Fuel Pump Problems

blue302 · 11-25-2002, 02:23 PM

My stock fuel pump on my 1989 GT just stop working this weekend. I'm not sure if the fuel pump died on me or if I have some electrical problems. One thing that I do know is that my fuel pump does not turn on, because It does not make that humming sound that it always does when it was on. My question is, before I decide to bring down the fuel tank, does anyone know the color coding to the fuel pump wiring. I was able to find a 4pin connection, on the underside of my trunk. These wires goes towards my fuel tank and I'm assuming that it leads to the fuel pump. The wires have the following color code: Yellow,Red, and Two Black. I found voltage on my Red wire when I turn the ignition on, but found zero volts on the yellow wire. Should the yellow wire have any voltage present, assuming that the black wires are my grounds? Is there any fuses or fuse links that I should be looking for? Does the computer control the fuel pump? Any help would be greatly appreciated to get my Pony out of its coma.

Thanks

WADS56 · 11-25-2002, 02:31 PM

Chances are that it is a bad relay. Check under the drivers seat for it.

Wade

89MustangGTFox · 07-08-2005, 07:26 AM

There is a fuse link to the fuel pump, im not sure exactly where it is but if your battery jumped it could have possibly blown which would incapacitate your fuel pump so it might be that simple. Also if the car was bumped or hit...or if you slammed the hatch/trunk too hard...the fuel pump disengage button may have popped..this is for safety reasons in an accident...you simply open the trunk/hatch and look for that white button and push it back down, however, your car probably wouldnt start if it was disengaged...not much else i could think of electrical although you never know with this car im in the middle of an electrical mess myself right now >)

racerboy88 · 07-08-2005, 10:18 PM

the holley fuel pump is good, that's what I went with and it came with everything. Job took about 21/2hrs without a hoist

11-25-2002, 02:23 PM	#1
blue302 Registered Member Join Date: Feb 1999 Location: Los Angeles, CA, USA Posts: 28	Fuel Pump Problems My stock fuel pump on my 1989 GT just stop working this weekend. I'm not sure if the fuel pump died on me or if I have some electrical problems. One thing that I do know is that my fuel pump does not turn on, because It does not make that humming sound that it always does when it was on. My question is, before I decide to bring down the fuel tank, does anyone know the color coding to the fuel pump wiring. I was able to find a 4pin connection, on the underside of my trunk. These wires goes towards my fuel tank and I'm assuming that it leads to the fuel pump. The wires have the following color code: Yellow,Red, and Two Black. I found voltage on my Red wire when I turn the ignition on, but found zero volts on the yellow wire. Should the yellow wire have any voltage present, assuming that the black wires are my grounds? Is there any fuses or fuse links that I should be looking for? Does the computer control the fuel pump? Any help would be greatly appreciated to get my Pony out of its coma. Thanks __________________ 89GT:Edelbrock intake,BBK Shorty Headers, BBK 70mm TB,BBK Aluminum Pulleys, Adj. Reg. Edelbrock Water Pump,Griffin Aluminum Radiator, SVO Hoses, BBK H-Pipe w/conv.,Flowmasters 2Ch, SVO 3.73 w/Auburn Diff.,95 Cobra Front brakes and Lincoln Cont. rear disc brakes and 98 cobra rims.

11-25-2002, 02:31 PM	#2
WADS56 gear banger Join Date: Aug 2000 Location: CHICAGO Posts: 1,144	Chances are that it is a bad relay. Check under the drivers seat for it. Wade __________________ 79 Hatch: NA 347, Stage 2 Canfield Heads, Victor JR. Intake, Blueprinted Holley 750 HP, Solid Roller Cam, Shooting for 10's on motor 93 LX: Tremec, dual friction clutch, fms flywheel, Hedman shorties, O/R H-pipe Ricer hater's club member #49

07-08-2005, 07:26 AM	#3
89MustangGTFox Registered Member Join Date: Jul 2005 Posts: 1	Re: Fuel Pump Problems There is a fuse link to the fuel pump, im not sure exactly where it is but if your battery jumped it could have possibly blown which would incapacitate your fuel pump so it might be that simple. Also if the car was bumped or hit...or if you slammed the hatch/trunk too hard...the fuel pump disengage button may have popped..this is for safety reasons in an accident...you simply open the trunk/hatch and look for that white button and push it back down, however, your car probably wouldnt start if it was disengaged...not much else i could think of electrical although you never know with this car im in the middle of an electrical mess myself right now >)

07-08-2005, 10:18 PM	#4
racerboy88 Registered Member Join Date: Sep 2003 Location: British Columbia Posts: 123	Re: Fuel Pump Problems the holley fuel pump is good, that's what I went with and it came with everything. Job took about 21/2hrs without a hoist __________________ 1990 5.0 LX H/B H-pipe w/ flowmasters, Koni shocks and BBK springs.

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