Hey everyone need some input here please, just recently noticed my idle was racing away like crazy from 1150 rpm to sometimes 1800 rpm when I come to a stop. I have GSC S2 cams so I would usually be ard 1100 to 1200 rpm. I started to adjust the idle screw around by the throttle body but it would idle perfect then will go down to 950 rpm and be back and forth. My car doesn't misfire, burn oil or smoke so I was thinking maybe its my idle speed control motor ? Would really appreciate if anyone here had this problem before and what was the fix thanks guys.

 

Oh also I am currently on meth, so was thinking if the meth probably damaged the isc from time to time? I am running 80/20 mixture.

 

The EGR can damage the IAC, the exhaust can gum up the throttle body and idle air passages. Firs thing I would do is pull the TB off and clean it out. Second thing is an EGR delete.

 

I will pull the throttle body and give it a clean, I had gotten a used IAC from Ebay for cheap will swap as well when I take the throttle body off see if that helps thanks John.