Just wondering why my '85 Camaro Z28 idles high only are start up and never after that. As soon as its started it'll jump to 1500 RPMs, hang there for about 5 seconds and then slowly climb to normal idle RPMs? Any answers?

 

the IAC is either open or closed whichever is the at rest setting then it slowly works its way back to the ECU controled idle.

 

Is there a way to eliminate the high idle at start up? What do I need to do?

 

You can reprogram the target idle adder versus coolant temperature parameters, the added IAC steps for cold start, and the start timer. The factory programming runs the engine at higher RPM during starts, then steps it down to the "normal" warm idle RPM. That's completely normal.

 

How do I reprogram the target idle, IAC cold start and start timer? Is that something I can do myself?

Would replacing the IAC help out at all? Or maybe recal. the TPS?