Hello!
I have a `93 Camaro, just installed LE2 heads and cam, 58mm TB, 30 lbs injectors. Chiptuning from PCMforless.
I cannot get IAC value under 90 by adjusting the throttle blades.
What can be the problem?
The car now acts that way:
At idle the IAC value is 90; rpm`s by the way are ca 1400 at this.
If I switch the gears, IAC increases to 160 and rpm`s falls to ca 700.
By driving the IAC falls to 90.
If I stop the car and let it idle, rpm`s jump to 1900.

 

Are you sure your IAC is moving? Just because the commanded count is changing, does not mean the actual IAC valve is moving.

 

I didnt see any difference if I pulled the IAC switch off or not. (I did it by standing engine, then turned it on) Also the IAC value is same.
Does it mean the IAC is broken?
Is there any other way to make it sure??
Thanks.

 

The IAC is a valve on the bottom of the throttle body. This valve is moved by a small stepper motor. Have you tried cleaning it? There is a way to check it also, by checking the resistance of the motor windings. I cant remember the pin out of the top of my head.