Mechanics

F150 COLD START AND IDLING

1987 Ford F-150

Engine Performance problem
1987 Ford F150 6 cyl Four Wheel Drive Manual 200000 miles

The truck will start with no problem.

It will not idle after being started until the engine temp. Is hot.

If I sit in the truck and pat the accelerator or hold the rpm at 1200 the engine will continue to run.

If I do not pat or hold the accelerator the engine will surge about five times and then stop running.

I have changed the Idle by pass valve, the throttle position sensor, and the coolant temperature sensor.
I have also changed the MAP sensor with no change to the engine operation.

After the engine get hot it will idle and run like new.

Any suggestions to resolve this situation.

Thanks is advance.
Avatar
Fordtruckster
December 5, 2008.




Have you checked the intake air temperature sensor, that can cause a issue also.

Also you could have a leak on the intake that is causing the vehicle to run rough when cold but when the engine heats up and the metal expands it closes the leak off.

Blackop555
Dec 6, 2008.


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