Fuel pump not shutting off

Discussion in 'Chevy Truck Forum' started by Steven Davis, Jan 13, 2018.

  1. Steven Davis

    Steven Davis New Member

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    I have a 93 Silverado 5.7 the fuel pump will not shut off when the truck is turned off in the key out I have replaced the fuel pump relay and I have replaced the oil sending unit not sure what to do next it is running the battery down
     
  2. MikeG

    MikeG Full Member

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  3. MikeG

    MikeG Full Member

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  4. hatzie

    hatzie Full Member

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    Have you tried unplugging the Hot Fuel Handling relay?
    It's there to prevent vaporlock by running the fuel pump for 20 seconds after key off when the outdoor temps are high.
    If it malfunctions the fuel pump can run without the ignition switched on.

    1993 CK series service manuals folder --->MediaFire 1993 T400 Manual Folder
    Look in the 1993 GM CK wiring manual on PDF page 272 for the hot start relay location.
     
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