Hey guys. I wanted to get some more opinions on this. I have a 95 Z28 Camaro with an automatic tranny. The car is idleing too high. I know there can be a number of problems that would cause this such as unmetered air getting past the MAF, vacuum leaks, and others. I have checked for vacuum leaks, and I have taken the air intake pipe off and temporarily fixed some small cracks it has in it at the throttle body connection and that seems to have mostly fixed the problem. But it is still idleing too high and the longer it runs the worse it gets. I don't ever let it run for more than a few minutes because it get's kinda rediculous but I just cranked it up a few minutes ago and it was idleing normally at first. Then after about a minute it bumped up to about 1100rpm. I goosed the throttle a bit and it came back down to 1200 and stayed there What do ya'll recommend? If you don't mind, just tell me what you personally would do step by step so I can have a good idea of what exactly to check.

 

Make sure the throttle valve and all the cables attached to it are not sticking. The throttle valve should be closed down all the way at idle speed.Check for air leaks from the throttle valveto the intake manifold. The MAF does not control idle speed, it just measures the air going to the engine. Idle speed air is provided by the idle air control valve (IAC)under the control of the PCM. Also look at the throttle position sensor, although it should not cause your problem.

 

Thanks Z28pete, where is the idle control valve?

 

Also, I read on shbox that there is a problem with the intake manifold developing a leak at the back of the engine where one of the emissions pipes runs along the back of it causing it to heat up and ruin that part of the gasket. Could that cause this problem or would that just cause an oil leak?

 

The leak at the rear of the intake manifold is just a common plain old oil leak and does not affect how the engine runs. However, there could be a bad gasket between the intake manifold and the cylinder head.

IAC Valve location http://shbox.com/1/iac3.jpg

Other things to check:
PCV valve
EGR valve should be closed when idling
AIR pump should not be running when engine is warm

 

Cool, thanks very much again z28pete!