Thanks so much for posting this!! I have an 82 Vette in the shop right now and its been a few weeks since disassembly so i needed a refresher on which parts go to which throttle body. This was super helpful!
What I have done before to block off the EGR Valve, made a blank plate of course, but cut shaved the botton off of the EGT valve, making the thickness of the EGR bottom plate thinner, then mounted the blank plate and EGR on top with factory bolts, made it look like a working EGR to pass visual if I ever had to smog the vehicle.
chickenjo23 thank you! Yes, I still need to hook up a fuel pressure gauge in between the two throttle bodies and get and actual reading while engine is running. Since this video I also pulled a check engine light code that stood for TPS misadjusted/needs replaced. The Vette is still waiting for its new clutch and can’t wait to get her tuned better. Thanks so much for the answers and feedback !
My 1992 GMC 350 truck, was designed specifically to get way better mileage than 1960s 1970s trucks, producing 18 to 21 MPH on vacations driving on freeways. Any deviation drops the mileage way down to 12 MPH. I installed an Edelbrock intake manifold which has a slightly higher deck rebuilt the factory Rochester throttle body produced horrible mileage and less horsepower and torque. Cleaned the original intake manifold put that back in then used two throttle body spacers, way better MPH and horsepower and torque. Also, people will use Fel Pro gaskets on the GM intake manifolds, I wrote to Fel Pro said what Truck I have, and they said DO NOT USE OUR GASKETS, we do not make gaskets for those TBI vehicles, the rear port on ours is made wrong, then said DO NOT use silicon on the OEM gaskets either, after 7 Auto shops changed my Intake Manifold gaskets and failed, I finally have a perfect running truck after years of suffering and wasted fuel. Sharing to help others.
The egr does leak and the solenoid for it also leaks. This is the main issue that caused the crossfire design to fail. Designed for fuel mileage and emissions. Low power but can run good with good low end torque. 25 mpg possible on the highway. To check egr / solenoid , plug vacuum hose from pass. TB to solenoid. Will start and idle smooth again after a couple of restarts. Do not pay $250 for new solenoid. Charcoal canister has one also.
In the 1984 l83 corvette, what are the specific places in the intake manifold where there are vacuum leaks????? Is it advisable to apply silicone under the TBI packaging??? And it is advisable to apply silicone on the intake manifold cover gasket??? What packaging is recommended????
@@angelfox1864 hi there, as you may know there is a lower intake manifold that is bolted to the heads, then a cover plate that is bolted to it, then both TBI’s are bolted to it. New gaskets for each layer and properly torturing the bolts should provide adequate sealing against vacuum leaks. If you have vacuum leaks I would follow steps to isolate the location and then determine if it’s possible loose bolts, maybe a crack in the intake itself. Let me know what you find and I can try and help. It’s possible to have leaks in the throttle bodies themselves which can be remedied by the rebuild kit you see in video and again if any metal parts are cracked you would need to address those. You shouldn’t need any silicone at all when sealing everything up.
Good video but you really should have marked everything and disassemble the fuel lines and linkage while it was still on the car. Also keep in mind that the actual injectors are different on the crossfire. I’m assuming there was a fuel distribution problem but the do carry different part numbers.
Michael Trevisan thanks man, so is fuel coming out only while engine running or even while it’s off is it dribbling out? Accumulator rubber gaskets could have a split somewhere or possibly you have a fuel leak at the top cover where the paper gasket may have split etc. Highly recommend getting a rebuild kit and making sure old gaskets, o-rings, anything rubber is replaced. Let me know more if you’re still having trouble!
Help !! Lol Do you have a link for the gasket kit you ordered ? The one you got matches perfect EXCEPT for the rear diaphragm gasket. In your video at 10 minutes 21 seconds, you can see that yours has a smaller separate swivel Piece on the bottom. The one I got didn’t have that. It looked like the other one but the round portion was 3 times thicker than the other one. And it didn’t seat right onto the housing. And no matter where I look for the 1984 crossfire injection kits, they all show the one I got and NOT the one with the swivel. I’d like to get the kit you have. I’d really appreciate any help you can give. I’ll check back here for a reply. Not sure how reply’s work on here. Mines a 1984 too
Where did you get your parts kit? I’m not sure which one is which but the diaphragms are a pressure regulator and pressure accumulator; I did a quick Google search for 1984 corvette crossfire throttle body rebuild kit and several options came up with the picture showing the correct looking part. I can’t recall where this particular rebuild kit was purchased, possible through Amazon or Ebay? I’ll keep looking around, some local parts stores might have some more info and where to get them, Autozone had it listed as available on their website but not sure if that was correct or not.
Awesome. Thank you. Ya the kit I bought was from Amazon. It said that it “fits” and most of it did. But I haven’t had any luck at my local parts stores (Napa, Autozone, O Riley’s. So far most things I’ve asked them For they say they can’t get it. Spent three weeks trying to get new fuel Feed lines and had no luck. Ended up fixing the old ones and plan to get braided lines made once I get this all back together and running. I’m a first time car guy and started with something small and before I knew it I had the whole fuel System out haha. Luckily took many videos so I know how it goes back together lol. But I ordered the Haynes repair book for the 1984-1992 vett. It showed up and doesn’t have any images of the crossfire engine. So as a non cad guy, it has me turned around. But this was the goal,was to rebuild it and learn as I go. My son will have this in 7 yrs when he can drive lol. Hopefully I’ll have it back together by then. I think what over learned is that since I’m not a mechanic and don’t know all that I should, for parts I need to go directly to Corvette specialty stores. Because the local parts stores here either don’t know this crossfire engine OR they don’t want to “teach me” and so they say they don’t have anything. I’m guessing if I knew more about cars that some Of this stuff I could find by using similar parts from other Chevy cars. Like I was surprised none of them pointed me to braided feed lines. At least as a last resort. Anyway, I’ll keep looking. Very much appreciate the reply !!! It was my first time commenting on any video and wasn’t sure id hear back or where to look if you did. I just came back to the comments to find it, but maybe it also sends me a notification I’ll post an update when I get it going !! And thanks again !!
Hey Ricky, I got it locally at a parts store; if you type in: 82-84 Crossfire Throttle Body Rebuild Kit, you should find some good options that carry the pressure regulator and accumulator diaphragms as well as all the gaskets etc you need.
I know the video is old but, I just bought an 84 Corvette in May and it smells like it’s running really rich. And idea what could be causing it? Not very familiar with crossfires and don’t want to start tearing into it. Any suggestions? Also I noticed, when the fan kicks on at 223F, it starts to smoke a bit and when it cools down, it stops. Driving me mad.
Hi Lance, first thing is your air filter clogged at all? I would change the oil, air filter, and fuel filter (if you know they haven’t been done lately) and then run all the old fuel out of it and put fresh fuel (get the old fuel out before you put new fuel filter on) If it’s running rich and it’s not a clogged air filter it could be some sort of sensor issue causing the injectors to stay open longer than they should or the injectors could also be dirty/carbon clogged and they aren’t closing all the way (this wouldn’t be likely but could cause some issues, like hard starts/extended cranks due to fuel dripping into intake. Check your PCV valve to make sure it isn’t clogged. If your issues haven’t cleared up after the basic maintenance stuff I would purchase a repair manual or find something online that can tell you how to test the fuel injection system for proper operation, like checking for proper voltage etc. Check the ignition timing to make sure it’s correct. It could be a bad coolant sensor or O2 sensor but you should see your check engine light on. Is your check engine light on? What you’re looking for is why is the engine too little air or too much fuel. If any shops in your area have an emissions analyzer you could have them test and see what your Hydrocarbon and Carbon Monoxide levels are, which would point you in the right direction. Off the top of my head I can’t think of anything else but if I do I’ll comment again. On mine years ago I had to replace the ECM due to it not starting without spraying carb clean dow throttle bodies and once it ‘jumpstarted’ it would stay running, pretty weird. Let me know if you have any specific questions, sorry I couldn’t be more helpful!
As far as your cooling fan, it’s probably the motor going bad, with engine off spin fan and try to wobble it, if there’s any play or when you spin it feels rough the motor is heading south. Check wiring going to motor to see if there is any reason for higher resistance, melted parts etc. If you have to replace fan motor, replace fan relay as well. Good luck and let me know how it goes!
I forgot to say about rich condition, check fuel pressure to make sure it isn’t too high. (You need to do this in between driver and passenger injector with engine running, you’ll have to make a way to spice into metal fuel line to hook up tester)
@@LastFrontierGarage thanks for your response. I have changed the throttle control sensor, those two sensors in the throttle body, the idiot I bought it from, cut the fuel line and I have a braided fuel line on it now. Air filter is new. Only thing I haven’t changed is the fuel filter. It starts easy. It runs rough until it gets to operating temp and then smooths out. Now for example if I sit in a drive through and the temp gets to 223 where the fan kicks on, it starts to smoke. Not sure what that’s all about.
@@lancebrantlinger-tommy3558 there might be an issue with temp sensor related to how much the computer adds fuel at start up, for example if the computer is getting the wrong temp sensor as if it were colder outside than it really is it will add fuel and run rich etc. I don’t know off the top of my head how to test everything besides getting voltage readings with engine running and making sure they match up to specifications. I addressed the fan motor smoking on this thread, let me know if you don’t see it.
This makes no sense; I buy the rebuild kits for throttle bodies like this. The regulator springs in each of several regulator rebuild kits are all different lengths ordered for the same 1992 GMC 350 truck. I understand if the tension is the same should not matter, but still I would think every kit should have the same length regulator springs in these kits.
I believe that is the fuel outlet fitting, you should be able to find a brass replacement at a plumbing store maybe? If it’s broken on the throttle body side you might need a new throttle body base
@@knightriderhelpjeanluc I’m not exactly sure which part you need but I think you need the fitting that adapts the fuel line to the throttle body? What part are you looking for?
Your info is so wrong, front tbi uses a compensator the rear is the regulator, the little part your aimlessly spinning is the adjuster for fuel pressure, nothing personal and I appreciate your atemp here but your not well informed on this stuff
Hey man thanks for the feedback, I think I made some mistakes in the segment you may have watched, there’s also another video but for sure this isn’t the best how to video for these things. I had the compensator and regulator flipped flopped when describing them and yes did figure out the fuel pressure adjuster although still haven’t figured out what the base setting is. Do you know? Anyhow, best of luck to you and have a great weekend!
Thanks so much for posting this!! I have an 82 Vette in the shop right now and its been a few weeks since disassembly so i needed a refresher on which parts go to which throttle body. This was super helpful!
So glad it could help, thanks for watching!
@@LastFrontierGarage of course, Ive liked and subscribed as well!! Have a great day!
@@WTmac1993 Thank you!!
What I have done before to block off the EGR Valve, made a blank plate of course, but cut shaved the botton off of the EGT valve, making the thickness of the EGR bottom plate thinner, then mounted the blank plate and EGR on top with factory bolts, made it look like a working EGR to pass visual if I ever had to smog the vehicle.
Nice!
That first unit you worked on is your fuel pressure regulator. By turning it you were adjusting the pressure of the fuel.
chickenjo23 thank you! Yes, I still need to hook up a fuel pressure gauge in between the two throttle bodies and get and actual reading while engine is running. Since this video I also pulled a check engine light code that stood for TPS misadjusted/needs replaced. The Vette is still waiting for its new clutch and can’t wait to get her tuned better. Thanks so much for the answers and feedback !
@@LastFrontierGarage I built my own fuel line between the tbis with a pressure gauge on it so I know what it's running at all times.
chickenjo23 that’s awesome, for sure will be doing that!
@@chickenjo23 Do you have any pictures and parts list for the line you made? I have an 83 Camaro Crossfire I would like to do the same thing to it.
Front unit is your compensator. Rear unit is your regulator. Once you rebuild them adjust your pressure to 13lbs. Your car will run so much better.
chickenjo23 wow, thanks for the spec I appreciate it !!
Where do adjust it? I have the same setup with the LU5
@@j.g.1351 From that screw he was turning that he said I don't know what this is. at 6:30 in you must remove plug n the bottom of the metal housing.
My 1992 GMC 350 truck, was designed specifically to get way better mileage than 1960s 1970s trucks, producing 18 to 21 MPH on vacations driving on freeways. Any deviation drops the mileage way down to 12 MPH. I installed an Edelbrock intake manifold which has a slightly higher deck rebuilt the factory Rochester throttle body produced horrible mileage and less horsepower and torque. Cleaned the original intake manifold put that back in then used two throttle body spacers, way better MPH and horsepower and torque. Also, people will use Fel Pro gaskets on the GM intake manifolds, I wrote to Fel Pro said what Truck I have, and they said DO NOT USE OUR GASKETS, we do not make gaskets for those TBI vehicles, the rear port on ours is made wrong, then said DO NOT use silicon on the OEM gaskets either, after 7 Auto shops changed my Intake Manifold gaskets and failed, I finally have a perfect running truck after years of suffering and wasted fuel. Sharing to help others.
Wow, what an ordeal glad you got it sorted out. Thank you for sharing!
The egr does leak and the solenoid for it also leaks.
This is the main issue that caused the crossfire design to fail.
Designed for fuel mileage and emissions. Low power but can run good with good low end torque. 25 mpg possible on the highway.
To check egr / solenoid , plug vacuum hose from pass. TB to solenoid.
Will start and idle smooth again after a couple of restarts.
Do not pay $250 for new solenoid. Charcoal canister has one also.
Twin Turbo thank you for the info !!
In the 1984 l83 corvette, what are the specific places in the intake manifold where there are vacuum leaks????? Is it advisable to apply silicone under the TBI packaging??? And it is advisable to apply silicone on the intake manifold cover gasket??? What packaging is recommended????
@@angelfox1864 hi there, as you may know there is a lower intake manifold that is bolted to the heads, then a cover plate that is bolted to it, then both TBI’s are bolted to it. New gaskets for each layer and properly torturing the bolts should provide adequate sealing against vacuum leaks. If you have vacuum leaks I would follow steps to isolate the location and then determine if it’s possible loose bolts, maybe a crack in the intake itself. Let me know what you find and I can try and help.
It’s possible to have leaks in the throttle bodies themselves which can be remedied by the rebuild kit you see in video and again if any metal parts are cracked you would need to address those.
You shouldn’t need any silicone at all when sealing everything up.
Good video but you really should have marked everything and disassemble the fuel lines and linkage while it was still on the car. Also keep in mind that the actual injectors are different on the crossfire. I’m assuming there was a fuel distribution problem but the do carry different part numbers.
Thank you for the tips!
Great video, I have fuel coming out of my accumulator spring throttle body which causes it to flood, I replaced the diaphragm any ideas?
Michael Trevisan thanks man, so is fuel coming out only while engine running or even while it’s off is it dribbling out? Accumulator rubber gaskets could have a split somewhere or possibly you have a fuel leak at the top cover where the paper gasket may have split etc. Highly recommend getting a rebuild kit and making sure old gaskets, o-rings, anything rubber is replaced. Let me know more if you’re still having trouble!
Help !! Lol Do you have a link for the gasket kit you ordered ? The one you got matches perfect EXCEPT for the rear diaphragm gasket. In your video at 10 minutes 21 seconds, you can see that yours has a smaller separate swivel Piece on the bottom. The one I got didn’t have that. It looked like the other one but the round portion was 3 times thicker than the other one. And it didn’t seat right onto the housing. And no matter where I look for the 1984 crossfire injection kits, they all show the one I got and NOT the one with the swivel. I’d like to get the kit you have. I’d really appreciate any help you can give. I’ll check back here for a reply. Not sure how reply’s work on here. Mines a 1984 too
Where did you get your parts kit? I’m not sure which one is which but the diaphragms are a pressure regulator and pressure accumulator; I did a quick Google search for 1984 corvette crossfire throttle body rebuild kit and several options came up with the picture showing the correct looking part.
I can’t recall where this particular rebuild kit was purchased, possible through Amazon or Ebay?
I’ll keep looking around, some local parts stores might have some more info and where to get them, Autozone had it listed as available on their website but not sure if that was correct or not.
You can try searching some 84 Corvette or Crossfire Injection forums and you might dig up some info there as well.
im not getting fuel to the injectors but I hear the injectors pulse, could the pressure regulators be bad?
Orozconleche what is your fuel pressure before the first (front) TBI?
Check the fuel pump
Fuel pump is bad.
Awesome. Thank you.
Ya the kit I bought was from Amazon. It said that it “fits” and most of it did. But I haven’t had any luck at my local parts stores (Napa, Autozone, O Riley’s. So far most things I’ve asked them
For they say they can’t get it. Spent three weeks trying to get new fuel Feed lines and had no luck. Ended up fixing the old ones and plan to get braided lines made once I get this all back together and running. I’m a first time car guy and started with something small and before I knew it I had the whole fuel
System out haha. Luckily took many videos so I know how it goes back together lol. But I ordered the Haynes repair book for the 1984-1992 vett. It showed up and doesn’t have any images of the crossfire engine. So as a non cad guy, it has me turned around. But this was the goal,was to rebuild it and learn as I go. My son will have this in 7 yrs when he can drive lol. Hopefully I’ll have it back together by then.
I think what over learned is that since I’m not a mechanic and don’t know all that I should, for parts I need to go directly to Corvette specialty stores. Because the local parts stores here either don’t know this crossfire engine OR they don’t want to “teach me” and so they say they don’t have anything. I’m guessing if I knew more about cars that some Of this stuff I could find by using similar parts from other Chevy cars. Like I was surprised none of them pointed me to braided feed lines. At least as a last resort.
Anyway, I’ll keep looking. Very much appreciate the reply !!! It was my first time commenting on any video and wasn’t sure id hear back or where to look if you did. I just came back to the comments to find it, but maybe it also sends me a notification
I’ll post an update when I get it going !! And thanks again !!
Where can I find that gasket kit you used?
Hey Ricky, I got it locally at a parts store; if you type in: 82-84 Crossfire Throttle Body Rebuild Kit, you should find some good options that carry the pressure regulator and accumulator diaphragms as well as all the gaskets etc you need.
I know the video is old but, I just bought an 84 Corvette in May and it smells like it’s running really rich. And idea what could be causing it? Not very familiar with crossfires and don’t want to start tearing into it. Any suggestions? Also I noticed, when the fan kicks on at 223F, it starts to smoke a bit and when it cools down, it stops. Driving me mad.
Hi Lance, first thing is your air filter clogged at all? I would change the oil, air filter, and fuel filter (if you know they haven’t been done lately) and then run all the old fuel out of it and put fresh fuel (get the old fuel out before you put new fuel filter on) If it’s running rich and it’s not a clogged air filter it could be some sort of sensor issue causing the injectors to stay open longer than they should or the injectors could also be dirty/carbon clogged and they aren’t closing all the way (this wouldn’t be likely but could cause some issues, like hard starts/extended cranks due to fuel dripping into intake. Check your PCV valve to make sure it isn’t clogged.
If your issues haven’t cleared up after the basic maintenance stuff I would purchase a repair manual or find something online that can tell you how to test the fuel injection system for proper operation, like checking for proper voltage etc.
Check the ignition timing to make sure it’s correct.
It could be a bad coolant sensor or O2 sensor but you should see your check engine light on. Is your check engine light on?
What you’re looking for is why is the engine too little air or too much fuel.
If any shops in your area have an emissions analyzer you could have them test and see what your Hydrocarbon and Carbon Monoxide levels are, which would point you in the right direction.
Off the top of my head I can’t think of anything else but if I do I’ll comment again.
On mine years ago I had to replace the ECM due to it not starting without spraying carb clean dow throttle bodies and once it ‘jumpstarted’ it would stay running, pretty weird.
Let me know if you have any specific questions, sorry I couldn’t be more helpful!
As far as your cooling fan, it’s probably the motor going bad, with engine off spin fan and try to wobble it, if there’s any play or when you spin it feels rough the motor is heading south. Check wiring going to motor to see if there is any reason for higher resistance, melted parts etc.
If you have to replace fan motor, replace fan relay as well.
Good luck and let me know how it goes!
I forgot to say about rich condition, check fuel pressure to make sure it isn’t too high. (You need to do this in between driver and passenger injector with engine running, you’ll have to make a way to spice into metal fuel line to hook up tester)
@@LastFrontierGarage thanks for your response. I have changed the throttle control sensor, those two sensors in the throttle body, the idiot I bought it from, cut the fuel line and I have a braided fuel line on it now. Air filter is new. Only thing I haven’t changed is the fuel filter. It starts easy. It runs rough until it gets to operating temp and then smooths out. Now for example if I sit in a drive through and the temp gets to 223 where the fan kicks on, it starts to smoke. Not sure what that’s all about.
@@lancebrantlinger-tommy3558 there might be an issue with temp sensor related to how much the computer adds fuel at start up, for example if the computer is getting the wrong temp sensor as if it were colder outside than it really is it will add fuel and run rich etc. I don’t know off the top of my head how to test everything besides getting voltage readings with engine running and making sure they match up to specifications. I addressed the fan motor smoking on this thread, let me know if you don’t see it.
This makes no sense; I buy the rebuild kits for throttle bodies like this. The regulator springs in each of several regulator rebuild kits are all different lengths ordered for the same 1992 GMC 350 truck. I understand if the tension is the same should not matter, but still I would think every kit should have the same length regulator springs in these kits.
Link to parts plz
I’m not sure if this was the exact same kit but if you search online you should find several versions of this kit. a.co/d/a5oVqGA
please what is the name of the parts at 29:27 min ? have broken mine inside need one
I believe that is the fuel outlet fitting, you should be able to find a brass replacement at a plumbing store maybe? If it’s broken on the throttle body side you might need a new throttle body base
@@LastFrontierGarage dont find any store to buying one outlet...maybe with chance you have a link? thanks friend
@@knightriderhelpjeanluc where are you located ?
@@LastFrontierGarage france friend
@@knightriderhelpjeanluc I’m not exactly sure which part you need but I think you need the fitting that adapts the fuel line to the throttle body? What part are you looking for?
Your info is so wrong, front tbi uses a compensator the rear is the regulator, the little part your aimlessly spinning is the adjuster for fuel pressure, nothing personal and I appreciate your atemp here but your not well informed on this stuff
Hey man thanks for the feedback, I think I made some mistakes in the segment you may have watched, there’s also another video but for sure this isn’t the best how to video for these things. I had the compensator and regulator flipped flopped when describing them and yes did figure out the fuel pressure adjuster although still haven’t figured out what the base setting is. Do you know? Anyhow, best of luck to you and have a great weekend!
too much blaa blaa blaaaaa
Can’t disagree with that lol