1994 Ford F-150 FUEL PUMP CONSTANTLY RUNNING

ROBERTNMISTY

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1994 FORD F-150
6 CYL
4WD
AUTOMATIC
200,000 MILES

FUEL PUMP CONSTANTLY RUNNING WHEN STARTS RUNS ROUGH BLOWS BLACK SMOKE WHEN YOU HEAR THE FUEL PJMP STOP RUNNING STARTS AND RUNS FINE CHANGED FUEL PUMP 6 MONTHS AGO ONLY ONE TANK ON TRUCK WHATS THE PROBLEM PLEASE HELP

Monday, February 9th, 2009 AT 9:41 PM

4 Replies

DAVE H

MECHANIC
13,383 POSTS

Fuel Pump Actuation
When ignition switch is turned to START position, PCM operates fuel pump relay to provide fuel for starting engine. PCM 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. When ignition switch is in ON position, EEC power relay is energized (contacts closed). Power is provided to fuel pump relay and timer in PCM. Fuel pump receives power through fuel pump relay contacts.

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Monday, February 9th, 2009 AT 9:48 PM

ROBERTNMISTY

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2 POSTS

SO WHAT DO I NEED TO DO TO FIX PROBLEM IS IT THE PRESSURE REGULATOR

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Monday, February 9th, 2009 AT 9:53 PM

DAVE H

MECHANIC
13,383 POSTS

If the pump is constantly running you need to check/replace the fuel pump relay first. The PCM(computer) and the EEC relay supply power/grounds to the pump !

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Monday, February 9th, 2009 AT 9:58 PM

ROBERTNMISTY

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Bad cumputer in truck have to change took cumputer I had for 94 ford f250 v8 plugged up fuel pump woked perfect motor ran bad not programed for truck will get the right one thanks for the help

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Friday, February 13th, 2009 AT 10:52 PM