Thank you Tayto
Yes the truck is still setup with TBI...The TB is not the issue, I have tried a few different setups. This is a real head scratcher I've tried everything except wiring harness stuff. Remember if I jumper the ALDL and drive the IAC closed, then unplug it and start it up it will idle at 500-525... plug it back in and start the truck.... and back to 900 it goes. Something is telling the IAC to open and all I can think is wiring resistance, short or ground. My next step is to build a new pigtail and run the four wires straight from the IAC to the computer and see if that helps