Register to remove these ads

How much fuel pressure for a 5.7 vortec?

Discussion in 'Engine Performance + Maintenance' started by Fast 95, Mar 24, 2010.

  1. Fast 95

    Fast 95 I'm Awesome

    Messages:
    204
    Likes Received:
    1
    Joined:
    Dec 14, 2009
    How much fuel pressure should i have for a 96 5.7 vortec?
     
  2. 6chevy9

    6chevy9 I'm Awesome

    Age:
    28
    Messages:
    1,243
    Likes Received:
    4
    Joined:
    Jan 14, 2010
    Location:
    pinckney mi
    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
     
  3. Fast 95

    Fast 95 I'm Awesome

    Messages:
    204
    Likes Received:
    1
    Joined:
    Dec 14, 2009
    That would be great, i dont want to spend $100 if i dont have to.
     
  4. 6chevy9

    6chevy9 I'm Awesome

    Age:
    28
    Messages:
    1,243
    Likes Received:
    4
    Joined:
    Jan 14, 2010
    Location:
    pinckney mi
    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).
     
  5. Fast 95

    Fast 95 I'm Awesome

    Messages:
    204
    Likes Received:
    1
    Joined:
    Dec 14, 2009
    I'm only getting 57 psi with the key on engine off, and it drops to 50 psi while running.
     
  6. Mike

    Mike Administrator Deluxe Staff Member

    Messages:
    1,587
    Likes Received:
    14
    Joined:
    Dec 2, 2009
    Location:
    Mass.
    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.
     
  7. 6chevy9

    6chevy9 I'm Awesome

    Age:
    28
    Messages:
    1,243
    Likes Received:
    4
    Joined:
    Jan 14, 2010
    Location:
    pinckney mi
    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.
     
  8. MIHELA

    MIHELA Nooo! Noooooo

    Messages:
    499
    Likes Received:
    2
    Joined:
    Dec 9, 2009
    Location:
    Sioux Falls, SD
    57 is not enough to overcome the poppet nozzles on the Vortec. That is definitely your problem.
     
  9. Fast 95

    Fast 95 I'm Awesome

    Messages:
    204
    Likes Received:
    1
    Joined:
    Dec 14, 2009
    Its 57 with the motor not running, once started its 50 psi, and i do have the upgraded spider injectors as well.
     
  10. MIHELA

    MIHELA Nooo! Noooooo

    Messages:
    499
    Likes Received:
    2
    Joined:
    Dec 9, 2009
    Location:
    Sioux Falls, SD
    OK, then that's probably not it. The poppets are very sensitive to low pressure.
     

Share This Page