................................If I were to just use a "Vacuum Gauge", it would only, take me as far as, getting to the "Stage", pretty much the Same, as when I Adjust the Idle Mixture Screws, to attain, the Fastest RPM's, Mixture-wise, at that 950 RPM's, that I Set the (Curb) Idle Speed Screw for, and, just "Before", I Started to perform, that.."Lean Drop" (Method) in RPM's, from 950 RPM's, Down to 850 RPM's, which, by the way, "Required" me, to use the "Tachometer", and "Not, a Vacuum Gauge", or, I wouldn't have a Clue, as to, where my HC and CO Levels were at.....................................Now for Excessive "NOX", or, Oxides of Nitrogen"...Tail-Pipe Emissions...............Usually at (Curb) Idle Speed, and at "WOT" (aka, Wide Open Throttle)..."NOX" Emissions, aren't much of a concern, but, at lighter engine loads, and at cruising speeds, oh, somewhere between Idle and WOT, let's say, then, probably due to, a somewhat "Leaner Air/Fuel Ratio", and the, Very Much Increased Ignition Timing (50 Degrees, give or take a bit), if it wasn't for, a Functioning EGR System, the "Increased", Peak Flame Combustion Temperature, would probably, make for some very High NOX Emissions, just sayin'......... .............Too much "Ignition Timing" (Advance Degrees at the Crankshaft), and/or, Too Much "Carbon Build-Up" in the Combustion Chambers, and, if, the Engine had an "EGR Valve/System", Installed On, or Near It, the EGR Valve, and its related Components, have to be, some-what Carbon-Free, and working Properly, or, any One, or Combination, of the just mentioned, shall we say "Items", are not behaving themselves (kinda like Malfunctioning, I guess), then, that "Smog Sniffin' Machine", would be Reporting, some, rather high "NOX Readings", on Your Test Report...!!!...(pssssst...equal, to the "Fail" word)...Yikes...!!!.............................So, I hope, what I was sayin' here, will be of some help to You.......................Yes-Sir-ee-Bob...all it takes, is, just "One Little Incorrect Adjustment"..or a, not working so good "Component/Part"...to make, just about Anyone's Vehicle, to be "Emitting Excessive Tail Pipe Exhaust Gas Emissions"...Over and Above..."The Maximum Allowable"...and, if that be the case...No "Pass" (word), will be seen, Printed on the Report that gets handed to You, at, that there "Smog/Emissions, Testing Establishment"...oh my...!!!.....................................Perhaps, have Your Carburetor "Fine Tuned" for Smog/Emissions Testing, by an Automotive Fix-Em-Up-and-Repair-Establishment, that is Qualified to do so, that has a "CO, and/or HC" Tail Pipe Probe/Meter Testing Unit, as by doing so, You won't have to worry so much, about, not getting it, as Critically Set, without the Equipment, that the "Shop" has............................I really hope, that You can find, the "Exact Specifications" for You Vehicle............Good Luck...........Till next time.............Be Safe, take care, and have a good one.
RockysRoadshow rocky thanks very long reply, ill read it later after work
DO U have video on setting the secondary/4- barrel?
+Gatewood's Computer Sales & Serv, Inc. ....Greetings Gatewood's Computer Sales & Serv, Inc. ....Thanks for watching.................. Sorry, but I don't have a Video (yet?), on how to, adjust/set-up, the Secondaries, on a 4-Barrel Carburetor at the moment..................If You can let me know, just which, 4-Barrel Carburetor, that You are talking about, then, I will (hopefully), be able to give You some Information, on how You might go about, making an adjustment or two, to the Secondary side of the Carburetor in question, and............till next time..........Be Safe, take care, and have a good one.
+RockysRoadshow 1975 Thermoquad like above, on Dodge 440 W200, used as snow plow
+Gatewood's Computer Sales & Serv, Inc. ....Greetings Gatewood's Computer Sales & Serv, Inc. ....Well, I do have, oh, about 24 Carter Thermoquad 4-Barrel Carburetor UA-cam Videos, one of which, Shows/Talks, about, how the Thermoquad's Secondary Air Door Works, along with, a few of the Adjustments, to be looking out for, and "Only Some" of those Adjustments/Settings, on the Secondary Air Door/Valve, can be made "Without Affecting", some of the "Other Adjustments", that have to be made, in the "Correct Sequence/Order of Doing Things", or, the Thermoquad Carburetor, will more than likely..."Not Work So Good"...!!!.................The "2-Things", that can be Adjusted, on the Secondary Air Door/Valve (with-out messing-up the Other Settings/Adjustments), are...the Secondary Air Valve/Door''s..."Spring Wind-Up" (Tension)...and the "Fully Opening Amount", of the Secondary Air Door/Valve, against the Metal-Tab-Stop (as You will see, in my UA-cam Video)..............A Thermoquad Carburetor "Rebuild Kit" or Factory Chassis Service Manual, will usually have, all of the Required Adjustments/Settings, that "Have to be Done in the Correct Sequence"...!!!.............If the Choke Pull-Off, is quite Old, it could Leak Air/Vacuum, Stick, or maybe Not Relax fast enough, which, as I've experienced in the past, makes for a TQ that Runs/Performs like (use Your Own, not so pleasant word here...lol).................Then, there's also, a little teeter-totter like Catch-Lever, that has to grab-onto, the secondary throttle shaft's bracket, but only when the Choke, and its Linkage is Fully Off.............Over the years, when a Thermoquad Carburetor gets Older, and/or, has the Mileage/Kilometer-age piling up on it, then, Parts, like the Floats, Needles & Seats, Choke Pull-off, Accelerator Pump Seal/Cup and Check Valve, etc., start getting old too, and probably, shall we say, worn-out, some-what as well, which, will at times, make-for a Thermoquad, that doesn't Perform, as good as it's able to, and Gas Mileage, might suffer as well, possibly....................You can find that Thermoquad, Secondary Air Door/Valve Video, on my UA-cam Channel...RockysRoadshow...and, I think the Title of it is...Thermoquad 4-Barrel Carburetor (Part 7)...if not, just look for the Thermoquad Video that has...(Part 7)...on the end of the Title...oh, and, if You care to, You can have a look at, the Other 23 Thermoquad Videos as well...enjoy....................If You need any more help at all, feel free to post a comment or question, under any of my UA-cam Videos, and........till next time..........Be Safe, take care, and have a good one.
Hello. Can you tell me how do adjust a idle speed screw? How to set the "zero" position?
Greetings grucu....Thanks for Watching, and for Your comment and question as well....In order for me, to be able to even point You in the right direction, as to You maybe, being able to make the required adjustment/s, as it pertains to, what it is, that You happen to want to make adjustment/s to, then, You are going to have to tell me, first, just...What, Car or Truck???...What Year???...What Engine???...Any Modifications or Upgrades at all???....Before I can even consider helping You out with any adjustments what-so-ever, then, just like a "Medical Doctor", I have to know as much as I can, about the "Patient", before I will be able to "Diagnose", and maybe "Prescribe" some "Information", that, I hope, will be able to help You out, in, getting Your Vehicle Running "Great" once again...!!!
So then, if You can tell me, as much as You are able to, about the Vehicle, that You want to perform some adjustments on, then, hopefully, I just might be able to...Help You Out...
Be Safe, take care, and have a good one.
RockysRoadshow thank You for your answer. My car it's a Chevy Blazer K5 with non original GM 327cui with automatic th350 and Rochester 4MV with divorced choke :)
grucu
Greetings grucu....Yes, indeed, it helps quite a bit, when I have some specific information to go on....You are in Luck, well, depending on, just which "Model Year"..."Rochester-Quadrajet-4MV" (4 Barrel Carburetor with Vacuum Secondaries, and, just like You said, the "Bi-Metallic-Coiled-Up-Choke-Spring"..."is"...Divorced, as in "Separated From" the Carburetor, and is installed in the Intake Manifold, and, the actual Actuation of the Choke Mechanism is done via a linkage rod).
You had mentioned in Your First Comment, about..."How to Adjust an Idle Speed Screw"...and.."How To Set"...the..."Zero Position"...???
I'm hoping that You are talking about, what is commonly know, as the "Curb Idle Speed" perhaps...
The Rochester "4MV" Quadrajet Carb, that I'm very familiar with, is one that "Does Not" have Any "Additional Gadgets" on it, with the exception of a PCV (Positive Crankcase Ventilation) "Port" (as in metal pipe, to connect that slightly larger PCV Hose to), and a "Port" for the "Vacuum Advance" Hose, that connects to the Vacuum "Canister", that's mounted on the "Distributor", and also, a "Port", that connects that quite short Vacuum hose to the (Dual Function) "Choke Pull-Off/Secondary Air Door Regulator".
There are a few things that come to mind (mine, that is)...
Does Your Rochester "4MV" Quadrajet Carb, have an "Idle Speed Solenoid", or something that Looks, kinda the same, and if I recall correctly, it was probably called a "CEC" (as in...Combination Emission Control) Valve (I think?), and, this so called "CEC" Valve, will usually look much like an Idle Speed Solenoid, with the "Difference" being, that the "CEC" Valve...will "Also" have a "Vacuum Hose" connecting to it.
"Warning...Caution", if Your Rochester "4MV Quadrajet" Carburetor happens to have that "CEC" Valve that I just mentioned above, You will have to "Understand" It, before making any Adjustments to it, because, if it is "Not Adjusted Properly", the Engine might "Stall" and "Stop Running", and, if Your Vehicle happens to have "Vacuum Assisted Power Brakes"...then..."No More" (Vacuum) will be available for the "Power Brake Booster"...!!!
The Rochester "4MV" Quadrajet, that I know quite well, was like I was sayin' earlier..."Did Not" have an Idle Speed Solenoid...or...a "CEC" Valve on it what-so-ever.
You said that You were wanting to "Adjust" the "Idle Speed"...is that "Correct"...???
Make sure that Your "Choke" is Fully "Off" when Your Engine has Fully warmed-up to "Operating Temperature", or, if the Choke's "Fast Idle Cam" is still in "Contact" with the (choke's) Fast Idle "Screw", that in itself, can cause..."Too Fast of an Idle Speed".
Please, let me know, if Your "4MV" Rochester Quadrajet has an Idle Speed "Solenoid" or a "CEC" Valve on it, that way, I will be able to properly address, Your...Idle Speed "Situation".
Also, is Your Engine..."Idling Too Slow"...or, is it..."Idling Too Fast"...and...weather the Engine is..."Cold"..."Warming Up"...or "Hot"...???
'till next time...
Be Safe, take care, and have a good one.
What can i get to be able to do this ? Gage or meter of some kind. Thx
Greetings blakesupra....In order to Observe the RPM's (Revolutions Per Minute) of your Engine, all that's required is, what is called a Tachometer (or, Tach, for short)....Try to get one that looks something like the "Yellow-Multi-Meter" that you see as my UA-cam Channels Thumbnail Picture, and in some of My Channels (RockysRoadshow) Videos as well....My Yellow-Multi-Meter is very good for doing all kinds of Tests, when it comes to a Vehicle, and then some....This Yellow-Multi-Meter is far more Accurate then that Big Analogue Meter that you see in this Video (Analogue Meter has that Waving Needle/Pointer).
My "Digital" (shows Big 1-Inch High Numbers on the Display/Readout) Yellow-Multi-Meter can measure all kinds of things....DC Volts, Ohms (or resistance), DC-Amps, Duty Cycle, Dwell & Tachometer with engines that have a different number of Cylinders, an Audible (tone) that indicates a good electrical circuit with low resistance, and, if that's not enough, I could, as an Option, Buy a Temperature Probe that plugs into this Muti-Meter to measure Temperature!
I bought this Muti-Meter within the last 10 Years, and it has more then paid for itself, I must say!
I paid about $85.00 Canadian Dollars for it, if I recall correctly....A very worthwhile Investment, if I do say so myself.
So, if you can get a Muti-Meter that is able to do, most of what mine can, then that's about all that's needed for the "Average-Joe" working at home, on His or Her Own Ride (Vehicle).
Oh No, are you getting that same "Car-Bug" that I got quite a while ago?...You know, Car-Bug, as in working on Cars, Trucks, or whatever, as a Hobby?....Welcome to the Club!...lol.
Take care, and have a good one.
My emission testing report before I sent you my info on my 77 Ford T-Bird 350M. This is my fail test report any help you can send me would be greatly appreciated. (HC)-- Loaded Reading 46, Loaded Standard 250 Loaded Result--PASS. (HC)--IDLE READING 729, IDLE STANDARD 250, IDLE RESULT--FAIL. My (CO) IN %--LOADED READING 0.23, LOADED STANDARD 1.50, LOADED RESULT--PASS. (C0) IN %--IDLE READING 6.88, IDLE STANDARD 2.00, FAIL. So, that's where I'm at with my emissions result. Will be readjusting my carburetor and start fresh with it. Hopefully I'll be using your method and make it work, thanks.
Greetings...Rogelio Camarena..........Well, as far as the "loaded" part of the smog test is concerned...(probably means, while the Dyno Rollers are being turned/spun, by the vehicle's tires, and are probably simulating, about 25 Miles per Hour/40 Kilometers per hour, as a guess), then, the "loaded" readings, sure look, to be pretty good, to me, alright..........The, shall we say "Un-Loaded" idle/speed test, is where it appears, that the "not-passing-the-smog-test" shows up..........The carburetor's..."Idle Mixture Screws"...as well as, the..."Curb Idle Speed Screw" (or maybe Solenoid, curb idle speed setting, if so equipped), have to be "Set Correctly", or, more exhaust emissions, over the maximum allowable, will usually be the result..........Also..."ignition timing"...has to be set to "specifications" as well, b-cuz, if it's "not set" properly, then, that can also, have quite the affect, on what the smog-sniffin' machine, might be detecting, as far as, excessive exhaust gas emissions are concerned...........Also, all of the ignition system parts, have to be in very good condition/almost like new, b-cuz, all it takes, is, just one misfiring spark plug, that will be sending excessive/extra/not wanted or needed, exhaust gas emissions, right out the end of the tail-pipe..........Also, if there is a fuel system problem, and/or, a wrong air/fuel ratio (mixture), then, that, in itself, can be the cause of, one or more, "misfiring" (engine) cylinders..........Also, things like the air filter, and the PCV/Positive Crankcase Ventilation, Valve and system, have to be good-n-clean, and not plugged up.............On my very first time, having to go through the smog test, I thought that I should lean-out, the 2 idle mixture screws on the carb, so, I turned the 2 of them, in, as far as I could go, and still have a nice smooth idle..."Wrong"...(that was), b-cuz, I got around, about the same as you got, around..."700-plus"...HC/Hydrocarbon reading...!!!...(maximum allowable, was 500 for me, as I recall), and, that's when I learned, that, by turning the idle mixture screws..."in too much/too far in"...that it caused, what is called, a..."lean misfire"...!!!...(that's usually when, and in this case, was when the air/fuel mixture, became too "lean", at idle speed, and caused that lean-misfire), and I sure couldn't tell, that was so, b-cuz, the engine was idling really smooth at the time............Have a look around, in your T-Bird's "engine compartment/engine bay", for a "V.E.C.I." (Vehicle Emission Control Information)...Label or Sticker...b-cuz, there's usually some good information, that's printed on it, and, if Ya get lucky, it will be showing, the specifications/settings, that could very well be...Smog...related as well..........I'm thinkin', that your 1977 T-Bird, will probably have a (Ford) 2150...2-Barrel Carburetor, sitting on top of, the probably, Windsor (spelling?) 351 Cubic Inch V-8 engine (I've never heard of a Ford "350" before, and, I use to have a 351 Cleveland, a long time ago, as well)............I've spent quite a bit of time, working/messing with the (1972 & 1973) 2100 model carb, and, there's probably not much of a difference, but, visually, there is probably a separately mounted "choke pull-off", on the 2150 model, where-as, the choke pull-off, was actually part of, the 2100 model carb itself, as I recall...........Have a look, for that..."V.E.C.I."...Label/Sticker...and let me know, whether or not, you find one, and we can go from there, if need be............Good luck, and.......till next time.......Be Safe, take care, and have a good one.
What Tach do you recommend these days?
Greetings...Roger Stevens.........Thanks for watching.........Each type of Tach/Tachometer, has its own strengths and weaknesses.........If it's accuracy Ya want, then, a digital Tach is probably the way to go, and, an example of one, is shown in several of my UA-cam videos, on this channel...RockysRoadshow...(it's the yellow multi-meter, that's made specifically for automotive use...it has, tach, dwell, duty cycle, dc volts, ohms, dc amps, diode testing, and, it even has, a temperature testing setting on it, that I can use, if I were to purchase the optional probe for it)...so, have a look see, at some of my videos, where it is shown, being in use...enjoy.........The analogue meter (that's the kind, that has a needle, that waves at you...lol), is good for watching the changing, shall we say, trend, of, oh, let's say a fairly low voltage, as it fluctuates up and down a little bit.........A good visual representation, would be, an analogue Tach, that shows the engine RPM's as the engine moves though the different rotational speeds, of the engine's crankshaft.........In time, you might end up having, at least, one of each type, just like me...lol...and.......till next time......Be Safe, take care, and have a good one.
I typed in adjustment for 2 4 barrels for a 61 corvette. This didn't do a thing for me. I already know about adjustment on 1 carb
Greetings...jack orr……….Well, a pretty simple way, to get those two quads (2, four barrel) carburetors, idle mixture screws, adjusted reasonably well, would be, to use a "vacuum gauge", to obtain, the "highest" vacuum reading, when the engine is fully warmed up to operating temperature, and is also, at the desired idle speed (make sure, that, the choke is fully off)………...Here's what I would do...…...Engine "not running", then, turn all of the idle mixture screws, in very lightly, until they stop, then, put a chalk mark (or whatever mark), at the 12 o-clock position (as in, pointing at the sky), on each idle mixture screw, for a reference point only...……..Then, turn them all out, oh, about 3 turns out, should be ok, to get, the already warmed up to "operating temperature" engine running (idling)………..Vacuum gauge was already connected to the intake manifold (to measure manifold vacuum), then, you have to decide, what the "target" idle speed will be (try to keep it under 1,000 RPM's, or, the carb/s, might transition into the primary fuel circuit)…(sometimes, the initial timing has to be altered, to get things right, and also, make sure, that, your "total" timing is correct, and not "over-advanced, or, damaged engine, it just might be...!!!)...(total timing is, initial/base, plus, the amount of mechanical ignition timing advance, that, the centrifugal advance weights will provide, when they are "fully" slung outwards).........A lot depends on, just how "aggressive", that your camshaft really is..........Factory/stock cams, are usually easy, to get the idle mixture screws, adjusted well...........As for really, shall we say, "lumpy" cams, then, the "ignition advance curve", as well as, usually, a quite high (in advance degrees), of initial/base ignition timing, that, those lumpy cammed engine's need, to sustain, a reasonable idle..........By trying, to get the lumpy cammed engine, to stay idling, by just turning in, the idle "speed" screw/s (too much), then, a really smoky exhaust, it will usually be..........So, just adjust those (probably 4), idle "mixture" screws, reasonably, the same amount of turns and partial turns out, and try to get the "highest" vacuum reading (measured in Hg, or, Inches of Mercury), on the vacuum gauge, when "both" idle "speed" screws, are set, to your chosen "target" idle speed............It's kinda like a juggling act somewhat, as in, when you turn, one or more idle "mixture" screws, then, the idle "speed" usually changes (higher or lower)..........Just adjust the idle "speed" screw/s, to keep the idle speed, at your "target" (warmed up engine) idle speed, that you want, to end up with........Well, there is some basic stuff for Ya, that I hope will be of some help to you..........Good luck, and.......till next time.......Be Safe, take care, and have a good one.
I have a 4350 carb on a 1976 ford 460 like 59 caddy the rpms drop when i tighten the screws from the get go should I back them off even more then the 4 turns or are the needles shot any help would be greatly appreciated. I failed smog at idle not hat 2500 rpms. Thanks
Rick Bensco Greetings Rick Bensco....Thanks for watching this UA-cam Video of mine.................................................Yes, indeed, getting everything set-up right, can be quite the challenge, at times, when it comes to getting Your Vehicle's Engine to run and behave, in such a manner that will satisfy, that good ole "Smog Sniffin' Machine's" ability to "Sense and Report" any Tail pipe Emissions, that are over and above the required Level of, shall we say, Acceptance, in order to have that nice word, being..."Pass"...printed on the Report, that You receive, after that, good ole "Smog Sniffer" has had its chance to Sample, what ever it is, that's coming out of Your Vehicle's tail pipe..........................................................."If"...???...it all boils down to, just having Your Vehicle's Carburetor, set-up, and adjusted, for Your Engine's..."Curb Idle Speed, and Idle Mixture"...then, as I see it, there are a few options that are available to You................................................First thing to do, is to have a look around in Your Vehicle's Engine Compartment, for what is known as a..."V.E.C.I." (aka, Vehicle Emissions Control Information)...Label or Sticker (usually it's a White Sticker/Label, with some Important "Information" on "It"), that will usually, be very Helpful, in getting Your Vehicle's Engine's Components, set-up & adjusted properly, so Your Engine, will, for the most part, be operating, shall we say..."Clean Enough"...as in, "Limiting" the Amount of "Excessive Exhaust Emissions", that will be Under the..."Maximum Allowable"...that will enable Your Vehicle, to receive that good ole..."Pass"...Stamp of Approval....................................................On at least "2" occasions, I found that, by doing the..."Lean Drop Method"...like I explained, how to do, in this particular UA-cam Video of mine, on "2" Different Carburetors, by a "Lean Drop Amount of 100 RPM's" (RPM's = Revolutions Per Minute, of the Engine's Crankshaft), that by doing so, gave me that good ole..."Pass"...stamp of approval, on my..."Smog Testing Report"...and, by receiving that "Pass", I'd say that, the "100 RPM Lean Drop", that I performed, on "Both" Carburetors, worked rather well................................................If You are not able to find any "Specifications", as in, on a V.E.C.I. Label/Sticker or other-wise, I would probably do the following......................................................Vehicle "Exhaust" is "DEADLY"..."Make Sure" that, there is Plenty of Ventilation and Fresh Air Around Your Vehicle, when-ever Your "Vehicle's Engine Is Running"...!!!.........................................All "Lean Drop"...and..."Curb Idle Speed"...Adjustments, are done with the Vehicle's Transmission, In "PARK", on Level Ground, with the Tires Chalked, and the Emergency/Parking Brake On as well..............Have the Engine Fully Warmed-Up to Operating Temperature..............then, "STOP" the Engine............then, make sure that the Carburetor's Choke is Fully Off...............then, Turn-In Both "Idle MIXTURE Screws" In, until Both of them, are "Lightly Seated", and then put a white chalk mark, on the Idle MIXTURE Screw's Heads, at the 12-oh-clock/up position, then, back them "Out"..."4-Turns" each...............then, I would Connect my "Tach" (as in Tachometer, to see the RPM's of the Engine's Crankshaft)................then, Re-Start the Engine...........then, "Set"...the "Idle SPEED Screw or Idle SPEED Solenoid" (as the case may be) to achieve "700 RPM's in PARK" (automatic transmission)...............then, Adjust the Idle MIXTURE Screws, "One" at a time, Inwards, and later, probably Outwards as well, until the "Highest RPM's" were showing on the "Tach", and, You will have to probably, have to do it several times, in order to get it "Fine Tuned"...............You will probably Notice, that the "RPM's on the Tach", will usually "Increase" as the "Idle Mixture Screws" are Turned "In".................just simply..."Re-Adjust"...the "Curb Idle SPEED Screw or Solenoid"...Back to that "700 RPM's"...After making an Adjustment to the either of the..."Idle MIXTURE Screws".................Once You have established the..."Fastest RPM's"...with, Both of the..."Idle MIXTURE Screws"...while having, the..."Idle SPEED Screw or Solenoid"..."Set At that 700 RPM's"...then, it's just a matter of..."Turning In" (for a Leaner Mixture) the..."Idle MIXTURE Screws"..."Exactly the Same Amount of Turns/Partial Turns"...(please note, Carefully rub off the Old chalk marks, and put on New Chalk Marks, at the 12-Oh-Clock/High position, on those "2" Idle MIXTURE Screws..."BEFORE" Doing the "Lean Drop" in RPM's)...........Just "Remember" to..."Not Adjust the Curb Idle SPEED Screw or Solenoid"...when Doing the..."Lean Drop" (in RPM's) with the..."2" Idle MIXTURE Screws"...or...it just..."Won't Work"...!!!................Also, once You have Completed the "Lean Drop"...Adjustments...then You will have to "Make Sure", that Your Engine's..."Curb Idle Speed"...is "Correct", in RPM's, as shown on the "Tach", when Your Vehicle's Automatic Transmission is placed in "Drive", and, with the "Brake On"...while You are In the Driver's Seat...to the..."Factory/Manufacturers"..."Specification" (should be on the V.E.C.I. label/sticker, if You have one, that is)...................................................If the "Curb Idle Speed", while the Auto-Trans is in "Drive", and with the "Brake On", and You in the driver's seat, needs to be Adjusted, then, just use the..."Idle SPEED Screw or Solenoid"..."ONLY"...to..."Set" the Engine's..."Curb Idle SPEED"...and, for "Safety's Sake", make Your Final "Curb Idle SPEED Adjustment, with the Automatic Transmissions Selector in "PARK"...then place the Auto-Tans in "Drive", while You are in the Drivers seat, with the "BRAKE ON", and see what the "Curb Idle Speed" is, on the "Tach" (please note, the "Tach" has to be seen, while You are in the Drivers Seat, when Checking the Final, Curb Idle SPEED)...and..."Do Not Re-Adjust the "Idle MIXTURE Screws"...or....You'll..."Mess-Up"...the...Carburetor's..."Idle Mixture Settings"...that You originally, and painstakingly, went to all the trouble to go through, just a short time ago...!!!................................................There's "No Guarantee", that My "Lean Drop Settings", will enable You to "Pass" the Smog Emissions test, but it should be very close, just sayin'...........................................You'll have to find out, the.."Specified"..."Curb Idle SPEED"...while in "Drive"...for Your "Exact"..."Vehicle...Engine...and Transmission"...while Your Vehicle's Engine is..."Idling in Drive"...with You In the Driver's seat, as, that is..."Super Important"...in helping Your Vehicle, to have a much better chance at "Passing the Smog/Emissions Test"...!!!................................................Another "Option" is................You can phone around, and see if there happens to be, an Automotive "Fix-Em-Up-Establishment", that has a..."HC/CO" (HC = Hydrocarbons & CO = Carbon Monoxide) Testing Unit, where, the Unit's Tail Pipe Probe, takes a Sample of Your Engine's Exhaust, from Your Vehicle's Tail Pipe, and, then, the "Technician or Mechanic", will be able to "Adjust" Your Carburetor's..."Idle Mixture, and Curb Idle Speed"...to the required Settings, that will give Your Vehicle, a much better chance at acquiring, that much needed "Pass" that You need....................................................Even "If" Your Carburetor was "100%" Capable, of "Passing" the Smog/Emissions Test, that my Friend, is Only "One" part of what is Needed to keep "Exhaust Emissions" with-in Allowable Limits.........................................Here are a few things to consider, which also depends, on the "Type" of Smog/Emissions Test being conducted, for any given Vehicle...................................The Engine itself, has to be in very good Mechanical Condition, along with, not too much Carbon build-up in the combustion chambers/head/s, and even the Motor Oil has to be fresh and clean as well...................................Air and Fuel Filter/s must be Clean......................Now on to the "Distributor"............The Initial/Base Ignition "Timing", plays a "Big Role", in a Vehicle's Engine, that has to be "Smog Tested"................................................Things like, too much Initial/Base Ignition Timing...too much, or too quick, of a Centrifugal/Mechanical Timing Advance...and also, too much, or, too quick of a Vacuum Unit's Timing Advance, will usually "Increase" the Amount of "Exhaust Emissions" as well...!!!...................................................Bottom line here is..................Keep all Parts and Pieces "Factory Stock"...and Use the Vehicle's "Factory/Manufacturer"..."Tune-Up Specifications and Adjustments", for a Vehicle, that has to be "Smog/Emissions Tested"...especially, if it is something, like the "California" (and maybe New York as well?)..."Smog/Emissions Test"...as, not only will the "Sniffer"...be..."Sniffin'...but, I've heard that, they be "Checkin' under the Hood"...and..."Under the Vehicle"...for the "Special Certified Smog Parts", for the Vehicle in question as well...!!!...Yikes...!!!...lol...............................................So then, see if You can find, any and all "Specifications" for Your Vehicle, as that will really help a lot...!!!.......................................I still don't know if You have a Car or a Truck...???................................If You have any further questions or concerns, just let me know, in a comment or two, under any of my UA-cam Videos.........................Good Luck, and, until next time.................Be Safe, take care, and have a good one.
RockysRoadshow Thanks! I have an old RV I drove it 2 years ago from CA to NY and Back. The truck runs pretty good a little bogged down on the hills but not too bad. I just got back from the smog test and my H/c was still not good my co was fine but not h/c at idle bummer I'll try this again from start to finish. Thanks again
Rick Bensco Greetings Rick Bensco....Here are a few more..."Clues"...for Ya, as to what just might be causing Your Engine's, Higher then Wanted, at Idle Speed..."HC" (Hydrocarbon), tail pipe Emissions..................................................If there happens to be any..."Vacuum Leaks"...due to things like..."Miss-Routed, or Disconnected, or Cracked/Split Vacuum Hoses"...or maybe, a...Not 100% Closing...EGR (Exhaust Gas Recirculation) Valve, due to something like, Excessive Carbon Build-Up, which will usually Prevent "It" from Closing all the way, and also, Any "Gaskets" that might be Leaking, that could very well be, causing a Vacuum Leak, as well ................................................If Your Vehicle is equipped with a "Catalytic Converter", It also, has to be Functioning Properly as well.................................................If Your Engine is Equipped with an Air Pump (aka, Smog Pump...lol)...then, "It" has to be working properly, as well my Friend, as "It" kinda works, some-what like an "After-Burner", in the Exhaust Manifold/s, where-by, the "Unburned HC's", that Exit the Engine's, Head/s, Exhaust Ports, gets "Mixed" with that "Fresh Air", that the Air/Smog Pump...Pumps into the Exhaust Manifold/s, which in turn, as I see it, makes for what, I do like to call, an "After-Burner", b-caws, that there "Fresh Air", that is Added to the very Hot "HC's", will enable those very Hot "HC's" to "Continue Burning" in the Hot "Exhaust Manifold/s", b-caws of the Oxygen, that's in the "Pumped-In" Air, makes for a "More Complete Burning", of the "Un-Burned Portion" of the "HC's", while "They" are "In" the Hot Exhaust Manifold/s...................................................The Engine, has to, have had, a Proper "Tune-Up", not all that long ago, and that Engine, has to have, New, or As-New, Ignition and Fuel System Parts & Pieces, along with Clean Air and Fuel Filters, and also, has to be "Correctly Adjusted"...to..."Factory/Manufacturer's Specifications" as well................................................Sometimes, as I've experienced in the past, there was some "Crud/Debris/Yuck-ees", that got Stuck, in my Carburetor's "Idle Circuit"...in around the "Mixture Screw Area"...there-abouts, which had my Car, almost "Stalling" at a Red Light................................................So, I managed to Nurse the Car back home, and, I made a Note, of the "2" Idle Mixture Screw's..."Turns and Partial Turns"...from being "Lightly Seated" and Fully Closed", so that I'd be able to "Set" Them "Back where They were Originally"...................................................Once I "Removed" Both Idle Mixture Screws", I got a hold of a length of Neoprene, Fish Aquarium, Air Pump..."Clear Tubing" (about 1/8 Inch, Inside Diameter, I think), and, like Blowing-Up a Stubborn Party Balloon, I used Lung Pressure, via my mouth, to make like a Mini-Compressor, and I Blew really hard, through the Clear neoprene Tubing, while it was pressed against, each of the Carburetor's..."Idle Mixture Screw"..."Holes"...hoping to..."Dislodge/Remove"..."What-ever-It-Was"...that, what I thought, just might be causing, that..."Not-Working-so good"..."Idle Circuit"..in my Carburetor...........................................Once I "Re-Installed" the "2" Idle Mixture Screws...and..."Back to Their Original Positions"...(and hearing a Drum Roll)...I Started the Engine, and..."Guess What"..........................."ALL FIXED"...and the Engine was Idling..."Just Great"...!!!...(I Bow, and say...Thank-You, Thank-You very Much)...lol.........................................If the Carburetor on Your Engine, has gone quite a Few..."Miles/Kilometers, or Years"...since it has had a..."Complete and Properly Adjusted Rebuild"...as well as making Any...Modifications, as in, something like, Re-Calibrating the Fuel Jets, on a much Older Carburetor, that was probably "Calibrated" for 100% Real Gasoline (that be Gasoline, that Does-Not have any Ethanol/Alcohol in it...!!!), way back when, as opposed to, trying to having that Much Older Carburetor, trying to Supply the Engine, with the Required Air/Fuel Ratio at All Engine, Speeds and Loads, while that poor Old Carburetor is being "Fed" (as in Feed or Feeding) the current day Gasoline, that usually has "Ethanol" (Alcohol) in Its "Blend", which by the way, will some-what make, a Much Older Carburetor, that was Calibrated for the Good Ole 100% Gasoline (that was available, many Years ago), and as I've experienced personally, a Carburetor, while being Fed, Gasoline, with about 10% Ethanol in it, would cause, that particular Engine to..."Lean Surge", while Traveling at City Speeds (Lean Surge, is when the Engine actually Surges, or kinda makes the Vehicle, Jerk, or Buck, back and forth, and I'm sure, that Everybody, while in that particular situation, would actually Feel, that Somethin's Up...!!!) .........................So then, if You care to, and with Your Engine "Cold and Not Running", You can "Visually" Check-For, things like...Missing, Disconnected or Damaged...Vacuum Hoses and Electrical Wiring, and/or, just about Anything that looks like "It's" out of place, or just Doesn't Look Right, just sayin'.................................................Before I forget, just about "Any Vehicle", that actually "Does Pass the Smog Test", will for the most part, be getting "Better" Gas Mileage/Kilometer-age (aka, Fuel Economy), but only If, a Person goes..."Easy on the Gas Pedal"...and, if that Person does, that "Gas-Pump-Bandit"..."Won't be Taking as Much of Your Hard Earned Money"...at as..."Fast-ah-Rate"...as a Vehicle that...."Failed the Smog Test"...and usually gets called, a..."Gas Guzzler" (maybe?...lol)......................................From my experience/perspective, it sure "Doesn't Take Much", along the lines of, shall we say, Something that Isn't Working Properly, Connected Properly, or Adjusted Properly as well, that will cause, just about any Gasoline Engine out there, to be...Spitting/Spewing, Excessive Exhaust Emissions, out of the Vehicle's Tail-Pipe/s, and, that's, pretty much a given (Fact), and, as You've already experienced, that Fact, happens to be...that You...just..."Can't Fool that Smog Sniffer, at the Smog Sniffin', Testing Establishment"..."What-So-Ever"...!!! (aka, "It's kinda like, a "Mechanical"...but Can't Run..."Police Tracking Dog"...!!!)...and lol, but only if it isn't You, that gets handed that "Smog Report"..."With-Out"...the..."PASS"...Word...Stamped On..."It"...!!!............................Ah yes, time for that, good ole saying, and, as I see it, could be applied, to an Engine, that "Won't Pass the Smog Test" (due to somethin'...that just Aint Right)...and that Saying happens to be..."The Chain is Only as Strong as the Weakest Link"...!!!...(or Snap!)...................Good Luck...and........Till next time................Be Safe, take care, and have a good one.
RockysRoadshow Thanks again I'm going to give it another try today. Thanks
I need to adjust the cold choKe on my quaradrajet--1985 boat motor. The port side motor idles too high until the motor warms up- about 2000 RPM, would be much happier if I could get it down to 1200 RPM--this carb doesn't have the set screw under the vacuum device
Greetings patswil1....Thanks for watching this UA-cam video of mine, and, for Your comment/question as well....I haven't had any "Hands On Experience" with a "Marine Specific" Rochester Carburetor to date, but, I'll mention a few things, that I hope, will help You out somewhat....You had mentioned, that You didn't happen to see, what is normally referred to, as a "Fast Idle Adjustment Screw", and the Fast Idle "Cam", that goes hand in hand with it, Under, what is usually, a Choke Pull-off Diaphragm, that also Functions, as a Secondary Air Door Control/Modulator (aka, Air Valve Dashpot).
I had a look see, at some pictures of Rochester Quadrajet "Marine" Carburetors, and indeed, some of the "Choke Control Mechanisms", are "Quite Different", from, what I'm use to seeing, in comparison to, "Land Based" Rochester Carburetor equipped, Cars and Trucks, that are Usually Equipped with that, good ole..."Fast Idle Cam & Adjustment Screw!"
If I was in Your situation, I would be looking for a Factory or After-Market "Service Manual" for Your "Exact" Boat/Engine/Carburetor/etc.
Also, I would be Visiting some of the Many..."Boat/Boating" Related Web Site "Forums", where, most of the time, there just might be, a Person or Two, that has already "Encountered" the same "Faster-then-wanted", Cold Engine, Fast Idle Speed, with the, hopefully "Correct Procedure", that will Reduce those (cold engine) "Excessive" Engine RPM's to an Acceptable Level, that, will be, in the RPM Range, that will be, acceptable to You.
In most cases, all I have to usually do, is, take a look at something, such as, the "Choke Mechanism" on Your Port (aka, Left Side) Engine, and, it sure wouldn't take me very long at all, to figure out, how it operates, and, how to Adjust it as well...but...unfortunately, I'm not there, and, Your Boat isn't here!
With "Both" of Your Boats Engines "NOT RUNNING", move the Required Levers and/or Carburetor Linkages (I'm not sure, but, You might need someone else, to operate the Throttles or Choke actuating Controls, if those Controls are located at the Boats "Helm").
Have a look at how Your "Starboard" (aka, Right Side) Engine's Choke Linkage/Mechanism Operates, as it's moving, as well as, the Distance, that the Linkage or whatever Actuates the "Choke Related Gizmos" Travel, and, maybe take some measurements as well.
Like they (keep) sayin'..."A Picture is Worth a Thousand Words!"...
...&...
...in this (well, actually Your) case, those so called Pictures, are Actually, what You'll be Seein', if, and when, You happen to Observe, the "Movement" of, those "2", dare I say Identical Engine Control Systems (maybe, with the exception, of, having Controls, being "Specific" for, that of, one for the "Port", or Left Side Engine, and the other set of Controls, for the "Starboard", or, Right Side Engine).
Please, be sure, to Run Your Bilge/Engine Compartment "Ventilation System", for the Recommended amount of time, to "Evacuate", any Gasoline "Fumes", that may have accumulated in Your Boat's Bilge/Engine Compartment, "Before" Starting those "2" Engines!!!
Best of "Luck", with lowering Your Boat's, Port Engine's, (cold engine), fast idle speed, to an acceptable rpm level.
Steady as She goes "Captain", as You Ply those Waters, with Your Vessel's Plotted Course...
...Be Safe, take care, and have a good one.
So how is this set up so ypu can do this off the car?
Greetings...Devlicious............Thanks for watching...........Well, in order to, shall we say..."fine tune"...the idle mixture screws, along with the (curb) idle speed (RPM's), as in, just having the engine at idle speed (idle speed screw, or solenoid adjustment), then, it's pretty much a given, that, the engine has to be running, and, is also up to operating temperature, with the choke fully off...........Here are some adjustments, that, can sometimes be made, while having the carburetor, off of the engine...........These adjustments, are usually called..."bench adjustments"...(as in, on the work-Bench)...........Most carburetor "rebuild kits", will usually have these, so called, "bench" adjustments, explained on the instructions (sheet/s of paper), that come in the kit, that usually have, both, printed words, along with some pretty good pictures/drawings as well............Things like, basic (base) settings for...idle mixture screws...curb idle speed screw or solenoid ...choke linkage and fast idle speed screw...choke door (flap)...and if applicable...secondary throttle plates, and/or, secondary air valve adjustments...etc..........Me, myself, if I don't happen to have any instructions, for carburetors, like, oh, let's say, a...Rochester 2 or 4 barrel carb...a Carter Thermoquad...or maybe, a...Motorcraft/Autolite 2-barrel carb...then, I usually just open the idle mixture screws, about 3 Turns out, from being "lightly" seated, so as not to, cause any damage at all, and, this basic/bench setting, is just to get the engine started and warmed up to operating temperature, so I can do the final, fine tuning, of the idle mixture screws..........If, having to go through the "smog/emissions" test, then, pretty much all adjustments, have to be done, shall we say, "super correctly", or, if not, then, that..."smog sniffin' machine"...will absolutely, be able, to "sniff", that extra, not wanted air pollution, that's exiting the vehicle's tail-pipe...!!!...lol...........Be very careful, so as, not to come in contact, with any, hot or moving engine parts and pieces...!!!...........So, there you have it, well, for now that is, and........till next time........Be Safe, take care, and have a good one.
RockysRoadshow cool thanks I'm rebuilding a 66 dodge charger its a huge learning experience for me I got it for my dad as a project for the both of us last summer but he sadly passed in March so now its up to me to figure out .. Thank you very helpful
Greetings...Devilicious...........Sorry to hear about your Dad, and, I surely do, know how that feels...........1966 Dodge Charger, you say, well, I know quite a bit about the older cars, so, if you need any help at all, just let me know about, as to, what condition, that you want the car to end up in, when, all's said and done, as in, is "it", just gonna be, a daily driver/not too fussy at all, or maybe, you want to keep "it", as factory original as possible, perhaps...???............I'm not sure, but maybe, the 1966, might have drum brakes, on all four wheels, and maybe, manual steering and manual brakes (not power assisted), possibly, etc...........So then, if Ya care to, just give me a shout, when-ever, with, what-ever, and, if I'm able to help You out, so be it...........Good luck, with your Resto (Restoration), or, what-ever it ends up be-in, that will put a smile on your face, and........till next time.........Be Safe, take care, and have a good one.
My 66 has power steering manual brakes drums all the way around and it's a 383 automatic at least it's supposed to be it currently has a 76 440 in it I bought a 67 383 from a 67 Coronet for 300 bucks I was told it knocks when it's cold which my dad told me at the time that sounds like a main bearing because the motor looks like it's been rebuilt it has an elderbrock high rise on it with chrome caps our guess is when they rebuilt it they didn't torque it down right..
Also I am trying to restore it to as close as it would have came out as Factory
carboxyhemoglobin
Greetings aerial wheel....Thanks for your Input (comment)....I'm guessing that the Word that you posted there, is the Rocket-Science Word for "Carbon Monoxide Poisoning", or, when a Person Inhales a Lethal, or, almost Lethal amount of "CO" (or, Carbon Monoxide, that happens to be One of the Gasses that results from a Vehicles Engine Exhaust)....When (Hopefully Not!) a Person Inhales too much "Carbon Monoxide", it gets into a Persons Blood Stream, and (from what I recall), it "Inhibits" (or, Prevents) the Blood from Absorbing "Oxygen!"....Or, in simple terms, a Person will, shall we say, "Suffocate", for the reason of an Inadequate (or, not enough) Oxygen in the Blood to Sustain "Life!"
That's the reason that I try to Always mention about "NEVER" having a Vehicles Engine Running with "CLOSED" Garage Doors!!!
"Always", and I repeat, "ALWAYS", have Plenty of "Ventilation" (Fresh Air) whenever your vehicles "ENGINE" is Running!!!
Best Place to have your Engine Running, is "OUTSIDE" with Fresh Air "Everywhere!!!"...and...Stay away from your "Exhaust Pipe/s", and any "Exhaust Flow" whatsoever, so I will be able to Talk to You, and, Not About You!!!
Take care, be Safe, and, have a good one.
precisely. once a persons hemoglobin becomes carboxyhemoglobin, they can no longer use the oxygen carried in their bloodstream. exhaust leaks and driving with the trunklid or rear hatch open can be dangerous as well. i'm sure you know the dangers, but i always take the opportunity to discuss this subject whenever possible. : )
aerial wheel
Greetings aerial wheel....Yes Sir, a Person can never be Too Careful when it comes to Anything, that can become "Lethal" (aka...Life Threatening) to any Human, Pet, Animal, etc.
Another thing to be very Aware of, is, during Winter, (if you get Snow where you live or travel), if a Person (driver), and any Additional Occupants in the Same Vehicle, happen to get "Stuck" in a "Snow Bank", "Snow Drift", or any Depth of "Snow" that Prevents the Vehicles "Exhaust" from Venting completely away from said vehicle, then, the "Potential" for that Vehicles Exhaust Gas to get Trapped "Underneath" the Vehicles "Chassis" (Frame, or Under-Carriage), makes it Possible for that Vehicles Engines "Trapped" Exhaust Gas to "Enter" the Vehicle from "Underneath", and "Enter" the "Passenger Compartment", making it "Extremely-Life-Threatening", and "Lethal" in some cases, to the Vehicles Occupant/Occupants!!!
Who knows, perhaps Somebody who has, or is reading these Words here, and now, might "Save" their Own Life, but, "Other" Lives as well, if they, or, they see Other People that might just be..."Stuck" in some "Deep" Snow.
Take (Extra) care, and, have a good one.