1991 Ford F150 V8 Four Wheel Drive Manual 206000 miles
I have been fighting a idle speed problem for a long time. I can cold start the truck and it will idle at 1100 rpm until it warms up and the idle will go down to 750 rpm. It will idle at this rpm for a few minutes and then will go to 3000 rpm and I haven't touched the truck. The upper plenum body was leaking air and I replaced the gasket. I have replaced the throttle position sensor, the air bypass control valve twice and the map sensor. I have replaced the plugs, wires, cap and rotor. This is a new crate engine with 6000 mil;es. Could this be the o2 sensor? I thought about changing the computer but I couldn't find it under the dash. Please help
have the same problem?
Saturday, January 3rd, 2009 AT 11:36 AM