TRUCK ACTS LIKE WANTS TO TURN OFF. No engine light on

Discussion in 'Engine & Drivetrain Tech' started by juanr_08, Nov 9, 2016.

  1. juanr_08

    juanr_08 Member

    Messages:
    744
    Hey cgm peeps need some help. I've noticed when I start the truck it sounds like it wants to die on me and then runs fine after a few seconds, but this is not a everyday thing, at times turns on fine with no issues, but when it happens sounds like its not shooting enough fuel. Maybe fuel pressure sensor? Should I try and give the throttle a good clean? New spark plug wires and plugs installed about 2 months ago.
    BTW its a 99 nbs 5.3
     
  2. dszx13

    dszx13 Well-Known Member

    Messages:
    5,426
    Be careful when cleaning throttle body. If you move the butterfly any you have to have it recalibrated.

    Sent from my SM-G935V using Tapatalk
     
  3. juanr_08

    juanr_08 Member

    Messages:
    744
    Thanks for the heads up man.
     
  4. ScottyBoy

    ScottyBoy The LED Man

    Messages:
    1,320
    If it stumbles like that mainly after the truck has been sitting for a while (overnight, or longer than that) then its a good chance its the fuel pressure regulator. Mine was doing that and I was about to replace it. But then I noticed that the vacuum line on the FPR was cracked. I replaced that line and its been working fine ever since.
     
  5. Khaos

    Khaos Bed Dent Club Founder

    Messages:
    20,302
    Check all your lines like scottyboy said. FPR can do it, or worst case scenario is you will replace the pump, which isn't too bad of a task.

    Emery19 just went though something similar with his 01 (02?) Tahoe with the 5.3.
     
  6. DirtyBlackHoe

    DirtyBlackHoe Bun B, Baracca, Beezer

    Messages:
    891
    When there was this issue on my brothers 2003 Tahoe it ended up being the FPR and the fuel pump.
     
  7. ScottyBoy

    ScottyBoy The LED Man

    Messages:
    1,320

    Now that you mention fuel pump. My fuel pump actually did fail about 2 months after the fuel pressure regulator was acting up. Were they related? Who knows. But I know that I only had an issue with hard starting and stumbling every once in a while, and it as always after my truck had been parked for at least 8-10 hours, and once I replaced the vacuum line for the fuel pressure regulator, it never happened again not once single time. My fuel pump did fail a few weeks later, but I honestly think it was unrelated. It didn't hesitate or anything, just went out like a light bulb. It was the original pump from 2001, so I guess 15-16 years on a pump is pretty good.
     
  8. Ginger

    Ginger Bubbles

    Messages:
    23,749
    i was gonna say fuel pressure related either regulator or pump
     
  9. wretched73

    wretched73 Member

    Messages:
    311
    Fuel pump has a check valve that should keep the pressure in the rail but that can fail over time. cycle your key twice and you can prime the fuel pump and get the fuel pressure back up.

    I'm not familiar with the 99 trucks and their fuel system so i can't comment on replacing the FPR
     
  10. juanr_08

    juanr_08 Member

    Messages:
    744
    I appreciate everyone, will look into it and see if any lines are cracked and might just change FPR just because truck is 17 yrs old lol
     
  11. ScottyBoy

    ScottyBoy The LED Man

    Messages:
    1,320

    That's EXACTLY what my thinking was. I was all set to jst ho ahead and replace the regulator, i even had it in my cart on Rockauto, i just didnt actually place the order. I went out to my truck and actually looked at the FPR and then that's when I saw that the vacuum line was cracked. I possibly cracked it when I replaced my knock sensors about a month or two prior to that, who knows. I just went ahead and replaced that vacuum line since I KNEW it was bad, and it started working fine. I still have the bag in my center console, I can grab the part number for that line if you need it. It was like $14 or so if I remember right.
     
  12. juanr_08

    juanr_08 Member

    Messages:
    744
    yea if you dont mind brotha
     
  13. ScottyBoy

    ScottyBoy The LED Man

    Messages:
    1,320
    Sorry it took me so long, but here it is. I honestly forgot all about it until I saw it in my center console again.

    [​IMG]
     

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