Mechanics

F150 DUAL FUEL SYSTEM

1989 Ford F-150

Engine Mechanical problem
1989 Ford F150 V8 Four Wheel Drive Manual 105499 miles

Switching to front gas tank causes engine to die after a few moments. Is the probable cause the front fuel pump or are the tanks dependant systems, one pumping fuel into the other?
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Bshwacker
May 16, 2009.



It is the fuel pump in that tank. See how it works is there is a pump in each tank (lift pumps) then there is a switch valve and the high pressure pump on the frame and infront of that the fuel filter. So what happens when you select the tank it turns on that pump in that tank and that move a check ball in the switch valve so the fuel returns back to the right tank and lifts the fuel to the pressure pump as well. If one of the intank pumps go bad then it dies shortly after you switch tanks.

Racefan966
May 20, 2009.