99mallard

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.

could this be the coolant temperature sensor???

any help would be appreciated.

99mallard

Bert

Run this test and see if you get any codes. Ford Fuel Injection � How To Run a Self-Test

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Bert

99mallard

Hi,

we did the self test, and got codes like 41 and 63, but in the book that we have it sez these codes are for years 1991 and earlier, and 1992 should have 3 digit codes?>>

any suggestions

thanks

Bert

According to the Ford shop manual, your truck has 2 digit codes and the cars had 3. The TPS is below .6 volts and the O2 sensor showed lean. Could be connection problems. I'll have to search further.

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Bert

99mallard

Thank you so much for your help. look forward to hearing from you soon.

99mallard

Bert

The gray/white wire sends the signal. Here's what the readings should be.

Throttle Angle Voltage
Idle 0.95 V
20° 1.44 V
30° 1.90 V
40° 2.37 V
50° 2.84 V
60° 3.31 V
70° 3.78 V
80° WOT 4.24 V

You can also clean the throttle plate and try a new TPS. After the code 63 is fixed, then run it awhile and see if the 41 comes back

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Bert

99mallard

Hi,

i;m not quite following what you wrote below? is there another test to be done?

also we have already replaced the tps about a month ago??

Thanks
99mallard

Bert

Those are the readings at the gray/white wire. Have you cleaned the throttle plate?

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Bert

99mallard

hi,

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.

99mallard

99mallard

hi,

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.

any thoughts??

99mallard