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  • 4 Post By 34_40
  • 2 Post By DennyW

Thread: Fuel Pump Question
          
   
   

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  1. #1
    39 Chevy is offline CHR Member Visit my Photo Gallery
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    Fuel Pump Question

     



    I got a 55 Chevy truck that I am working on. It had a stock 350 an I have put a 383, 430 hp. Someone put a electric fuel on it so I just left it on there. Cranks good idles good bout 6 psi give gas it drops down to bout 4 psi. Bad pump or just not enough GPH ?

  2. #2
    DennyW is offline CHR Member Visit my Photo Gallery
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    -------------------------
    Last edited by DennyW; 03-01-2019 at 07:14 AM.

  3. #3
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    34_40 is offline CHR Member Visit my Photo Gallery
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    Car Year, Make, Model: 34 Ford 3W Coupe Replica
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    Not much information really but, assuming it's a quadrajet or holley. 4 psi is all you really need for average driving. The pressure drop could be many things. Undersized fuel lines, hoses, perhaps a kink or dirty filter/ sock in the tank...

    But unless you're towing or doing long stretches of wide open throttle, I'd doubt you'll notice the carb starving.

  4. #4
    39 Chevy is offline CHR Member Visit my Photo Gallery
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    It has a Holley DP, 3/8 fuel line. Round cylinder type pump mounted right above the tank.

  5. #5
    DennyW is offline CHR Member Visit my Photo Gallery
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    I would say you are good...

    FUEL PRESSURE:
    This carburetor has been designed to work best at fuel pressures between 5 and 7 psi.
    Holley recommends 7 psi at idle, and a minimum 4 psi at engine redline.
    Three 8” fuel lines can result in adequate (indicated) fuel pressures, but restricted fuel flow.
    Use of a Holley electric fuel pump at the rear of the vehicle next to the fuel tank assures adequate fuel pressure under even
    the most severe operating conditions.

    So, if you have 4psi on top end, you should be just fine. 6 psi at idle, is fine also.
    If you want more flow, simply go to 7/16" fuel line. If there is no problems, I would say, drive it and have fun.
    NTFDAY and t-top havoc like this.

  6. #6
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    martinbrown79, how about at least a little information... OK, we know it's a chevy. How about year, model, motor size, tranny. Carbed or F.I.?

    When do you experience the problem?

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