ok I need some help here!!! I have a 89 Iroc Z 350 TPI Well I just got the engine rebuild and when I start it the idle is way up to 1500 and it stays no matter what. Even when its warmed up it dont make any difference. I put it in drive and its at 1000 or 1100. I have changed the mass air flow sensor and relay. I have tried to adjust the idle by the idle screw, but for some reason the throttle thing wont even touch the screw. I try to push it back towards the screw but no nothing. Well let me know what you think or how I should adjust it. Thanks Joey

 

It sounds to me like the first thing you need to do is adjust the throttle position sensor to specification.

 

I am a veteran of the bad idle problem. I checked EVERYTHING in my car. If the screw is all the way back and idle is still that high I would say you have a prett severy vacuum leak. A cheap way to check is put a hose to your ear and the other end travels all aroudn the intake area and where you hear sort of whistling the vacuum leak is.

-Max