I have a '92 mustang 5.0EFI and it started to idle at 2000 rpm and would not come down so I turned off the car and unplugged the IACV and it stopped. Then I bought a new IACV and plugged it in and it went right to 2000 rpm. What could this be? Also what is the setting for the TPS? I can't find it in any books. Any help would be greatly apprieciated.