we have a 1992 f150 5 litre 5 speed, we are having problems with engine not idling.
have replaced the egr valve, the intake manifold gasket, iac sensor, throttle positioning sensor.
When you start it up in the morning, engine reves high, does not return to an idle automatically. when engine is warmed up, engines reves when shifting gears and engine chugs as if it was flooding at an idle. if you unplug the iac sensor, engine returns to proper idle.
my husband has already cleaned the throttle plate., but has not checked voltage readings yet. We are having a heat wave here in Ontario right now, staying in air conditioning as much as possible., but will let you know what happens with the readings,
thanks once again for your support.
Originally Posted by rtg143
Those are the readings at the gray/white wire. Have you cleaned the throttle plate?
Last edited by 99mallard; 07-06-2010 at 20:00.
Reason: add a line
my husband did voltage test, everything was fine except map sensor is suppose to read 5 volts with no vaccuum, and only reads 2.5 volts., could not test with vaccuum, because dont have a vaccuum pump at this moment, will have one tomorrow to test.
he also checked that there was voltage from the computer to the sensors.
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