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So, first time poster. I have an 1982 collectors edition, at least it was. Has been repainted and I’ve done a full restoration and just did black interior. Car has been totally rebuilt, drives great, runs great, HOWEVER, the IAC’s don’t do anything. I tried a couple cheap sets in it and have gotten some little more exspensive ones thru advanced auto and nothing. I’ve not been able to find any information about the operation or what each wire does as far as who’s hot at what time and how much voltage should be there etc. I think I’m getting 10v on some wires iirc. 10v seems odd to me. Any advice or incite would be greatly appreciated. I’ve done so much work on this car and for it to not be perfect is unsettling. I made the decision early on to just keep it stock, she’s just for driving and enjoying not hot rodding. Adding some photos for fun.
Unfortunately I can't help you out on the IAC issue, but you have done an amazing job on bringing this car back to a real beauty. You should be very proud of what you have done and I can understand your frustration. Having done this type of project I know the work and effort ( and $$) it takes to get it done. Hopefully someone else here knows about the crossfire engines and can answer your questions. Great job on the car
Well thank you very much Kanvasman. Lord knows it was a ton of work, never mind the 💵😬. Doing the work myself helped but they proud of parts that say corvette lol. Thanks again buddy.
I can only speak to the IAC on my 1986 TPI engine, but it appears that they do the same thing. Have you adjusted the pintle to spec with the IAC out of the unit? My understanding is that once it is adjusted to whatever the dimension is ( on the TPI it is 1 1/8" out with no voltage applied. Once that is correct then the voltage takes over. But if it is too far out of adjustment, the pintle will not travel far enough to adjust the air flow. And if it is too far out it will bottom out inside the housing. As for the voltage, maybe a schematic will at least tell you which wire should be hot. OR you might have an issue with the ECU. Maybe do a search or post the question on the C4 side since the 84 C4's had the same injection set up.
Jacob49
I was going to make a suggestion just based on my RamJet 350 but decided to look in the C4 section. Take a look at this post and also read the Before and After responses....... but I think this is what you are asking about. Of course you could go buy a Tech 1 to try controlling the IAC(not sure it wokrs on crossfire but it's mentoned in the thread... and not sure how much they are by now???).
Also...you can ask questions over in the C4 sections since the 84 used the crossfire. Anyway....hope this helps you.
Jacob49
anyway... if I had a 1982 and had to keep stock I'd go searching for a Vetronix Tech 1.... you'll see them on ebay here and there.... a couple of videos for your viewing enjoyment
What do you mean it "doesn't work". Is it stuck closed or open? (Guessing closed) How does it run great without the IAC's working? What are the symptoms you are dealing with?
Do you have a copy of the shop manual? If you are going to do any work on the CFI you NEED that!
Thank you all so very much for the replies. I’ll will be looking into all that was mentioned. Good idea looking at the c4’s. Brushmor, to answer your question. They don’t do anything so I have them in the closed position and the idle set via the idle screw 🤷🏻♂️ but it won’t start without cracking the throttle open and doesn’t idle well until it’s warm. Otherwise runs excellent. O and I have a c3 manual but the crossfire info is basically non existent.
You need to get the Factory GM manual or reprint of the original factory GM shop manual first, there's also a guy on here that has really nice wiring diagrams for free with an email so you need to look him up also . Welcome to the forum
One more thing is you can buy a GM Tech 1 or Tech2 on eBay fairly cheap and read all your sensor and codes on the tool from the ALDL connecter , they come in handy
Welcome to the Corvette Forum Jacob49! This is (Normally) the place to find answers to issues with the Corvettes.
Please don't give up yet as there are several Experts on the Crossfire engine systems that have yet to chime in. They are getting their C4's into the 12 second range with the Crossfire and that is pretty impressive. I have a 1988 C4 as well as my 1968 C3 and have learned the fuel injection system used on the L98's fairly well. I know nothing of getting 2 IAC's to work together to control the idle speed on one engine.
Do you have the Factory Service Manual set for the 1982 Corvette? The FSM's for the later cars came with two books, one was mechanical and the second was the electrical. The FSM's have the best and most accurate electrical trouble-shooting charts. It would be very hard to own any EFI equipped Corvette without a set of the FSM's handy. I have two sets, one in my shop and one inside the house. A clean set and a working set. GM must have produced something for the dealerships to use to fix the Crossfire engines.
Thank you all so very much for the replies. I’ll will be looking into all that was mentioned. Good idea looking at the c4’s. Brushmor, to answer your question. They don’t do anything so I have them in the closed position and the idle set via the idle screw 🤷🏻♂️ but it won’t start without cracking the throttle open and doesn’t idle well until it’s warm. Otherwise runs excellent. O and I have a c3 manual but the crossfire info is basically non existent.
As others have said, you need the factory manual (I have a used one that's beat up a bit I'll be selling soon so PM if you are interested).
In the meantime, here's the diagnostic procedure from the manual. You're already on the left side of the chart. Let's hope it's just a bad connection somewhere between the IAC and ECM and not the ECM itself .
Wow brushmor that’s some great info. I’ll definitely have to get the fsm. Should I get it for the ‘82 or ‘84? I’m concerned the Ecm may very well be the culprit
Wow brushmor that’s some great info. I’ll definitely have to get the fsm. Should I get it for the ‘82 or ‘84? I’m concerned the Ecm may very well be the culprit
There's way more than just the crossfire stuff so get the 82 shop manual. Rock Auto even has reprints electronic copies that are cheap.
1982 crossfire IAC problem
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