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Thread: 1988 GMC 1500 no pwr to fuel pump

  1. #1
    Join Date
    Apr 2008

    Unhappy 1988 GMC 1500 no pwr to fuel pump

    88 GMC 1500 4X4 no power is getting to the fuel pump, I have replaced the pump, and the pump relay, I have also check the harness going from the pump to the PCM, This truck is carbureted but used to be throttle bodied. I just bought the truck and I have run out of ideas. When gas is poured into the carb she will fire and run right up until the gas is gone so i know i have spark. Any Ideas? She ran fine one minute shut her off and then didnít start afterwards.

    Thank you.

  2. #2
    Join Date
    Jan 2007


    NEd1208 - Make sure you have power coming out of th erelay and all the way to the pump. If there is power you have a ground problem since somebody did a conversion you will need to see where the grounds are and if the ECM is properly grounded. If there is no power to the pump but power from the realy you have a bad wire.

    Good luck this is a tough one. Let us know what you finally find.

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