hello, I've been digging though theads to find a solution to my problem here but have been coming up short. the car is a 91 trans am 350 tpi car. just put a new ecm in it and had the fuel rails cleaned and now it's idleing out of my control, on cold start it revs up to 3k and slowly decreases down to 1500. and when it warms up it increases up to 2500 and seems like it has the means to keep on going. any help would be appreciated, thank you

 

Sounds like the Idle Air Control valve is either bad, dirty or out of adjustment. Here is how to clean and adjust it.


http://www.iroczone.com/2009/10/clea...rol-iac-valve/

 

I'll give that a try after work tomorrow, I'll keep you informed, thanks!

 

Check for air leaks as well. Those can cause high idle on speed density cars as well.