My car has been haveing this messed up idle for a few weeks, the RPMS will go up and down as far as between 500-900RPMS. Yesterday it actually cut off once it dropped so low.

This morning, it wouldnt crank, the engien was turning finially it cranked but was spuddering real bad like it was barley running. Then afetr a few seconds it started to idle normal, not normal becaus the RPMs is still bounceing around. Im going to take a chance now and drive her to work. Think it has something to to with the IAC valve or mabey a vacume leak. A few months ago, the IAP valve gave off a reading of 0.

 

You can pull the vacuum line off a valve just forward of the pcm and hook a vacuum pump with a gauge to it and check it there. Usually IAC's just quit and don't idle at all from my experiences. Have you made any recent changes? Could also be an 02.

 

this weekend ill take it to autozone and see if it throws any codes i do t know is already there. I did just do a th400 swap. The sympton is real similiar to when an air vacume hose was leaky, but it idles real high.


I also noticed, when i disconnect my AIC now, it used to idle high, now the idle dosent change!?!?! I just have alot pointing towards that IAC.