1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

5.9 randomly loses power and shuts off

Discussion in '5.9L 12 valve Cummins' started by H Olson, Feb 12, 2021.

  1. H Olson

    H Olson Registered User

    Posts:
    1
    Likes Received:
    0
    Joined:
    Feb 12, 2021
    Location:
    US
    I have a 5.9 in a 94 2500 with 384k miles, stock with the exception of bigger injectors and Airfilter. I have had zero issues in the 4 years I have had it, servicing is mostly on time with quality oil. Every tank gets fuel treatment so I don't believe that is the issue. The problem is it will randomly shut off and then will restart, it is getting worse and it will also lose power after getting up to temperature in 3rd and O/D.
     
  2. Philip1

    Philip1 Supporting Member Supporting Member

    Posts:
    398
    Likes Received:
    329
    Joined:
    Apr 1, 2019
    Location:
    Northeastern Nevada
    I would check your fuel pressure and see if either the lift pump, overflow valve or air intrusion causing issues. My dad had a similar issue with the lack of power and it was a bad overflow and a loose hose clamp going into the lift pump.
     
  3. u2slow

    u2slow bilge rat

    Posts:
    1,065
    Likes Received:
    317
    Joined:
    May 8, 2007
    Location:
    PNW
    Also check the fuel supply solenoid on the IP, and it's wire connection.
     
    idiTravelAll likes this.
  4. idiTravelAll

    idiTravelAll Full Access Member

    Posts:
    332
    Likes Received:
    133
    Joined:
    Sep 2, 2017
    Location:
    Gilbert, AZ
    Yep mines been acting up, relay for fuel shutoff solenoid.. been tying it up and untying to shutdown.. tried to install a manual cable (planned to but wanted to wait until after I make a new dash) my darn FSS 8mm bolts do not want to move and its helluva tight spot after the conversion.

    EDIT: if you remove the FSS relay and stick a paper clip in the 2 prongs you should hear a solid click from your FSS.. be sure to remove paperclip ASAP or its going to change colors in your hands (bright orange)
     
  5. irhunter

    irhunter Registered User

    Posts:
    14
    Likes Received:
    3
    Joined:
    May 22, 2020
    Location:
    Maine
    I agree..."randomly shut off" sounds like an intermittent FSS issue. I have, on occasion, wired in a temporary indicator light. I pick up the power right at the FSS and have the light in the cab. The light is wired to glow whenever +12v is present at the FSS.

    Roy
     
    idiTravelAll likes this.

Share This Page