This video is about a decade old now, and it's still awesome. Teaching how the system worked helped me fix my old F-250 with an IAC problem. Paul Danner, you do a great service in teaching and producing high quality video content. Thank you. From one teacher to another, keep spreading the knowledge!
It’s a lot easier to diagnose an issue when you know how it’s supposed to operate and what variables play into it. Helped me with me old f-250 as well!
I promise you can. I film live and tell it like it is. I can be long winded sometimes but I've been a teacher for 20 years at a technical college, so I can't, not, teach 😉 It's just part of me now. Thank you!
@@ScannerDanner My 98 crown victoria has a problem of AC compressor turning on and off every 5 to 8 seconds even on heating cycle. Can you tell me what is the problem, and how to fix it?
@@KunioMasuda two things: 1. It sounds like you are low on refrigerant charge. The compressor will "short cycle" when it is low. 2. Ford systems in your year will run the AC compressor (even in the heat mode) in all positions except floor and maybe panel vents. This is done to dehumidify the air for defogging reasons.
@@ScannerDanner My 98 crown vic had some shaking at idle, so I cleaned IAC valve, MAF sensor pcv and EGR valve and also injected Sea Form into throttle body. This took care of the shakes at idle, but decided to change all these item to new ones since my car has over 200k miles. Then the new IAC valve made a loud humming noise. So I returned this new IAC for refund. And put back the old one. Now the engine is very quiet. But I'll buy another new one to replace it for my sense of security. I'm about to replace O2 sensors also. Can you recommend what else I should replace to maintain this crown vic in good conditions? Thanks, Kunio
I've heard of city/maintenance employees turning the idle higher because they do a lot of task the require the vehicle to go about 10 mph. High idle does that perfectly.
Saved my ass. I just bought a 98 f150 with the 4.6, started replacing OE consumables, after all that it still had a high idle and throwing p1507. I was thinking I could have a bad intake manifold or something but, I did exactly what you did in this video (with a cheap scan tool- has live data), and sure as shit fixed me up nice. Previous owner must have tried to fix the fact that he didn't do any maintenance on the truck, by turning that screw in. Thanks.
I learned so much from you! Here in my country they are at least 15 years behind you in dignostic. It's about method and understanding the whole picture how engine works. Thank's so much!
Hi I have had a fast idle problem for some time on an old Hyundia Atos. After watching lots of vids on youtube and studying the manual I still was not getting anywhere,but...when I followed your simple method as shown in your vid HEY PRESTO, Perfection my car is idling absolutely spot on. I can't thank you enough for for making an instructional vid that actually works and took me 5 mins to fix the problem with a pair of long nose pliers. 1000 thank you's:) John C Liverpool UK
In my case I had a 2002 f150 4.2 and the throttle body was bent from the piece that turns the tps so it was advancing the sensor to a higher voltage this guy gave me a clue because my tps voltage was 1.8v which was high. I bent the piece back and done, I had already checked every possible vacuum leak and I finally fixed it...thanks dude you are awesome!! Keep up the great work
99 Mustang v6. Throttle was hanging bad between shifts at 2 or 3k RPM. Replaced IAC and TPS and still had issues. With the IAC unplugged I backed off the blade screw on the throttle body till the RPMs dropped to 500 as described in this video. Plugged IAC back in and idle came up to around 650 or so and solved the hanging RPM problem. IAC now controlling throttle as it should. Apparently someone messed with the screw. Great video!!! Thank you.
Nailed it! Thank you very much. I had a stalling problem on my Ford that I couldn't figure until I saw your video. My numbers were just the opposite of these... TP(V) was just 0.86 and the IAC(%) was at 52. I realized the IAC was overworking to keep the idle at the desired RPM, and I had the room to play with the throttle position. I felt like I knew what I was doing!
The answer lies within the TPS learned closed throttle position. Once the PCM "re-zeros" the TPS, it will then try to correct idle speed. As long as the PCM "thinks" your foot is on the pedal it WILL NOT try to control idle speed, in fact it actually opens up the IAC during this condition to prepare for decel. Hope that makes sense.
What is the ideal idle speed of Ford Expedition 4.6 L ? My Expy is always at 800rpm in park and in drive mode,If it is lower than 800 rpm it shake but never dies.So I just don't bother anymore after I replaced theIAC.
Ok, it’s 11pm here in Oregon and I think your way east, you should be way asleep not responding to comments 🙈 But thanks. I’ve been fighting with this Camry 4 cylinder after I replaced just about every seal in the motor including replacing the distributor. Runs great but after long sustained drives and pulling off freeway it would super slow idle then die. Turned out to be sticking Egr valve was slow to close. Only realized this after speeding idle up with throttle stop screw. Seeing this video it makes sense. I should be slapped with a wet vacuum hose. I even have the big factory Toyota service Manuel so no excuses 🤐
2000 Ford F150 5.4L my truck. Cold outside, truck will turn over but not start after 3,4,5,6,7 tries. When started, it ran like crap until heated. Replaced IAC. Fixed. Was easier than filling the windshield wash reservoir. Ford mechanics in all the forums said "Do this first, cheapest solution and 99% THE solution"
This is an excellent question! All I can think of is that computer must be very smart to realize that the minimum idle it has observed for last many starts was higher than expected. Otherwise you are right, the code would be there any time you hold your feet on the gas e.g. say warming up the engine faster for some tests. It is a great question and I hope Paul answers it.
Im trying to fix a 92 mustang lx and you gave me some ideas I didnt read from another person. My mustang wont start now but it was starting at 900rpm the last time (like 4 or 5 times it was starting just fine at 900rpm because I "adjust" TPS because low rpm). I think my problem is going that direction you said. Sometimes comments enlight us. I will comment later when I try it. Thank you man
I paused at 4:00. IAC appears to work fine, but I see the throttle position sensor is 1.14, if the tps is reading above 1.0 volt it results in higher than desired idle.
Clearly the customer adjusted the throttle plate to compensate for a potentially dirty throttle body. But the previous shop could have performed a visual inspection to have possibly revealed the root cause of the concern (throttle adjustment screw tampering). Customers/car owners do not always reveal their mistaken misdiagnosis/repair attempts until thoroughly questioned. As technicians we also wear the hat of Crime Scene Investigator's to weed through the clues & details before the repair.
Great video, learned a lot from it. I checked some of your items, but nothing as yet will reduce my 1300 idle rpm. 1997 Taurus, replaced IAC twice, meter checked TPS, idle set screw correct, MAF cleaned twice, vacuum hoses checked, PCV replaced and even did a smoke test. Only smoke I could find was coming out the body of the IAC around the body ring, not base plate. Cleaned throttle body, checked and it is closing, sprayed break cleaner and nothing changed looking for air leak.
normal to see smoke come out of the IAC vent. Disconnect the MAF (make sure the electrical connector is unplugged to put it in default mode. Remove air intake tube, find the IAC inlet hole in front of the throttle plate and block it with your finger. Does your idle drop or stay the same?
ScannerDanner Ok, unplugged MAF, removed Air Intake Tube, removed Hose infront of and below IAC. This hose had a dbl clamp on it, short hose and 90 then went over to another vacuum control box where the BB hose goes. Plugged pipe and engine RPM came down to 900 - 1000, but engine ran very rough and could hear a pop or missfire, but did not stall. Put it all back together and ran at 1300 RPM. Thanks Scanner Jerry
ScannerDanner Pulled IAC, blocked both opennings and no change in idle. Tried blocking one and still no change. Pinched all vacuum lines and barely a noticable change in idle speed. No change when pinching BB vacuum line. Since I can find nothing else, I am thinking maybe vacuum leak under manifold. Didn't get any reaction spraying brakekleen, but maybe it's just not reaching leak. Thoughts?
jhaskins0256 It's rare, but exhaust leaks can look like vacuum leaks. Before the upstream(s) O2 sensor, if there's a leak, the engine will think it needs more fuel to compensate for a problem and it'd be running richer than it thinks it really is.
have you checked your ignition? a weak ignition will oftentimes cause a car to compensate to a higher rpm. that or straight vacuum leak as you are looking for. I just did a ranger where the fuel filter was nearly plugged and it resulted in a lean condition and high idle.
good video! And this probably can help someone KOEO closed Throttle voltage should be 0.7 to 1.1 volts and by the process that you show in the video you get it at 1.1 volts that's just perfect! And by using Scanner DATA process! Very good direction how too address this situation!
Hi Paul, on ones I have done in the past if someone messed around with the idle screw, I would clean the throttle plate etc with carb clean, and I would unwind the screw so the plate was shut, then screw it in so it just touches, or possibly in 1/4 after it touches and try it there, Fords here used to be 0.7 volts on Potentiometer,,,Fred uk.
so the valve is normally closed. no air at all goin in thru. so you unplug it and set the throtlevalve to 500rmp then plug the iac in and the computer adjust the valve. So if I unplug the valve with the engine running I should feel no air entering the air ports that feed the valve? if I do feel vacuum on the ports the valve is defective or not closing and needs changed out? I know the valve is clean , I know it moves , but I don't know if it closes all the way .
cleaning the throttle plate does allow more airflow with the throttle closed but this would not have changed the TPS angle or helped the situation at all. If anything it would have made it worse. (an even higher idle speed)
not sure. the question is, Is the rising and falling IAC count the cause of the rolling idle or is it an effect of the rolling idle. My guess is it is the latter. I doubt it is a faulty IAC valve. They simply do not fail in this way. I would look close at those timing marks.
So, like, you need a computer now to tell you your idle screw is set too high/low? 😆I just need someone to do it for me! It's a fantastic demonstration of troubleshooting though. THANK YOU!
Thanks for the great video. I have a 1997 Ford F 250 PU with a 7.5 L gas engine that just started "today" having low idle issues. I will check vacuum lines first, anything else you can suggest that a rookie with very little money can check?
Very informative. I am having possibly the same issue. My truck recently started doing the opposite when coming to a stop. Rpm would go down to 350rpm or so and eventually stall the truck. I have a 2001 Ford F250 V10. I have a scan tool and its showing my IAC% around 36% at idle. Engine is idling around 650-700rpm. When I unplug the IAC sensor I can hear the idle drop, but they only drop about 100rpm and the IAC shows 49% when I unplug the sensor to the IAC. I am using an SCT X5 scanner to view the IAC data. I replaced the IAC with a new IAC yesterday before seeing your video in hopes it would fix my issue and it did not resolve the issue. Engine is brand new, new PCV, new IAC, new fuel filter, new spark plugs. Throttle body base screw looks stock, never been moved. I notice at the end of your video your IAC % is the same as my truck around 36%. Thanks Scanner Danner! I find your information always very helpful!
+Kendall Huseman I checked my voltage on the TPS with Key On Engine Off and it is at .99v. I disconnected the IAC and the idle dropped. I then blipped the throttle a few times and the truck would rev but about the 2nd or 3rd rev the truck idled so low that it stalled out. Does this help at all? It's seeming like the computer/tps or something is not adjusting quickly enough. I do not have an EGR on this vehicle.
will IAC counts on a GM valve moving up/down, corresponding with rising and falling engine load %, indicate a bad IAC or the computer controlling (or trying to) the IAC in response to perceived changes in engine load? tried a map sensor since it's a speed density system, no change. 2.2 ecotec, just did the timing chain. has good compression but wandering idle. no vac leaks, P0507 code. i suspect the IAC.
hey ScannerDanner i have a 4.6 2v i adjusted my idle like you showed here ,everything is good but one thing ,when i put car in drive it tends to dip little low but reversr is good, should i raise idle just a tad more or?
On my 94 Ford Explorer the idle is all over the place and I hear what sounds like miss fire and the rpm spikes and lowers to around 700. And when I unplug my IAC the idle goes down to 500 rpm and the engine seems to run better and no missfire sound. Bad iac?
I got an 01 explorer w/4.0 and didn't develop high idle till changing throttle body gasket and cleaning throttle plate, i did do a check of tps volts and its at 1.2 v. I'm gonna give this a try. I have code P1506 but already put new iacv a month ago.
That's not what you want, rather you want the ECU to be able to make slight adjustments in differing idle load states such as battery charge or A/C cycling, other electrical load, etc while the throttle plate at idle is just that, a fixed value that won't change with the load. BOTH your throttle body and your IAC should be clean for good operation.
So from a customer perspective here...is what you indicated about the numbers information on your scan tool sufficient to leave things as you being content with those numbers from diagnosing issue to charge customer given its not completely where it should actually be???
S/D I have a 99 crown Victoria I replace the TPS now I have a real high idle that doesn't come down at all even after driving it the idle is still high like a carburetor car
Is the TPS adjustable? What is your closed throttle or idle TPS voltage? If it is not adjustable, TPS min voltage is a learned value and may need the battery disconnected to reset it.
You do not need the professional equipment I use to do this. There are many options for the DIYer and this information transfers directly to lower cost scan tools and scopes.
There are code readers for OBD1 cars, but the popular scanners apply to OBDII systems, as installed in some '95 FOMOCO cars and ALL cars made in '96 and later.
I've seen the idle air control on a new edge Mustang v6 with no idle issues at around 52%. No stalling while decelerating or any other engine performance issues. Idle RPM is at spec. (between 700-730). Near the end you stated that this could potentially be an issue, can you elaborate on that? Maybe if I was stopped at a red light, uphill.
Anytime someone adjust one of those idle screws to compensate for a closed IAC there is an easy easy way to reset those idle screws.take off the air cleaner assembly at the throttle intake opening and just slide it over to the right. Now (without engine running) Look at the throttle plate valve and open the the throttle and close it. You should hear metal hit metal, if you don't then keep unscrewing idle crew until the throttle plate touches the cylinder opening. When the plate JUST TOUCHES the metal then that is where it goes! Then if it wont idle after starting its your IAC. When people turn those idle screws up they are bypassing a closed IAC is what theyre doing, but what is sad is that they think it is fixed. It wont hurt anything other than the engine might sie a few times at cold start up but a person can get by that way until they change that IAC
humm, im trouble shooting a 99 windstar 3.8L, that idles rough and stalls at stops when in gear,runs smooth when accelrating or staying at street/highway speeds, the IAC is clean and working, EGR working, new DPFE, only codes 171 & 174 bank 1 bank 2 lean, throttle plate in correct position, ran good on July 1, several days later upper hose leaked and engine overheated vehicle is Not mine, current 3rd owner recently acquired it, 183670.xx miles
Hi Paul - what if you have a third and fourth variable - an adjustable TPS and also a throttle body like the one you showed, plus it also has an air screw that you can turn clockwise or counterclockwise? I'm confused where to even start as the baseline here. (Ford probe, EEC-IV)
No engine light but idle fluctuates in Park only, As soon as I put it to reverse and then drive it is back to perfect idle at 750rpm. What is the problem, should I just ignore it?It runs fine in Drive and on all stops.
07 Ford tarsus stalls at lights or in park. I changed the iac and cleaned the throttle body and it didn’t help any. I bought a obd2 got a code for the idle air control circuit, cleared the code it hasn’t came back but still stalls I need some help
Hey Danner, i have a 2004 Ford Focus mk1 1.6 16v petrol. i have a problem with the idle, if the engine is warm, when I'm driving, and when I need to shift and press the clutch the idle drops to about 500 rpm than it raises to the normal idle speed and stabilize.And I've noticed that the car doesn't stay idle when letting it rolling in its 1st or 2nd gear. It stutters and keeps it with lots of work at normal idle speed. The car remains with a lot of trouble rolling, and does not fall out. But as soon as I move up a bit, the speed drops very low, and stutters but the car doesn't fall out. i already replaced the idle air control with a new one aftermarket Pierburg. i alread have reset the ecu 1 day disconnecting from battery and let is warm up at first start. also i have cleaned out the throttlebody and replaced the tps. The car idles very smooth when cold or warm and does not move any inch. once a week the car starts hard and stutters. The car drives very good and has lots of power. im lost and dont know what to do for this problem danner. Can you give me a suggestion pls ?
Hi Paul at 1:57 you mentioned not knowing if it had a EGR flow problem because someone cleared the trouble codes, what effect would a EGR flow problem have on the IAC?
I only mentioned that as a guide to the technician who is selling the job, to make no promises about the check engine light, because someone just cleared the codes before it was looked at. So other problems could exist. That's all. It was a cover your ass statement. An EGR flow (restriction) would have zero effect on idle speed and IAC function
That screw is even made in a way so you can't mess with it, since it has no head or anything. That should be indication enough that they don't want you to mess with it. xD Man scan tool is useful if you know what you're doing and know what you're looking at. Very cool stuff for sure. I just wish I went to school for a technician. But hey, I can learn a bit this way too. :) I'll buy your book when I have bit more money, it's tough over here lately... Do you ship worldwide? Would love a hard copy if they are available.
i need to set my idle just 100 points higher to compensate for a weak oil pump. just 100 points will do. how do i do that on a 2002 ford ranger, 3.0 n??? i tried the screw, but the computer resets it
This is why I now have a 2011 Leaf EV, I'm going all electric vehicles in the future, and I recommend everyone do the same. Sorry, but I'm so done with overly complicated smogged up ICE vehicles. I'm fighting now with a IAC on my '92 40ft motorhome with a 460efi and I'm frustrated, confused, and pist off. Likely got a bad new IAC complicating the fix. New one leaks vac slightly with power disconnected. SO DONE.....bad parts from suppliers etc etc SO DONE.
Scanner Danner I have a 2001 and the code is P0351 means = # cylinder coil. now this is the second coil pact I'v replace in about 4 months. I did have the intake replaced because it was the recalled one and it finally cracked and leaked. everything ran great for months and then I replaced the # 4 cylinder and now it wants me to replace the #1. I have been having stall issues and this is prior to the # 4 cylinder replaced coil pack. I'm thinking it could be the crankshaft position sensor.. Whats your take? thanks. I watch you with Eric the car guy and I love the scanners you have. I just have the OBDII code finder. Nothing more. Have a good one.
I need to be able to manually control my IAC to spin up my alternator to generate more power, but I don't have a stepper motor style IAC, it has this duty cycle version, does that mean I need to manual add more or less voltage to the IAC to get it to open more?
Thanks brother. I changed the oil after I had a coil misfire and replaced the coils and plugs. I am still getting rich post cat 02s on both sides. Did a injector balance test and they are all good dropping from 45 down to 22 on all 8 cylinders. Have 39 to 45psi fuel pressure at idle and have all four cats new, Walker, as the Ford cats were $2500 dollars for all four. Put all four Motorcraft 02s also. Has me stumped.
P0505 for 99 Durango(check engine also). Replaced I.a.c several times to no avail. Checked for vaccuum leaks, didn't sem to find any. Any ideas?! Been this way for over 1 year and emmissions is coming up real soon.
Hello and thank you for the video. Question, I did exactly as you said. At one time the idle plate was adjusted. I disconnected the IAC and the rpm jumped from 11k to about 14k. I unscrewed so the plate would close more but there was no change. According to the book my rpm should be at 700 idle. I added sandwich bag around the IAC to make sure there was no air being sucked in that area but still no change. I plugged the IAC and the RPMs dropped to about 11k again. I've cleaned the idle plate and body too. Can you think of what my next step should be? Thank you
I have a 1997 Ford Expedition XLT 4.6 that misfires on one cylinder due to low idle at 550 rpm. No misfire at 650. Can’t pass inspection. Can the rpm be raised a bit?
Still not sure how this can help. My 95 Ranger's idle speed gradually increased over a few days from 2000 to 3000, really screaming. Changed IAC valve, also found a crack in intake manifold, letting air in. Sealed crack, engine still screams. Ideas?
Hello everyone! I am not a professional mechanic at all just a man trying to help my wife's cousin who is a single mother. She has a 2002 Ford Taurus V6 engine. Car would run only if you would keep your foot on the throttle as soon as you would take it off it would stall. I replaced the ICV and it looks like the stalling issue is fixed but it seems to now be running just a little lean approx. 800-900 RPM kind of moves up and down a little! When I removed the old ICV the inside was filthy and she is not the best at maintaining the vehicle and not sure if the previous owner was either. Any help with the low RPM would really be appreciated. Have a wonderful week. -Paul
Hey there... please help. My 2002 e250 van (cng) has a low idle this problem is new. It was fine then I just didn't drive the van for a long time the battery died when I jumped now it has a low idle. Ok. Im thinking that when the battery died it erased the position of the idle from the computer now the van is confused and doesn't know the correct idle position?!?!?!?! I'm so confused on what to do!!!!!
Looking at my scanner-live data, i only see RPM at drive (650) and RPM at neutral(750) , is RPM at drive the same for desire RPM IDLE? . I keep getting a buzing noise coming from the air tube that the iac valve is sucking air from.
roberto ortiz desired RPM is what the computer wants the car to run at. RPM should match Desired RPM. The buzzing sound you are describing could be a cracked bellows on the IAC valve itself. Older Fords had this issue. And it would also give you a higher than normal RPM at times. Pull the IAC off and look inside of it. Is there a plastic bellows inside of it? If so, gently look between the ridges of the bellows with a small pocket screwdriver, you will see the cracks.
Sir, I had to adjust my low idle rpm , and i fixed it by adjusting the Throttle stop screw, and it also worked. But then heard there's another screw called Idle Air Adjustment Screw, which is there specially for this purpose of adjusting idle air flow? and that the Throttle stop screw should not be changed but instead the idle air adjustment screw should be adjusted? I'm really having this confusion which one should i be adjusting and what are the difference between.these two?
IF you have an idle air adjustment screw, this should have been the one you adjusted. Most systems, all you need to do is to clean the throttle body to restore minimum idle speed.
This video is about a decade old now, and it's still awesome. Teaching how the system worked helped me fix my old F-250 with an IAC problem. Paul Danner, you do a great service in teaching and producing high quality video content. Thank you. From one teacher to another, keep spreading the knowledge!
Thank you!
It’s a lot easier to diagnose an issue when you know how it’s supposed to operate and what variables play into it. Helped me with me old f-250 as well!
"Don't touch that screw unless you know what you are doing!".. well, thanks to you we do know now :) Another great video, thank you.
Judging from his confident voice, I can tell he is a one of a kind mechanics that I can trust.
I promise you can. I film live and tell it like it is. I can be long winded sometimes but I've been a teacher for 20 years at a technical college, so I can't, not, teach 😉
It's just part of me now. Thank you!
@@ScannerDanner
My 98 crown victoria has a problem of AC compressor turning on and off every 5 to 8 seconds even on heating cycle.
Can you tell me what is the problem, and how to fix it?
@@KunioMasuda two things:
1. It sounds like you are low on refrigerant charge. The compressor will "short cycle" when it is low.
2. Ford systems in your year will run the AC compressor (even in the heat mode) in all positions except floor and maybe panel vents. This is done to dehumidify the air for defogging reasons.
@@ScannerDanner Thank you very much for your professional advice.
@@ScannerDanner
My 98 crown vic had some shaking at idle, so I cleaned IAC valve, MAF sensor pcv and EGR valve and also injected Sea Form into throttle body.
This took care of the shakes at idle, but decided to change all these item to new ones since my car has over 200k miles.
Then the new IAC valve made a loud humming noise. So I returned this new IAC for refund. And put back the old one.
Now the engine is very quiet. But I'll buy another new one to replace it for my sense of security.
I'm about to replace O2 sensors also.
Can you recommend what else I should replace to maintain this crown vic in good conditions?
Thanks,
Kunio
I can feel the Passion in this Gentleman! Awesome professor!
thanks man, I really do love my job and I love to teach.
This mechanic knows his stuff.Great video!
Haynes manual would not go into this but you did and now my idle is set right THANK YOU!!!
I've heard of city/maintenance employees turning the idle higher because they do a lot of task the require the vehicle to go about 10 mph. High idle does that perfectly.
Saved my ass. I just bought a 98 f150 with the 4.6, started replacing OE consumables, after all that it still had a high idle and throwing p1507. I was thinking I could have a bad intake manifold or something but, I did exactly what you did in this video (with a cheap scan tool- has live data), and sure as shit fixed me up nice. Previous owner must have tried to fix the fact that he didn't do any maintenance on the truck, by turning that screw in. Thanks.
I learned so much from you! Here in my country they are at least 15 years behind you in dignostic. It's about method and understanding the whole picture how engine works.
Thank's so much!
Great comment. It helps seeing it through their eyes
Hi I have had a fast idle problem for some time on an old Hyundia Atos. After watching lots of vids on youtube and studying the manual I still was not getting anywhere,but...when I followed your simple method as shown in your vid HEY PRESTO, Perfection my car is idling absolutely spot on. I can't thank you enough for for making an instructional vid that actually works and took me 5 mins to fix the problem with a pair of long nose pliers. 1000 thank you's:) John C Liverpool UK
In my case I had a 2002 f150 4.2 and the throttle body was bent from the piece that turns the tps so it was advancing the sensor to a higher voltage this guy gave me a clue because my tps voltage was 1.8v which was high. I bent the piece back and done, I had already checked every possible vacuum leak and I finally fixed it...thanks dude you are awesome!! Keep up the great work
very helpful and easy to follow i could listen to you teach for hours!
+Bill Thacker thanks man! you're in luck, between my 2 channels I have hundreds of hours of training material :-)
This Guy is a "MASTER" at this !!!!!
Foto Guy Watch Eric at South Main Auto!
99 Mustang v6. Throttle was hanging bad between shifts at 2 or 3k RPM. Replaced IAC and TPS and still had issues. With the IAC unplugged I backed off the blade screw on the throttle body till the RPMs dropped to 500 as described in this video. Plugged IAC back in and idle came up to around 650 or so and solved the hanging RPM problem. IAC now controlling throttle as it should. Apparently someone messed with the screw. Great video!!! Thank you.
awesome!
IAC restrictor plate solved my hanging rpm between manual shifts. Make sure to position the smaller hole opposite the IAC plug in.
I've seen a lot of your videos and this one I think is the best video you have posted in a while. Thanks for sharing with us
Nailed it! Thank you very much. I had a stalling problem on my Ford that I couldn't figure until I saw your video. My numbers were just the opposite of these... TP(V) was just 0.86 and the IAC(%) was at 52. I realized the IAC was overworking to keep the idle at the desired RPM, and I had the room to play with the throttle position. I felt like I knew what I was doing!
The answer lies within the TPS learned closed throttle position. Once the PCM "re-zeros" the TPS, it will then try to correct idle speed. As long as the PCM "thinks" your foot is on the pedal it WILL NOT try to control idle speed, in fact it actually opens up the IAC during this condition to prepare for decel.
Hope that makes sense.
What is the ideal idle speed of Ford Expedition 4.6 L ? My Expy is always at 800rpm in park and in drive mode,If it is lower than 800 rpm it shake but never dies.So I just don't bother anymore after I replaced theIAC.
wish I'd seen this video 8 months ago, I touched the screw on my 94 Toyota Camry. will now go and do the baseline idle adjustment.
Clean the throttle body first. Block the IAC passage (varies on type of valve and system) then set your base idle screw to around 400-500 RPM
Ok, it’s 11pm here in Oregon and I think your way east, you should be way asleep not responding to comments 🙈
But thanks.
I’ve been fighting with this Camry 4 cylinder after I replaced just about every seal in the motor including replacing the distributor. Runs great but after long sustained drives and pulling off freeway it would super slow idle then die. Turned out to be sticking Egr valve was slow to close. Only realized this after speeding idle up with throttle stop screw.
Seeing this video it makes sense.
I should be slapped with a wet vacuum hose.
I even have the big factory Toyota service Manuel so no excuses 🤐
lol, late night beer league ice hockey game, can't sleep for hours after
2000 Ford F150 5.4L my truck. Cold outside, truck will turn over but not start after 3,4,5,6,7 tries. When started, it ran like crap until heated. Replaced IAC. Fixed. Was easier than filling the windshield wash reservoir. Ford mechanics in all the forums said "Do this first, cheapest solution and 99% THE solution"
This is an excellent question! All I can think of is that computer must be very smart to realize that the minimum idle it has observed for last many starts was higher than expected. Otherwise you are right, the code would be there any time you hold your feet on the gas e.g. say warming up the engine faster for some tests. It is a great question and I hope Paul answers it.
Im trying to fix a 92 mustang lx and you gave me some ideas I didnt read from another person. My mustang wont start now but it was starting at 900rpm the last time (like 4 or 5 times it was starting just fine at 900rpm because I "adjust" TPS because low rpm). I think my problem is going that direction you said. Sometimes comments enlight us. I will comment later when I try it. Thank you man
I was just trying to fix my ford with same problems. Going to try your method and hops I fix it! Thanks for your video!!
absolutely correct on that one
I paused at 4:00. IAC appears to work fine, but I see the throttle position sensor is 1.14, if the tps is reading above 1.0 volt it results in higher than desired idle.
It certainly can on some cars.
anytime, glad you liked it, thanks
Glad i learned something today in case my van has a issue again
man I really wish I had you here fixing my truck dude I have a serious high idle problem and I cannot figure out what it is driving me crazy
Clearly the customer adjusted the throttle plate to compensate for a potentially dirty throttle body. But the previous shop could have performed a visual inspection to have possibly revealed the root cause of the concern (throttle adjustment screw tampering). Customers/car owners do not always reveal their mistaken misdiagnosis/repair attempts until thoroughly questioned. As technicians we also wear the hat of Crime Scene Investigator's to weed through the clues & details before the repair.
Great video, learned a lot from it. I checked some of your items, but nothing as yet will reduce my 1300 idle rpm. 1997 Taurus, replaced IAC twice, meter checked TPS, idle set screw correct, MAF cleaned twice, vacuum hoses checked, PCV replaced and even did a smoke test. Only smoke I could find was coming out the body of the IAC around the body ring, not base plate. Cleaned throttle body, checked and it is closing, sprayed break cleaner and nothing changed looking for air leak.
normal to see smoke come out of the IAC vent.
Disconnect the MAF (make sure the electrical connector is unplugged to put it in default mode. Remove air intake tube, find the IAC inlet hole in front of the throttle plate and block it with your finger. Does your idle drop or stay the same?
ScannerDanner Ok, unplugged MAF, removed Air Intake Tube, removed Hose infront of and below IAC. This hose had a dbl clamp on it, short hose and 90 then went over to another vacuum control box where the BB hose goes. Plugged pipe and engine RPM came down to 900 - 1000, but engine ran very rough and could hear a pop or missfire, but did not stall. Put it all back together and ran at 1300 RPM. Thanks Scanner
Jerry
ScannerDanner Pulled IAC, blocked both opennings and no change in idle. Tried blocking one and still no change. Pinched all vacuum lines and barely a noticable change in idle speed. No change when pinching BB vacuum line. Since I can find nothing else, I am thinking maybe vacuum leak under manifold. Didn't get any reaction spraying brakekleen, but maybe it's just not reaching leak. Thoughts?
jhaskins0256 It's rare, but exhaust leaks can look like vacuum leaks. Before the upstream(s) O2 sensor, if there's a leak, the engine will think it needs more fuel to compensate for a problem and it'd be running richer than it thinks it really is.
have you checked your ignition? a weak ignition will oftentimes cause a car to compensate to a higher rpm. that or straight vacuum leak as you are looking for. I just did a ranger where the fuel filter was nearly plugged and it resulted in a lean condition and high idle.
good video! And this probably can help someone KOEO closed Throttle voltage should be 0.7 to 1.1 volts and by the process that you show in the video you get it at 1.1 volts that's just perfect! And by using Scanner DATA process! Very good direction how too address this situation!
Heck yeah! Good additional info.
Hi Paul, on ones I have done in the past if someone messed around with the idle screw, I would clean the throttle plate etc with carb clean, and I would unwind the screw so the plate was shut, then screw it in so it just touches, or possibly in 1/4 after it touches and try it there, Fords here used to be 0.7 volts on Potentiometer,,,Fred uk.
not unless you were watching IAC position too. You could match desired and actual rpm but have the IAC way out of position to achieve it.
so the valve is normally closed. no air at all goin in thru. so you unplug it and set the throtlevalve to 500rmp then plug the iac in and the computer adjust the valve. So if I unplug the valve with the engine running I should feel no air entering the air ports that feed the valve? if I do feel vacuum on the ports the valve is defective or not closing and needs changed out? I know the valve is clean , I know it moves , but I don't know if it closes all the way .
cleaning the throttle plate does allow more airflow with the throttle closed but this would not have changed the TPS angle or helped the situation at all. If anything it would have made it worse. (an even higher idle speed)
not sure. the question is, Is the rising and falling IAC count the cause of the rolling idle or is it an effect of the rolling idle. My guess is it is the latter.
I doubt it is a faulty IAC valve. They simply do not fail in this way.
I would look close at those timing marks.
How much does this cost at a shop? Thanks for the great video.
Thanks so mucho, I was looking for this video for years, CONGRATULATION
So, like, you need a computer now to tell you your idle screw is set too high/low? 😆I just need someone to do it for me! It's a fantastic demonstration of troubleshooting though. THANK YOU!
Thanks for the great video. I have a 1997 Ford F 250 PU with a 7.5 L gas engine that just started "today" having low idle issues. I will check vacuum lines first, anything else you can suggest that a rookie with very little money can check?
thank you this will help me with my ford ranger
+Jorge Estevez thank you!
Thank you for a great video and wonderfully detailed explanation.
Glad it was helpful!
Excellent video !!!!👏😎
Best video ever
What causes stalling in reverse and drive in my 93 f150 5.0
I wish this guy could have a look at my idle air control valve. My mechanic has 40 years of experience and could not fix it.
it is very possible you do not have an IAC issue. What is it doing?
Can that make the car run bad to if you touch that adjust screw?
Only idle issues, not really "run bad" issues. Too high or low of an idle speed and off throttle stalling would be your only symptoms
See my car keeps getting hot and trying to go when I stop to a red light but my temperature gauge says good
Good info..
My Lincoln 4.6 has a slight idle surge at stop when not under load. Any ideas?
Have you figured out the issue ?
@@THESMOOVEGAMER
Yea think was dirty map sensor
Very good video broke it down quick.
Wow I just learned so much...Thank you
Thank you for watching!
Fantastic video!
Very informative. I am having possibly the same issue. My truck recently started doing the opposite when coming to a stop. Rpm would go down to 350rpm or so and eventually stall the truck. I have a 2001 Ford F250 V10. I have a scan tool and its showing my IAC% around 36% at idle. Engine is idling around 650-700rpm. When I unplug the IAC sensor I can hear the idle drop, but they only drop about 100rpm and the IAC shows 49% when I unplug the sensor to the IAC. I am using an SCT X5 scanner to view the IAC data.
I replaced the IAC with a new IAC yesterday before seeing your video in hopes it would fix my issue and it did not resolve the issue. Engine is brand new, new PCV, new IAC, new fuel filter, new spark plugs. Throttle body base screw looks stock, never been moved.
I notice at the end of your video your IAC % is the same as my truck around 36%.
Thanks Scanner Danner! I find your information always very helpful!
+Kendall Huseman
I checked my voltage on the TPS with Key On Engine Off and it is at .99v. I disconnected the IAC and the idle dropped. I then blipped the throttle a few times and the truck would rev but about the 2nd or 3rd rev the truck idled so low that it stalled out. Does this help at all? It's seeming like the computer/tps or something is not adjusting quickly enough. I do not have an EGR on this vehicle.
+Kendall Huseman start by cleaning the throttle body
Paul,
Awesome video once again.
Pete
.o k b
ol .ii.8
will IAC counts on a GM valve moving up/down, corresponding with rising and falling engine load %, indicate a bad IAC or the computer controlling (or trying to) the IAC in response to perceived changes in engine load? tried a map sensor since it's a speed density system, no change.
2.2 ecotec, just did the timing chain. has good compression but wandering idle. no vac leaks, P0507 code. i suspect the IAC.
hey ScannerDanner
i have a 4.6 2v i adjusted my idle like you showed here ,everything is good but one thing ,when i put car in drive it tends to dip little low but reversr is good, should i raise idle just a tad more or?
Very intuitive I fully understand this now and it makes since.
Is this cold start up ? What should the cold start be ? Rpm
depends heavily on the temp and the car you are working on
On my 94 Ford Explorer the idle is all over the place and I hear what sounds like miss fire and the rpm spikes and lowers to around 700. And when I unplug my IAC the idle goes down to 500 rpm and the engine seems to run better and no missfire sound. Bad iac?
thank you
I got an 01 explorer w/4.0 and didn't develop high idle till changing throttle body gasket and cleaning throttle plate, i did do a check of tps volts and its at 1.2 v. I'm gonna give this a try. I have code P1506 but already put new iacv a month ago.
Very interesting, thanks!
Great video, thanks!!!
Would have cleaning the throttle plate reduced the TPS voltage and allow more airflow at idle?
That's not what you want, rather you want the ECU to be able to make slight adjustments in differing idle load states such as battery charge or A/C cycling, other electrical load, etc while the throttle plate at idle is just that, a fixed value that won't change with the load. BOTH your throttle body and your IAC should be clean for good operation.
thank you!
So from a customer perspective here...is what you indicated about the numbers information on your scan tool sufficient to leave things as you being content with those numbers from diagnosing issue to charge customer given its not completely where it should actually be???
I'm guessing you also do this adjustment when the engine is fully up to temperature too?
S/D I have a 99 crown Victoria I replace the TPS now I have a real high idle that doesn't come down at all even after driving it the idle is still high like a carburetor car
Is the TPS adjustable? What is your closed throttle or idle TPS voltage?
If it is not adjustable, TPS min voltage is a learned value and may need the battery disconnected to reset it.
Thanks for the lesson bro!😀
Thank you, i'll fix mine today.
Most of us don't have the fancy car computers that you have...
You do not need the professional equipment I use to do this. There are many options for the DIYer and this information transfers directly to lower cost scan tools and scopes.
Can you use scan tools on Obd1 cars?
harley Rider a
harley Rider qq
There are code readers for OBD1 cars, but the popular scanners apply to OBDII systems, as installed in some '95 FOMOCO cars and ALL cars made in '96 and later.
I've seen the idle air control on a new edge Mustang v6 with no idle issues at around 52%. No stalling while decelerating or any other engine performance issues. Idle RPM is at spec. (between 700-730). Near the end you stated that this could potentially be an issue, can you elaborate on that? Maybe if I was stopped at a red light, uphill.
If you don't have any idling issues or stalling issues then don't worry about it.
Anytime someone adjust one of those idle screws to compensate for a closed IAC there is an easy easy way to reset those idle screws.take off the air cleaner assembly at the throttle intake opening and just slide it over to the right. Now (without engine running) Look at the throttle plate valve and open the the throttle and close it. You should hear metal hit metal, if you don't then keep unscrewing idle crew until the throttle plate touches the cylinder opening. When the plate JUST TOUCHES the metal then that is where it goes! Then if it wont idle after starting its your IAC. When people turn those idle screws up they are bypassing a closed IAC is what theyre doing, but what is sad is that they think it is fixed. It wont hurt anything other than the engine might sie a few times at cold start up but a person can get by that way until they change that IAC
humm, im trouble shooting a 99 windstar 3.8L, that idles rough and stalls at stops when in gear,runs smooth when accelrating or staying at street/highway speeds, the IAC is clean and working, EGR working, new DPFE, only codes 171 & 174 bank 1 bank 2 lean, throttle plate in correct position,
ran good on July 1, several days later upper hose leaked and engine overheated
vehicle is Not mine, current 3rd owner recently acquired it, 183670.xx miles
Hi Paul - what if you have a third and fourth variable - an adjustable TPS and also a throttle body like the one you showed, plus it also has an air screw that you can turn clockwise or counterclockwise? I'm confused where to even start as the baseline here. (Ford probe, EEC-IV)
No engine light but idle fluctuates in Park only, As soon as I put it to reverse and then drive it is back to perfect idle at 750rpm. What is the problem, should I just ignore it?It runs fine in Drive and on all stops.
07 Ford tarsus stalls at lights or in park. I changed the iac and cleaned the throttle body and it didn’t help any. I bought a obd2 got a code for the idle air control circuit, cleared the code it hasn’t came back but still stalls I need some help
Hey Danner, i have a 2004 Ford Focus mk1 1.6 16v petrol. i have a problem with the idle, if the engine is warm, when I'm driving, and when I need to shift and press the clutch the idle drops to about 500 rpm than it raises to the normal idle speed and stabilize.And I've noticed that the car doesn't stay idle when letting it rolling in its 1st or 2nd gear. It stutters and keeps it with lots of work at normal idle speed. The car remains with a lot of trouble rolling, and does not fall out. But as soon as I move up a bit, the speed drops very low, and stutters but the car doesn't fall out. i already replaced the idle air control with a new one aftermarket Pierburg. i alread have reset the ecu 1 day disconnecting from battery and let is warm up at first start. also i have cleaned out the throttlebody and replaced the tps. The car idles very smooth when cold or warm and does not move any inch. once a week the car starts hard and stutters. The car drives very good and has lots of power. im lost and dont know what to do for this problem danner. Can you give me a suggestion pls ?
Great Video bro 😊
Thanks, very helpful.
Hi Paul at 1:57 you mentioned not knowing if it had a EGR flow problem because someone cleared the trouble codes, what effect would a EGR flow problem have on the IAC?
I only mentioned that as a guide to the technician who is selling the job, to make no promises about the check engine light, because someone just cleared the codes before it was looked at. So other problems could exist. That's all. It was a cover your ass statement.
An EGR flow (restriction) would have zero effect on idle speed and IAC function
That screw is even made in a way so you can't mess with it, since it has no head or anything. That should be indication enough that they don't want you to mess with it. xD Man scan tool is useful if you know what you're doing and know what you're looking at. Very cool stuff for sure.
I just wish I went to school for a technician. But hey, I can learn a bit this way too. :) I'll buy your book when I have bit more money, it's tough over here lately... Do you ship worldwide? Would love a hard copy if they are available.
Great and informative
i need to set my idle just 100 points higher to compensate for a weak oil pump. just 100 points will do. how do i do that on a 2002 ford ranger, 3.0 n??? i tried the screw, but the computer resets it
This is why I now have a 2011 Leaf EV, I'm going all electric vehicles in the future, and I recommend everyone do the same.
Sorry, but I'm so done with overly complicated smogged up ICE vehicles.
I'm fighting now with a IAC on my '92 40ft motorhome with a 460efi and I'm frustrated, confused, and pist off.
Likely got a bad new IAC complicating the fix. New one leaks vac slightly with power disconnected. SO DONE.....bad parts from suppliers etc etc SO DONE.
awesome vid very informative. thanks
ScannerDanner, My 2002 grand marquis stalls while driving. But starts right up. Is this due ti Idle control valve? Any help will be highly appreciated
Scanner Danner I have a 2001 and the code is P0351 means = # cylinder coil. now this is the second coil pact I'v replace in about 4 months. I did have the intake replaced because it was the recalled one and it finally cracked and leaked. everything ran great for months and then I replaced the # 4 cylinder and now it wants me to replace the #1. I have been having stall issues and this is prior to the # 4 cylinder replaced coil pack. I'm thinking it could be the crankshaft position sensor.. Whats your take? thanks. I watch you with Eric the car guy and I love the scanners you have. I just have the OBDII code finder. Nothing more. Have a good one.
I touched it. Works fine bra
lol
I need to be able to manually control my IAC to spin up my alternator to generate more power, but I don't have a stepper motor style IAC, it has this duty cycle version, does that mean I need to manual add more or less voltage to the IAC to get it to open more?
Great video. Can a bad PCV Valve cause a rich running condition ? Thank you
I would say no, unless the oil is fuel contaminated.
Thanks brother. I changed the oil after I had a coil misfire and replaced the coils and plugs. I am still getting rich post cat 02s on both sides. Did a injector balance test and they are all good dropping from 45 down to 22 on all 8 cylinders. Have 39 to 45psi fuel pressure at idle and have all four cats new, Walker, as the Ford cats were $2500 dollars for all four. Put all four Motorcraft 02s also. Has me stumped.
Rich O2s downstream of the cat is normal bro. The converter catches and stores oxygen.
OK. See, I learn more from you then I do the College I attend. Thanks again
thanks great job Keep it Simple! wsh
P0505 for 99 Durango(check engine also). Replaced I.a.c several times to no avail. Checked for vaccuum leaks, didn't sem to find any. Any ideas?! Been this way for over 1 year and emmissions is coming up real soon.
Hello and thank you for the video. Question, I did exactly as you said. At one time the idle plate was adjusted. I disconnected the IAC and the rpm jumped from 11k to about 14k. I unscrewed so the plate would close more but there was no change. According to the book my rpm should be at 700 idle. I added sandwich bag around the IAC to make sure there was no air being sucked in that area but still no change. I plugged the IAC and the RPMs dropped to about 11k again. I've cleaned the idle plate and body too. Can you think of what my next step should be? Thank you
Vacuum leak
I have a 1997 Ford Expedition XLT 4.6 that misfires on one cylinder due to low idle at 550 rpm. No misfire at 650. Can’t pass inspection. Can the rpm be raised a bit?
You'll set other codes by raising your curb idle screw to the point where the iac cannot reduce it anymore. But you could try
A fantastic info, signed up on your web page.
Thank you Scott! Look forward to the comments and questions. I'll do my best to answer them.
So what if I’m idling at 1100 and the idle screw is backing out but the throttle lever isn’t moving back
vacuum leak, IAC motor stuck open, IAC is being commanded open (input issue)
What is your IAC duty cycle command?
Still not sure how this can help. My 95 Ranger's idle speed gradually increased over a few days from 2000 to 3000, really screaming. Changed IAC valve, also found a crack in intake manifold, letting air in. Sealed crack, engine still screams. Ideas?
+Gary Crawford how does it idle with the IAC unplugged?
Hello everyone! I am not a professional mechanic at all just a man trying to help my wife's cousin who is a single mother. She has a 2002 Ford Taurus V6 engine. Car would run only if you would keep your foot on the throttle as soon as you would take it off it would stall. I replaced the ICV and it looks like the stalling issue is fixed but it seems to now be running just a little lean approx. 800-900 RPM kind of moves up and down a little! When I removed the old ICV the inside was filthy and she is not the best at maintaining the vehicle and not sure if the previous owner was either. Any help with the low RPM would really be appreciated. Have a wonderful week. -Paul
did you or anyone else mess with the throttle stop screw?
Hey there... please help.
My 2002 e250 van (cng) has a low idle this problem is new. It was fine then I just didn't drive the van for a long time the battery died when I jumped now it has a low idle. Ok. Im thinking that when the battery died it erased the position of the idle from the computer now the van is confused and doesn't know the correct idle position?!?!?!?!
I'm so confused on what to do!!!!!
Tap on the IAC motor, it's probably stuck closed. I have a video on this on a Ford
very good video, when we will teach failures data bus network
Looking at my scanner-live data, i only see RPM at drive (650) and RPM at neutral(750) , is RPM at drive the same for desire RPM IDLE? . I keep getting a buzing noise coming from the air tube that the iac valve is sucking air from.
roberto ortiz desired RPM is what the computer wants the car to run at. RPM should match Desired RPM. The buzzing sound you are describing could be a cracked bellows on the IAC valve itself. Older Fords had this issue. And it would also give you a higher than normal RPM at times. Pull the IAC off and look inside of it. Is there a plastic bellows inside of it? If so, gently look between the ridges of the bellows with a small pocket screwdriver, you will see the cracks.
I have a 99 grand marguis that idle rough and sometimes dies on cold starts,when it's warmed up it runs just fine,any suggestions
Sir, I had to adjust my low idle rpm , and i fixed it by adjusting the Throttle stop screw, and it also worked. But then heard there's another screw called Idle Air Adjustment Screw, which is there specially for this purpose of adjusting idle air flow? and that the Throttle stop screw should not be changed but instead the idle air adjustment screw should be adjusted?
I'm really having this confusion which one should i be adjusting and what are the difference between.these two?
IF you have an idle air adjustment screw, this should have been the one you adjusted. Most systems, all you need to do is to clean the throttle body to restore minimum idle speed.