I got an 86 iroc with tpi and i didn't know anything about these cars when i bought it, boy am i learning a lot quickly. Well my idle when i got it was nearly 2500 in park. I know there's no way thats right. so i turned it down but about the lowest i can get it is right around 2000 rpm. So thats still to high right, or is it? I dunno. It drops down to about 1500 when i put it in drive, but is this right? Let me know what u think maybe I'm not far off but i have no past with third gen camaro's so i'm not so sure.
Thanks, the new guy.

 

Still way to high. Try for like 800 in park and like 500ish in drive.

 

See teh label on the underside of the hood. IIRC it has the curb idle speed. If the IAC is still good and the throttle isnt hanging then youll need to re-adjust the min idle speed to where it was stock. Whatever the min idle speed is, it must be less then the curb idle speed for your car or the computer wont have any control over the idle.

 

You have a major vacuum leak. Fix that and then re-adjust your IAC that you totally messed up attempting to adjust your idle.

You can ONLY adjust the controlled idle rpm by re-programing your prom (chip).

 

Are you sure that your tachometer is correct? It's a common problem on 3rd gens to have the stock tach read too high (like mine). Is there any way you can hook up an aftermarket tach or get someone to hook up a scan tool to confirm if the stoch tach is right?

Also, does the idle ever drop down below 2000 RPM (say after driving for 5 minutes and letting it sit)?

 

Hey thanks guys but like i said i'm the new guy soo, i need some clarification with all this iirc or iac or whatever, how do i set it and all? I feel kinda dumb here but i don't even have a manual to go off of right now. Na i don't have ne way of testing to make sure the tach isn't messed up right now, but i'm gonna see what i can do to borrow another tach. Thanks alot, keep the help coming.

 

No need to adjsut the IAC. All resets are handled automatically by the ecm upon every shut down.

 

The ecm can only automatically adjust so far. If the IAC was adjusted totally closed in an attempt to lower the idle due to say a vacuum leak then the ecm cannot bring it back up to where it needs to be to properly maintain an idle. PLUS, everytime you adjust the IAC you have to at least check (and adjust) the TPS.

The procudure for adjusting the IAC and TPS can be found in the tech section. Here's a link.
https://www.thirdgen.org/newdesign/tech/tpimod2.shtml

 

Is there a solution for this? I have found at least 4 different threads dealing with high idle, but no solutions have been posted. It's my turn to deal with this, and it would be nice to find that someone has figured it out.

1985 Firebird, 2.8L V-6, 5 Speed.

Idling at 2500 rpm with the IAC simply not moving. Can the Mass Airflow Sensor (MAF) cause this??