Not idling properly and continually stalls and won't stay running.

MILEE777

MEMBER
1988 FORD F-150
6 CYL
2WD
MANUAL
150,000 MILES

The truck is not idling properly and continually stalls and won't stay running. This started about two weeks ago and I have tried replacing the fuel pump, fuel pressure regulator and the spark plugs. I am now lookng at replacing some of the wiring. Before this started, the truck ran great. There has been only one owner who took meticulous care of the vehicle before it was sold to me 2 months ago. Any assistance you could offer would be greatly appreciated.

Sunday, August 10th, 2008 AT 10:29 AM

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

Sounds like the issue could be with the idle air control valve, also known as air bypass valve for these Ford trucks.
That valve is located on the throttle body.
It controls the idle speed of the engine, and a malfunctioning or dirty bypass valve can have similar drivability issues that you have been experiencing.
Over time larger air particles can get stuck to the inside of the valve and crease air flow restrictions. This can lead to poor idle or engine stalling at idle.

Cleaning out the valve can improve the idle quality.

Here is a helpful guide:

https://www.2carpros.com/articles/idle-air-control-valve-service

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.

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