Mechanics

F250 FUEL PUMPS

1990 Ford F-250

Electrical problem
1990 Ford F250 V8 Four Wheel Drive Automatic

I AM TRYING TO TEST OUT THE FUEL PUMPS IN THE TRUCK I AM GETTING NO PRESSURE AT THE FUEL RAIL. HOW DO I TEST FOR POWER GOING TO THE PUMPS
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DODGE69
March 15, 2010.



FUEL PUMP CONTROL
When ignition switch is in ON position, EEC power relay is energized (contacts closed). Power is provided to fuel pump relay and timer in ECA. Fuel pump receives power through fuel pump relay contacts. If ignition switch is not turned to START position, timer in ECA will open ground circuit, after approximately one second. ECA senses engine speed and shuts off fuel pump by opening ground circuit to fuel pump relay when engine stops or speed drops to less than 120 RPM.
Opening ground circuit de-energizes fuel pump relay (contacts opened) and de-energizes fuel pump. This allows fuel system to depressurize. When ignition switch is turned to START position, ECA operates fuel pump relay to provide fuel for starting engine while cranking

FUEL PUMP SHUTOFF SWITCH
This switch stops the flow of fuel to the engine after a collision. The impact does not have to be great to trigger the switch. To reset, press the white reset button on the switch located on the floorboard, to the left and above where the steering column passes through the floorboard.

Dave H
Mar 15, 2010.