Hi, I have a 1996 sunfire Gt 2.4 DOHC automatic. Here's my problem. When i start my car cold, the idle goes to about 1500, then down to 1000 after a few seconds. then it sits there for awhile normally like its supposed to. after a few more seconds, it will start to jump up and down, between 500-1200, for approx. 15-30 secs. If you hit the gas it revs up fine, no bogs or misfiring. I know it could be a million things thats why i wanted to know if anyone else has had this problem and what the cause is?? and it only does this when below 1/4 temperature. thanks for any help

Sounds like the IAC motor. Do you have any codes?
Or maybe the AIT sensor. Neither are too bad price wise and there both easy enough to do.

Good luck




Semper Fi SAINT. May you rest in peace.

i have already changed the iac, not even a year ago, and the ait, was one of the next on the list, is there anything else this could be? and second, would it affect fuel mileage??
thanks

If the AIT sensor went yeah your fuel mileage will go too.




Semper Fi SAINT. May you rest in peace.

what kind of a difference would i be looking in mileage? and would it affect power or anything else? cause whe i get on the gas, it goes like it always has, just wondering

tried changing the throttle postion sensor yet???



"Freedom 'ought to have its limits"-George W. Bush may 31 1999 (who voted for this idiot?)

check the throttle body see if theres a lot of carbon build up, clean it while your there. also check the tps and the IAC vavle, if those are scerwed up it can cause that to happen. Clean teh IAC valve also.

cleaned the iac and throttle body twice already, going to try changing the iat sensor, could be that and its cheap, i hate guessing tho, and no i don't have any codes showing up, its weird...

check your coils, just because the car started does not mean there working right