I just got done replacing my IAC Sensor on my '93 Z because it wouldnt idle upon start up. Well, it now idles fine...but a little too high. Idles around 1100-1200 rpm and when i rev the car, it will go up to 2000rpm and stay for a sec, then to 1500rpm and stay for a second..then back to 1100 or 1200. I adjusted the idle screw thats on the TB and it really only helps if i push the plate against the screw...its like the plate wont go against the screw. Anyone got any ideas?

 

You really should never have to touch the throttle stop screw. Did you give the computer enough time to relearn the idle speed? The pintle setting can be off when you install a new IAC. You can try resetting it by:

-Depress accelerator slightly

-Start engine, then release accelerator pedal, run engine for 5 seconds

-Turn ignition "OFF" for ten seconds

-Restart engine and check for proper idle operation