ok so i have the ECM852 from moatis.com and im datalogging my motor. i found that my iac counts were way off so i fixed that and now the motor seems much better then befor, got the counts to around 8-18 at idle, but it seems when i drive it around not all the time but somtimes the idle will seem to stick and be a lil high. not sure if my iac is stickin "brand new iac motor" or if it has to do with all my mods makin the motor/prom out of tune, what do i need to look at or do to get this to stop?? also whats next for tunning my prom, what should i be lookin for when dataloggin and what can i do to get her runnin even better? thanks

 

When the idle sticks high, are the IAC counts also staying high?

The computer has no real idea of where the IAC is, it just tells the IAC to change from where it thinks the IAC is at. For example if the IAC counts stay high, the IAC itself is not "stuck," it's the algorithm in the ECU that is calculating that the position should not change, thus the ECU is making it stuck (but ECU is not bad just some calibration parameter is).
There are several things that can cause the algorithm to keep the IAC high. Is your throttle closing all the way during the high idle?? Is the vehicle rolling a little? Is the problem in Park, or in Gear? AC on or off? Try to find a repeatable procedure to recreate the problem, and it'll be much easier to diagnose the cause.

 

well it seems to do it when ever it want the motor and ecm is in a 92 fullsize chevy truck but i dont know how that would have anythin to do with it!! need more help in this anyone???