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  1. #1
    I'm Awesome Fast 95's Avatar
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    Default How much fuel pressure for a 5.7 vortec?

    How much fuel pressure should i have for a 96 5.7 vortec?


    1/4 mile ET 12.43 @ 110 mph

  2. #2
    I'm Awesome 6chevy9's Avatar
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    i belive i read somthing that said 60-65 psi but i could be wrong ill take a look. i think i saw that on GMFS. if i find it ill post a link or the info
    97 rcsb 355cid DIY cold air intake throttle body spacer home made exhaust 3 inch body lift keys add a leaf and 33/12.50 bfg mud SOLD!

    98 gmc ecsb, 16.5 inches of lift. 454, 4l80, Dana 60 40" tires.

  3. #3
    I'm Awesome Fast 95's Avatar
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    That would be great, i dont want to spend $100 if i dont have to.


    1/4 mile ET 12.43 @ 110 mph

  4. #4
    I'm Awesome 6chevy9's Avatar
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    yes that was correct as far as everything i have read

    copy and paste from another site

    Your reading was done at idle. GM lists no fuel specs with the engine running. Below is the GM test procedure and spec:

    FUEL PRESSURE



    Ignition "OFF" for 10 Seconds.
    With ignition "ON," engine "OFF" and fuel pump running, pressure should be 415-455 kPa (60-66 psi).
    97 rcsb 355cid DIY cold air intake throttle body spacer home made exhaust 3 inch body lift keys add a leaf and 33/12.50 bfg mud SOLD!

    98 gmc ecsb, 16.5 inches of lift. 454, 4l80, Dana 60 40" tires.

  5. #5
    I'm Awesome Fast 95's Avatar
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    I'm only getting 57 psi with the key on engine off, and it drops to 50 psi while running.


    1/4 mile ET 12.43 @ 110 mph

  6. #6
    Administrator Deluxe Mike's Avatar
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    You should be ok with that, no matter what your pressure do that engine will be starved for fuel until you switch to a real injection system.

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  7. #7
    I'm Awesome 6chevy9's Avatar
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    i also dont see that being your miss fire problem, unless one injector is pluged or somthing but you said you replace/ cleaned them i belive already so i dont see that being a cause.
    97 rcsb 355cid DIY cold air intake throttle body spacer home made exhaust 3 inch body lift keys add a leaf and 33/12.50 bfg mud SOLD!

    98 gmc ecsb, 16.5 inches of lift. 454, 4l80, Dana 60 40" tires.

  8. #8
    Nooo! Noooooo MIHELA's Avatar
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    57 is not enough to overcome the poppet nozzles on the Vortec. That is definitely your problem.
    "Steve" - 1995 Chevrolet Silverado - Starline westerner conversion package
    4WD, 5.7 TBI, 5 speed manual, Z-71 package, 14 BSF, E-fans

  9. #9
    I'm Awesome Fast 95's Avatar
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    Quote Originally Posted by MIHELA View Post
    57 is not enough to overcome the poppet nozzles on the Vortec. That is definitely your problem.
    Its 57 with the motor not running, once started its 50 psi, and i do have the upgraded spider injectors as well.


    1/4 mile ET 12.43 @ 110 mph

  10. #10
    Nooo! Noooooo MIHELA's Avatar
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    OK, then that's probably not it. The poppets are very sensitive to low pressure.
    "Steve" - 1995 Chevrolet Silverado - Starline westerner conversion package
    4WD, 5.7 TBI, 5 speed manual, Z-71 package, 14 BSF, E-fans

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