Fuel pump will not shut off
Asked by Reddog3696 Jan 22, 2016 at 04:25 PM about the 1989 Ford F-150 S Standard Cab 4WD SB
Question type: Maintenance & Repair
Turn switch on and fuel pump runs for a few seconds. Then cuts off.
Mine keeps running.
6 Answers
Suspect the fuel pump relay. Normally the fuel pump relay operates during starting and when turning off the engine. If it is stuck, the pump could continue to run. A full explanation of how the relay works and how to check it is quite long. I suggest you check the net for info on how a fuel pump relay works and conduct the electrical test. It is straight forward. Basically, if the relay is sending power to the pump with the engine off, it is defective.
Fuel Relay contact stuck closed. Replace relay
My 92 Bronco would do the same. I had to ether start it, then it would run. Problem ended up being the capacitor’s in the ecm. Ordered new ecm from autozone(Cardone) for $90 and boom. Starts and runs like a champ. Another side issue was also fixed. Trans would not take off in first.
Chatsworth answered 4 years ago
Mine was the ecu...didn't open it up but had a burnt smell. Replace ecu now runs better then it has in years.