My fuel pump is not working?

Tiny
JENNIFER.M.ROBINSON
  • MEMBER
  • 2004 PONTIAC GRAND PRIX
  • 6 CYL
  • AWD
  • AUTOMATIC
  • 99,000 MILES
I have had my car now for 5 years now and about a year ago my fuel pump went out had it replaced and about a week after that it stalled on me again and had the issue taken care of said it was a loose wire. Well almost exactly a year now and it is happening again. Why is my fuel pump not working?
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Monday, August 2nd, 2010 AT 3:00 PM

39 Replies

Tiny
MMPRINCE4000
  • EXPERT
Running the car out of gas will cause premature pump failure. You should also change strainer on bottom of pump, when replacing pump. Let check the power to the pump and check the relay (#41) and fuse here is a guide to help with the fuel pump wiring diagrams and relay locations below so you can see how this system works.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

and

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the diagrams (Below). Let us know what happens and please upload pictures or videos of the problem.
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Saturday, August 7th, 2010 AT 8:22 AM
Tiny
JAMES5227
  • MEMBER
It was the fuel pump relay for me. Thanks for the post.
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Saturday, March 20th, 2021 AT 7:15 PM
Tiny
RYANFND
  • MEMBER
  • 2000 PONTIAC GRAND PRIX
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 114,000 MILES
My fuel pump just quit, will not turn on. The fuse is okay and so are the mini relays. Two plug in on top of my fuel pump and with my key forward one wire on each plug gets about 5 volts. Is my pump Shot?
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT
Most likely but you can supply 12v direct power to the pump to see if it runs that way, if not its defniitely bad.
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
RYANFND
  • MEMBER
Where would I apply 12 volts directly to on my fuel pump? There are two plugs on the top of it.
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT
Black/white and purple wires are for the fuel level sensor. The grey and black wires are the fuel pumps, black being ground and grey being power.
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
DLOWERY513
  • MEMBER
  • 2000 PONTIAC GRAND PRIX
  • 3.1L
  • V6
  • FWD
  • AUTOMATIC
  • 150,000 MILES
I replaced the fuel pump relay in fuse box, checked all fuses are ok, I replaced the fuel pump still I hear NO pump priming or running, Could this be the fuel pump resistor? And can I test the power to the pump and the resistor before replacing the resistor? Any help would be most appreciated, I can't afford dealer prices. Thank you POOR
ole boy .
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
First, check to see if there is power to the pump. If there is, check for a bad ground. The pumps go out all the time in these cars here is a guide to show you what you are in for when doing the job and diagrams to show you what it will be like for your car.

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

Check out the diagrams (Below). Please let us know what you find.

Cheers
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
DLOWERY513
  • MEMBER
I replaced the pump, engine started right up I love this site. Thanks again.
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Good to hear, please use 2CarPros anytime we are here to help.

Cheers
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
PATBUSGUY
  • MEMBER
  • 2000 PONTIAC GRAND PRIX
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 98,000 MILES
Car runs ok cold. New fuel pump stops running after 10 min. Pump relay looses signal to stay closed. How can I test pump resistor. That is, what range of resistance should my ohm meter show? What else can shut off control circuit to fuel pump? Thanks, Jim
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
MMPRINCE4000
  • EXPERT
Many GM cars have a backup oil pressure circuit for the fuel pump, that is, if FP relay goes bad, once oil pressure is above 10psi, the oil pressure circuit will run pump.
Conversley, if OP circuit is bad (low pressure) pump will shut off.
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
JGRIFFIN1955
  • MEMBER
  • 1999 PONTIAC GRAND PRIX
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 12,000 MILES
I have a 1999 Pontiac Grand Prix GTP. The fuel pump has been shutting down intermidently. Found the voltage at the pump was dropping and eventually shutting down after many hours of monitoring. I have now replaced the fuel pump resistor with and new GM part and relocated. Car has not stalled as of this time, but the pump voltage still seems low. 10- 11 volts cold and 9-10 volts hot. Drops as time progresses and the resistor heats up - the new resistor still gets very warm - almost hot. Can the pump be pulling too many amps and causing the resistor to heat up and eventually shut the pump down?
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
2CEXPT
  • MEMBER
Its the fuel pump and oil pressure switch that powers the fuel pump after it fires up
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
2CEXPT
  • MEMBER
Double check the ground circuits one (1) at the transaxle stud G129 and one (1) at right door sill G316-makes sure its clean and free of corrosion
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
CRAIG92481
  • MEMBER
  • 1998 PONTIAC GRAND PRIX
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 90,000 MILES
3.8L fuel pumps prime on key on and after engine dies. Checked all fuses and swaped both pump relays no change. After pump prime pressure is 55 psi car will run for 15 sec. Then dies then pump turns back on to prime system. Engine has no codes, and no know problems. Removed cover to access pump wiring and test light lights durring prime but dose not light when engine is running. Made a jumper and turned on fuel pump and car runs ans nothing wrong. Tested plug and still no power at the pump when car is runnig. I thing the main question is what turns the pump on when engine is running, (ecm, and switches, sensors?)
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
The PCM is what tells the relay when to send power to the fuel pump. Have you checked for poor terminal connection between the fuel pump relay control circuit and the PCM? Also, using a test light connected to ground, check to see if you are getting power to the ignition feed circuit at the relay. If you are, recheck the contacts to the relay.

Let me know what you find.

Joe
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
CRAIG92481
  • MEMBER
After checking the pump and testing several sensors found a ressistor in the right side in the wheel well above the washer fluid bottle was bad. GM has a updated part and location for this ressistor. The way I think this system works is full power, batt voltage to the pump on the prime and when the boost reaches a set level in the computer. All other time the sytem run on a lower voltage when the deman for fuel is lowwer.
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
That is correct. I'm glad you got it figured out. Let us know in the future if you have any questions, and thanks for using 2carpros. Com
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)
Tiny
CRAIG92481
  • MEMBER
Did you know about the resistor, and what would be the real reason for it
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Saturday, March 20th, 2021 AT 7:31 PM (Merged)

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