+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 10 of 11

Thread: Perhaps Too Much Fuel Pressure?

  1. #1
    Join Date
    Jul 2014
    Location
    Boise, ID
    Posts
    65

    Post Perhaps Too Much Fuel Pressure?

    I still have, for the most part, a stock 5.3 from a 2008 Tahoe in my 88 K5 Blazer, so we're talking 330 to 350hp at most. I do have some JBA headers that give it a little more, but not much.

    Anyway, I have a pump I bought from Summit that dropped into the Blazer's stock sending unit fine, and I've been running it for about 7 months now. It puts out 90 psi, and I've always noticed that the truck is running rich. I think this is bad (Disclaimer: I'm not a professional mechanic!)

    Is 90 psi for my setup too much? Can/will this cause problems, and if so, what?

  2. #2
    Join Date
    Apr 2014
    Posts
    162
    What is the fuel pressure at the rail? The regulator should kick it down where it belongs unless the pump is just flat over coming the regulator.

  3. #3
    Join Date
    Jul 2014
    Location
    Boise, ID
    Posts
    65
    Pressure at the rail:

    (key turned but engine not started is 55psi)
    (Engine started is 90psi)

  4. #4
    Join Date
    Mar 2003
    Location
    San Marcos Texas
    Posts
    4,442
    60 is about right. 90 is too high.

  5. #5
    Join Date
    Jul 2014
    Location
    Boise, ID
    Posts
    65
    Thanks! Looks like I'll be dropping the tank again here shortly.

  6. #6
    Join Date
    Aug 2005
    Location
    St. Anthony, Indiana
    Posts
    1,595
    Are you using a fuel pressure regulator?

  7. #7
    Join Date
    Jan 2016
    Location
    Idaho
    Posts
    6
    Too much pressure unless you're running a lot more HP than stock. I don't know what harm it would do other than run rich and throw o2 errors.

  8. #8
    Join Date
    Jul 2014
    Location
    Boise, ID
    Posts
    65
    Quote Originally Posted by foggy View Post
    Are you using a fuel pressure regulator?
    Yes. Got a corvette/wix regulator hooked in shortly after leaving the tank. The rail on my motor doesn't have one built in - some didn't in 2008.

  9. #9
    Join Date
    Jul 2014
    Location
    Boise, ID
    Posts
    65
    Quote Originally Posted by GotaluvHP View Post
    Too much pressure unless you're running a lot more HP than stock. I don't know what harm it would do other than run rich and throw o2 errors.
    That explains the engine running rich - no codes tripping, though.

  10. #10
    Join Date
    Aug 2005
    Location
    St. Anthony, Indiana
    Posts
    1,595
    Quote Originally Posted by 88blazerboy View Post
    Yes. Got a corvette/wix regulator hooked in shortly after leaving the tank. The rail on my motor doesn't have one built in - some didn't in 2008.
    I would think that you have a bad regulator than. It should regulate it to about 60 psi.
    How is your fuel system set up?

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts