77crewcab
05-08-2006, 09:28 PM
I am having trouble with a low idle on my 90 3.0. This started after unplugging the MAP sensor while changing the thermostat. When starting it wil die unless I rev it for a few seconds and then will idle at 600 rpm. It will also drop back to 600 or lower rpm if I let off the throttle suddenly and then die. Overall it just doesn't seem to be running as before below about 2500rpm. Before I replace the MAP sensor which I believe to be the culprit as the problems started after uplugging it could there be other causes? No codes BTW.
mcmotors
05-08-2006, 10:03 PM
I would try to disconnect the battery for a few minutes, while waiting for the computer to reset, take the intake air off the throttle body and give it a good cleaning with carb or brake cleaner. Make sure the vaccum hose that goes to the map sensor is not cracked or porous. Reconnect the battery and start the vehicle without touching the accelerator, leave it at idle for a minute or so before reving and retesting. Maybe someone can think of something else...
I can't remember for sure (I have 1 with a 3.0 the other with a 3.8), if the thermostat is near the distributor, you may have water on the cap or wires...
