I have had this problem for like a month now and it is really peeving me off. When i start my 91 bird first thing in the morning, the idle will jump from about 300 to 3000. I can even out the idle with my foot, but as soon as a let off it will die. On the second start up it purrs like a kitten. Someone please help?

 

I think you have an (IAC) Idle Air Contol problem or the ECM part that controls it is about to go. Do you get a Check Engine light on?? I had a problem like that only my Camaro would die every time the A/C was on or if you slowed to a stop slowly, found out that the ECM wasn't contoling the IAC and what poped the ECM was that the IAC had gone to h*ll. You can get a used ECM for about 50 bucks (get a warrenty) at a junk yard, just match the service numbers/stickers on top. And buy yourself a new IAC at the parts store. I never got a Check Engine light but this fixed my problem.

 

No i never get a check engine light. My ecm is only about 3 months old. So i am guessing i can just change the IAC. Thank you for your help, i appreciate it.

 

The IAC valve tip and passageway could be very dirty with carbon, too. Click on search on the upper-right of this screen, and look for "IAC" - you should find my "how to clean" message. It takes 10 minutes and a spray bottle of "Throttle Body & Intake Cleaner for Fuel Injected Engines" (NOT Carb/choke cleaner).


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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