Edmunds Answers



  • 0patience 05/26/10 11:59 pm PST

    When you say the fuel pressure is "kind of low", what exactly is it?

    What engine are we dealing with?

    But in the relay panel by the battery, is the fuel pump relay.
    If you give it a tap and the vehicle starts, replace the relay.
    If it doesn't start, then we need to know exactly what the fuel pressure is with the key on, engine off, it should be 60-66 psi.
    Then check it with the engine cranking. Let us know what you get.

    There is also a Fuel Pump Balance Relay is located on Fuel Pump Balance Module, inside LH Frame Rail, near Transmission Crossmember. Try the same thing with it.

    Use the Answer this Question button to reply.

  • sbleier 05/27/10 8:38 pm PST

    I swapped the horn relay with the fuel pump relay (they were the same) and nothing different.
    I checked the fuel pressure at the engine access port - no fuel coming out at all.
    I squirted some fuel into the carb and it ran for 4-5 seconds.

    I couldn't find the other fuel balence relay you talked about. I saw a brake power booster I think. but that was it.

    My engine is a 5.3L

  • chas47 01/21/13 8:59 pm PST

    I got the same problem! However my bed has been pulled off to let me get access to my fuel module. there are two electrical clips on the module. take a test light and ground it good to the frame. then find the electrical connector clip that has 4 wires and pull it loose from the module. find the grey wire push your tester point into that part of the plug. When you have someone turn the key on ( but dont crank it) the light should go on for 3 sec. then go out.Use a helper because the light goes off quick. If you have the light on you have power to your fuel module and it should start up. Unless you have a bad pump. Now my problem is I dont have power coming into my electrical plug but have put in a new relay ( its good tested it) Is something overriding it telling the relay to not send power to the pump. Now I did something I dont recomend to leave permanant I ran a hot wire from my battery to my plug turned on the key boom started right up!! Help me someone please

  • chas47 01/21/13 9:18 pm PST

    I took my 2000 silverado 5.3 l to get my alternator changed (bad) and when the guy was done with it It wouldnt start I had to tow it out of there. Did he fry something?? help

  • mwham2000 10/29/15 10:48 am PST

    Hope to answer this problem. 2000, Silverado, 2wd, 5.3..
    I had the same fuel pump problem and did most things as described above. I tried,
    1) Sprayed starting fluid to intake & truck started momentarily,
    3+/- seconds)
    2) Used aother battery to hook up gray(power) & Black(ground) to another plug that fit newly installed fuel pump and truck started and ran fine. While truck running on alternate battery found 14 volts to the gray wire terminal on existing fuel pump harness.
    3) Spliced in and grounded a new ground(black) wire.
    4) Old ground found later to be melted by mechanic during ABS brake work, an accident that took a little time to completely show up.

    I can only hope that safety is always top priority while dealing with fuel and power issues!!!
    The ground portion of automobile electrical circuit must be complete and treated as importantly as the power side.


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