I just purchased a base 94 Vette with 12400 miles. It starts on fast idle and won't kick it off. I can't believe that the idle control valve would be bad with that few of miles on the car. What could it be?

 

Welcome to the forums. It could very well be the IAC valve having issues. sticking or bad maybe check the EGR valve also make sure it's working right maybe a vacuum leak somewhere maybe.

 

I already purchased a new valve, but I didn't think about the EGR. I also thought about a vacum leak but I sure hope that isn't it。 Thanks for your help。

 

I was also thinking that maybe it's not slow idleing is because the thermostat is stuck open or a temperature sensor is bad. It thinks it's cold, there are 2 sensors for reading engine temperature one is for the dash gauge and the other one is for the ECM, It could be possible the engine temp sensor for the ECM is bad and not tripping a Code and staying in open loop cold mode. Maybe?. Is the engine warming up fairly quickly? GM likes the engine to warm up quickly to inter closed loop mode, within 5
minutes and at about 160 degrees. That was a thought I had.

 

I just went out and started her up and the temp went just over 185. I still couldn't get it to slow the idle down. It idles at 2000 and I'm afraid to try to drive it to a shop. I just can't believe that with just under 12400 miles on this 94 that the IAC could be bad. Is there anyway that I can turn the idle down so I can get it to a shop?

 

It's something you can try, it sounds like the IAC is in the open position (screwed in toward the IAC motor). Unscrew the IAC from the manifold, manually turn the plunger out most of the way, reinstall the IAC valve, you won't have a fast idle, it might work, you will be guessing idle speed. I would try to install a new valve first.

 

I will replace the IAC tomorrow morning and see if that helps. Thanks again for your help.

 

I will replace the IAC tomorrow morning and see if that helps. Thanks again for your help.

 

molesen: Welcome to the forum. Hope that fixes it. Does the throttle work normally?

 

Yes it does. Thanks