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Carburetor, Fuel Pump, Timing, Or Other

Discussion in 'Early CJ5 and CJ6 Tech' started by johnsotd, Jan 13, 2017.

  1. johnsotd

    johnsotd Member

    62 cj5 f 134 new build. Went for a short drive yesterday to put a couple of miles on my Jeep and to get some gas. I went through the neighborhood because I don't yet have a title.
    The motor ran great on open stretches but went dead at every stop finally not starting for an extended period. After much effort it restarted and got me home where it died while idling. I have the fuel pump with the glass bowl and vacuum pump which is plugged off. I can see gas moving at idle and the bowl is full at speed. I have cleaned the carburetor twice. Could this be a timing issue? I have never found the timing mark? (I know where it is supposed to be).
    As usual, I appreciate your help.
     
  2. jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Maybe points in the distributor? Or timing.
    Try to change all the fuel and fuel filter.
    My timing mark on the pulley was very faint. I had to lay underneath it with my surfire light to se the notch. Once i found it, i painted it white with the wifes nail polish.
     
  3. PeteL

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

    Could be timing/points. But also sounds a lot like flooding/over-rich mix. Takes it at open throttle. but too much gas at idle - and that would indeed make it hard to restart.

    BUT you should always have your points and timing set to spec as the basic beginning of ANY tune-up or diagnosis. Takes maybe 15 minutes. Otherwise you'll be going in circles fixing things that ain't broke, which will then mess up what was good to begin with.

    How to Tune Up Your Car

    This is basic FSM Chapter One stuff, but apparently that knowledge died with the dinosaurs.
     
    Last edited: Jan 13, 2017
  4. johnsotd

    johnsotd Member

    I have rebuilt the carb at least twice with no improvement. I have looked until my eyes hurt for the hidden timing mark but try once again.
    Thanks for the advice.
     
  5. ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    After having a faulty condenser recently, that is the first place I now look for mystery problems. It can really show up as odd symptoms. They're cheap and easy to swap out, just to rule out if nothing else.
     
  6. Daryl

    Daryl Sponsor

    Could also be a vacuum leak. Check that the carb is tight on a good gasket.
     
  7. Glenn

    Glenn Kinda grumpy old man Staff Member

    Yep, a vacuum leak can definitely mess with you. I think I remember someone else having that same problem and found out the carb was loose.
     
  8. johnsotd

    johnsotd Member

    I have been working on this off and on since my last post. I think timing is OK Found TDC. I checked for a vacuum leak with brake cleaner the last time it ran and found no issues.
    Today I took the top of the carburetor off to check the float and it looks like it is set right,....BUT..... the bowl is bone dry. What could cause this????
    Thanks
     
  9. PeteL

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

    I'm surprised there would not be some residual gas in the bowl. Is it possible the accelerator pump diaphragm is leaking, despite your two carb "cleanings?" That could explain it dying at idle, also.

    Otherwise, I guess it is time to check the output from your fuel pump, although you said you have fuel reaching the pump bowl.

    Disconnect the fuel line at the carb, check the pressure with the line capped while cranking - should be 3psi or slightly more.
    Then also check output volume. With no restriction, the line should flow the equivalent of one quart per minute "at idle speed" per FSM.
     
  10. johnsotd

    johnsotd Member

    The fuel pump is pumping fuel although I don't know the volume or pressure but it looks like it should be adequate. I did have an accelerator pump diaphragm on another build that was ruined by ethanol gas. I will check this one carefully.
    Thank you
     
  11. garage gnome

    garage gnome ECJ5 welder

  12. scoutpilot

    scoutpilot Member

    Who rebuilt it? Has this motor been properly broken in? “It looks ok” doesn’t mean anything. Got some numbers?
     
  13. ETZFAM

    ETZFAM FLATIES & ROUND FENDERS, SOME EVEN RUN

    As mentioned before, those fuel pumps with the glass bowls, the gaskets for them are not what they use to be, a small leak there and intermittent problems?

    Rick
     
  14. johnsotd

    johnsotd Member

    I don't know how to check the fuel pump other than to see if it is pumping.
    Can the fuel pump siphon fuel back out of the carb. when the motor is off.
    I rebuilt this carb. and payed close attention to the directions but maybe I missed something.
    I'll do it again.
     
  15. garage gnome

    garage gnome ECJ5 welder

    Thats exactly what my jeep was doing. I put a good carter pump from rock auto in and problem went away.