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62 CJ5 Mechanical Fuel Pump Issue

Discussion in 'Early CJ5 and CJ6 Tech' started by sidaemon, Jul 19, 2015.

  1. sidaemon

    sidaemon New Member

    I just put in a new fuel pump, and i have no experience with mechanical fuel pumps. I can get the rig started by priming the carb directly with fuel, but even with the rig running i'm not seeing fuel fill up the glass bowl on the new fuel pump? First, is that normal? I would assume the entire point of having a glass bowl would be so you could see the fuel... Second, the instant I let off the gas the rig dies...

    Am i missing something with having to prime the system, or just keep running the rig until the system primes up?

    Thanks!
     
    sidaemon, Jul 19, 2015
    #1
  2. Simi Valley CJ-5

    Simi Valley CJ-5 Chief Cook and Bottle Washer

    Which engine are you running?
     
    Simi Valley CJ-5, Jul 20, 2015
    #2
  3. sidaemon

    sidaemon New Member

    The 134 F-Head. Stock pretty much everything as far as I can tell. The mechanical pump is an Omix Ada, the type with the glass bowl on the top. I'm also using a clear grass style fuel filter with the ceramic filter. Neither is showing any fuel working through the system.
     
    sidaemon, Jul 20, 2015
    #3
  4. uncamonkey

    uncamonkey Member

    Stupid reply, sorry.
     
    Last edited: Jul 20, 2015
    uncamonkey, Jul 20, 2015
    #4
  5. uncamonkey

    uncamonkey Member

    Stupid reply, sorry. I can't delete this mess...
     
    Last edited: Jul 20, 2015
    uncamonkey, Jul 20, 2015
    #5
  6. scoutpilot

    scoutpilot Member

    If your motor is running well, don't worry about how much fuel is in either bowl. Some air is required in the pump for back pressure against the intake check valve. As long as the brass screen in the pump is covered with fuel, and some fuel shows in the filter, your golden.
     
    scoutpilot, Jul 20, 2015
    #6
  7. Glenn

    Glenn Kinda grumpy old man Staff Member

    Glenn, Jul 20, 2015
    #7
  8. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    The gasket under the glass bowl must be good, and seal well, for the pump to operate. (FWIW - Omix-aida parts are not especially well regarded around here.)

    BUT...

    You seem to be able to keep the engine running at higher rpm, but it won't idle? That must mean the pump is primed and working. Sounds more like a Carb issue.
     
    PeteL, Jul 20, 2015
    #8
  9. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    The fuel will only come up to the level of the screen until you bounce around enough to blow the air bubble above it out the line to the carb. If it keeps running after starting by holding the throttle open you're good with the pump, if it dies when you let the throttle off you probably have some kind of a carb problem, or maybe electrical, or maybe a vacuum leak, or maybe timing, or maybe...

    H.
     
    Howard Eisenhauer, Jul 20, 2015
    #9
  10. Yooper John

    Yooper John Member

    If you have your original pump, rebuild and reinstall it.
     
    Yooper John, Jul 21, 2015
    #10