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Fuel Pump Problem- Mechanical Vs Electric?

Discussion in 'Jeepster Commando and Commando Tech' started by WillyBoy12369, May 10, 2023.

  1. May 10, 2023
    WillyBoy12369

    WillyBoy12369 New Member

    Montana
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    I have recently bought a 1973 Jeep Commando with a v6 4.2l 258 - have a 1 barrel YF Carter - what is the correct fuel pump part number? Should I buy a carter?? I have tried a mechanical fuel pump from NAPA and the PSI is to high and blowing by the needle. Should I switch it to electric fuel pump?? Should I put an inline fuel pressure regulator?? Don’t know what to do and would appreciate some advice what I should do.

    Some Overview / Background why I replaced it is when I bought it the diagram was bad I assume and there was gas in the oil - pumped hard but didn’t want to risk it or waste money on changing oil over and over. After i replaced it it was dumping out of the metering rod area on the crater (which it looked like it was previously) so I rebuilt the carb and replaced fuel pump and it increased fuel dumping out of the metering rod area and barely run cause of flooding, I installed a fuel filter with a return and it was alottt of fuel coming out of the return line and barely runs it’s just been flooded
     
  2. May 10, 2023
    colojeepguy

    colojeepguy Colorado Springs

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    It's unusual for a mechanical fuel pump to put out enough pressure to overpower the needle & seat. If that's what's going on I would take it back to the parts store and get them to warranty it.
     
  3. May 10, 2023
    WillyBoy12369

    WillyBoy12369 New Member

    Montana
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    Already did. The reviews of it on other auto stores had the same exact issues. Delphi MF009 pump. Some websites even says it’s the incorrect part, some day it fits
     
  4. May 10, 2023
    colojeepguy

    colojeepguy Colorado Springs

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    Hmm, I think I'd try a different brand. You could install a pressure regulator but it shouldn't be needed. I mean, this is just an old 6 cyl with a 1 bbl carb...shouldn't be too complicated!
    This is all assuming your carb is functioning as it should. Have you actually tested the pressure?
     
  5. May 10, 2023
    PeteL

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

    Hills of NH
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    This.
     
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  6. May 10, 2023
    WillyBoy12369

    WillyBoy12369 New Member

    Montana
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    I agree and I do believe it’s functioning properly because I rebuilt the Carb, then blamed myself and bought a new float - and triple checked adjustments. I messed up and went against my cardinal rule, don’t replace multiple new parts at the same time while fixing an issue (even though I had a valid reason). No I haven’t pressure tested it yet, haven’t had the tools for it - but yes I should. Attached is a photo of the bucket after installing the return line filter and that is from only it turning over running than dying from being flooded. Not only there it was also dumping out of the carb down that not sealed metering rod I was talking about. Which to me is a obscene amount of fuel for cranking start and die for the return line to be pumping
     
    Last edited: May 11, 2023
  7. May 10, 2023
    WillyBoy12369

    WillyBoy12369 New Member

    Montana
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  8. May 10, 2023
    WillyBoy12369

    WillyBoy12369 New Member

    Montana
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    How do I upload pictures? File too big so I added to Dropbox and added a link to a pic and they didn’t work got flagged and moderated.
     
  9. May 10, 2023
    WillyBoy12369

    WillyBoy12369 New Member

    Montana
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  10. May 10, 2023
    colojeepguy

    colojeepguy Colorado Springs

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    Your link works.
    To upload pictures directly they have to be under 1MB in size.
     
  11. May 10, 2023
    vtxtasy

    vtxtasy oldbee 2024 Sponsor 2023 Sponsor

    Tucson, AZ
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    You can rent/borrow a fuel pressure test gauge from O'reilly auto.
     
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