454 Vortec Runs Poorly... (With FP readings)

Discussion in 'Engine Performance + Maintenance' started by BratRod, Aug 6, 2017.

  1. BratRod

    BratRod Newbie

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    Another dreaded Vortec fuel pressure thread... Yeah, yeah. If this was CSFI I wouldn't be asking but I've never dealt with the big motor so here goes.

    Truck does not accelerate worth a damn. I'm getting about 8mpg, which is less concerning. Does not have a hot start or cold start issue.

    The question is spark or fuel...

    Fuel pressure test results are as follows:

    KOEO initial: 40psi (if I cycle the key several times I can get it up to 48)

    Bleed off test: Does not drop at all. Actually raises presumably from the heat. Gets up to 50 after a few min.

    KOER: 38PSI

    Steady 2500 idle: 34PSI

    Wot while driving drops between 25-30psi

    This seems really low to me. But I'm surprised it even starts? Hooked the gauge up to my S10 to make sure the gauge is fine.

    I just replaced the fuel filter as a maintenance item. But this problem has existed since I bought the truck.

    I'm thinking I'm gonna replace the fuel pump regardless. Just wanted your input.

    Thanks in advance

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  2. Supercharged111

    Supercharged111 I'm Awesome

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    Yeah I'm pretty sure it's a 4 bar system just like the small block. Check the ground for the pump first, maybe corroded?
     
  3. BratRod

    BratRod Newbie

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    New oem pump woke her right up. Ground was also not in the best shape, so I took care of that.

    cheers

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