IAC problems-possibly drivers?
IAC problems-possibly drivers? I have been trying to resolve a 2700 rpm idle problem. I posted on HP Tuners forum but didn't get much help. I was tuning the VE tables and for some unknown reason all of a sudden the car wants to idle at 2700. I restored the tune back to my original tune (when the car ran correctly). No change. I searched for vacuum leaks. None. I checked the IAC to make sure it was moving in and out, it was. I replaced the IAC with a known good but used one. No change. I pulled the intake and changed the gaskets, thinking it might be a vacuum leak underneath. No change. I took of the tube between my throttle body and air cleaner and partially blocked the hole that the IAC draws through. It idled down. I know now the air is all coming through the IAC but the ECU is not controlling it correctly. I have loaded multiple tunes and it reacts the same with all of them. I have read that the IAC drivers can go bad. Is this something I can check or reload in the ECU. I did a "Write Entire" with a known good tune. No change.Are the drivers built into the operating system. This is a 5.3 with an LS! intake and headers, stock cam. 1998 ECU. Any thoughts?
