Put new IAC valve on. Calibrated to specs before install. Very high idle in park and rpms around 1500 to 1800 when driving. Drove long enough for ecm to do what it should but still the same problems. Disconnected positive terminal and grounded for about 30 seconds and still high idle. Any suggestions?

 

What exactly did you do to *calibrate* the new IAC stepper motor?

 

vacuum leak

 

My thought exactly. Check any vacuum hoses around the throttle body, like the heater vacuum supply.

 

For that matter check the throttle body itself to see if is loose. 4 bolts as I recall. Intakes have been known to be replaced with the wrong ones, resulting in leaks and high idle also.

 

Thanx for the suggestions guys. I know its 1 and a half months later. I am still trying to figure out how to do everything on this forum.
Anyways, I found the problem with that IAC about a day after I opened this thread. I kept seeing you guys says "keep it simple stupid" on this site so I went and checked the wiring to new IAC. Turns out bottom pin on back of the "wire harness" (I believe it is called) that snaps into thottle valve was actually push out about a half a centimeter.
Once I pushed it back in nice and snug for a good connection everything worked great.

 

Glad to hear it's resolved.