Ok my car is a 93 z28 with a six speed and I am having a problem with my car idling high and not slowing down. Up until today it had no problems but when I was stopped at a stoplight and I noticed that it was idling at about 2 grand. I revved it a little bit and it went back to normal so I didn't pay much attention to it but then at the next stop light it came back and also every time that I hit the clutch or it is in neutral it shoots up to like 2500 r's and doesn't go back down until I put it in gear. I am not sure what to do about this. Could it be the iac valve? If it is the iac valve should I just clean it? Any advice is much appreciated.

 

Could be a bunch of things.

Throttle could be dirty and sticky. It's easy to see if it is by pushing the throttle open by hand and seeing if it snaps back or not. If the RPMs stay up and the throttle came back then nope.

If throttle snaps back, could be a vacuum leak (such as intake gasket or such).

Could also be the IAC like you said. Google around for symptoms, causes and fixes. This site has plenty of info on it too.

 

ok I'll check that in the morning, thanks!