84 4cyl. bad idle

[sixpack_cuda]

When I start up my Fiero, it revs up to 3000 rpms and stays there for a while. But after it's warmed up, it starts to slowly drop down and eventually goes to around 1000, but even then it still isn't steady.

Could anyone give me some advice as to what they think might be the most likely reason?

Thanks

[GiddyUp85GT]

Is your check engine light on? If so you'll have to check it for codes, there is another thread here that shows you how to do that. It could be a vaccum leak or you could have a problem with your AIC Air Idle Control Valve. I replaced by AIC and she was fine. I had the same symptoms. Car is supposed to stay at idle at 900 and of course not fluctuate. Do you have a haynes manual by chance??

[sixpack_cuda]

oops, forgot to mention that, no the check engine light doesn't come on at all. Also, it chokes whenever I give it gas, and then it revs.

no I don't have a haynes, i've got a chiltons manual though.

I've been checking for vacuum leaks, and can't seem to find any. And being that my check engine light doesn't come on, does that mean that my AIC is probably okay? or should i check it anyway?

[GiddyUp85GT]

Originally Posted by sixpack_cuda

oops, forgot to mention that, no the check engine light doesn't come on at all. Also, it chokes whenever I give it gas, and then it revs.

no I don't have a haynes, i've got a chiltons manual though.

I've been checking for vacuum leaks, and can't seem to find any. And being that my check engine light doesn't come on, does that mean that my AIC is probably okay? or should i check it anyway?

I'm assuming the bulb works in the first place? Sometimes people like to pull them out.
I surprised its not throwing a code. With the AIC sometimes you don't need to actually replace it just clean it up with some throttle body cleaner. Hope that helps. I wish i had a pic of it but its on the left side of the engine closer to the firewall. A large socket will loosin it up.

[GiddyUp85GT]

ah i just noticed you have a 4 banger, just check your chiltons to locate it. Also check out this site www.fiero.nl lots of knowledgeable people and a great fiero site.

[sixpack_cuda]

Nope, the bulb still works I did run a check on the system, and I got code 12 continuously, so I guess everything is ok according to the ECM.

I will, however, take out the AIC and clean it up a bit. Are there any other sensors or similar things I could check? Thanks for your help