I have an 83 toyota LC with an 04 5.3L Vortec out of a Tahoe. The wiring harness and computer (EPROM) came from Fuel Injection Specialties out of San Antonio... It is idleing high. I got codes P0507 another 02 code (cant remember # at this time). I've had this problem since the conversion two years ago. Measured resistance on the IAC and it measured 58 ohms, I cleaned it with carb cleaner, re-installed, cleared codes and now it idles even higher. Pulled the IAC again and it measured 48 ohms, went a junk yard bought another one for $20, it too measured 48 ohms. Wagon still idles way high - it can run at about 35mph on its own on 4th gear. One other thing I noticed yesterday after I swapped the IAC i got at the junk yard is that I can hear the aftermarket Spectre airfilter sucking in massive amounts of air. I hear it from inside the cab and it comes and goes as I am driving. It was not doing this before I swapped IAC's. Hope all this makes some sense...
Any other suggestions? Any good place here in Austin where I can get an honest pro to diagnose the problem?