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have a fuel system problem, need help

Discussion in 'Early CJ5 and CJ6 Tech' started by Cazador, Nov 4, 2004.

  1. Cazador

    Cazador New Member

    The fuel drains out of the fuel line between the fuel pump and the carb on my '65 CJ-5 (with F-Head eng). The Jeep runs great when it is runnning, but after it is shut down and sits for a few minutes, it won't start until fuel is pumped all the way back up to the carb from the fuel pump. I have a clear plastic fuel filter located between the fuel pump and the carb, so I can see there is no fuel in the filter after the Jeep sits for a little while....where is the fuel going, back into the tank or down into the crankcase?
    Is this problem due to a faulty fuel pump or is there something else going on here?
    All help appreciated!
     
  2. lynn

    lynn Time machine / Early CJ5 HR Rep Staff Member

    I'd throw a few bux at a new fuel pump and see if that corrects the problem. Might have a diaphragm with a small leak.
    Does your motor oil smell strong of raw fuel?
     
  3. sparky

    sparky Sandgroper Staff Member Founder

    I'm with Lynn, classic symptoms of a bad diaphram in the fuel pump.

    Drains into the crankcase...
     
  4. TheBeav1955

    TheBeav1955 Member

    Had the same issue on my 72. Changed the pump problem gone.
     
  5. dauntless_powered

    dauntless_powered SUB COB 2024 Sponsor

    you mean this is not normal :oops:

    i have to watch again, but i think mine is doing the same thing this whole time :oops:
     
  6. Cazador

    Cazador New Member

    I was afraid this is what you guys would tell me. I put a new fuel pump on about 6 months ago, so I guess I have to go buy another new one....bummer. Is there an electric pump that might be a better choice than the stock mechanical pump...or would putting on an electric pump just be more time consuming without providing any improved reliability?
     
  7. dauntless_powered

    dauntless_powered SUB COB 2024 Sponsor

    the po installed and elec fuel pump in mine and i have had no probs with it, i would have installed one if he didnt
     
  8. Boyink

    Boyink Super Moderator Staff Member

    I've run electric fuel pumps for years. Just spend the coin to get a good one, and not the little "barrel style" that the Autozones and their ilk sell.

    Oh, if you go that route you might also want to run a pressure regulator as well so the pump doesn't overwhelm the carb.
     
  9. jeepdaddy2000

    jeepdaddy2000 Active Member

    Be sure that you install the filter before the pump. This will help eliminate debris from entering the pump causing diaphram seal failure.
     
  10. Cazador

    Cazador New Member

    Anyone have any recommendations on make/model of electric fuel pump? Where do you recommend mounting it and is there a "block off plate" or something to take the place of the original fuel pump?
    '65 CJ-5 with F-head engine and Solex carb.
     
  11. Boyink

    Boyink Super Moderator Staff Member

    I mounted one under the body in the drivers seat area, where the rear floor and front floors meet and there's that 4-5" difference. The pump I bought said it could push or pull.

    Sorry, no hints on brand...that was a good number of years ago.
     
  12. Cazador

    Cazador New Member

    Thanks to y'all for the advice and diagnosis....I believe I will go see if I can find a replacement stock type fuel pump today and go that direction one more time....then if the next new one fails quickly, I'll investigate electric pumps. I might have just had bad luck with this particular pump....my last one lasted for more than 10 years before I had problems.
     
  13. Russell

    Russell New Member

    Just remember that with the electric pump the fuel keeps coming even when the engine is not running. A friend of mine burned up his car with an electric pump.

    He did not realize what killed the engine. He left the key on while it drifed to a stop, then as he cranked it. POOF!! Burned out completely.
     
  14. Mudweiserjeep

    Mudweiserjeep JEEP: Bouncy and Fun

    When you install a electric pump what do you do with the old pump? I mean you remove it but do you make a cover that goes in the place of the mechanical pump?
     
  15. Boyink

    Boyink Super Moderator Staff Member

    I just left the stock pump, plumbed to itself. Never tried it but hoped it could be an emergency backup...

    There are blockoff plates avail, or you can make one out of sheetmetal.

    Mine had a switch to the dash.

    Actually I think SSDutch has some kind of safety measure...oil pressure switch tied it maybe?
     
  16. Ledge

    Ledge Member

    It's a real good idea to do with an electric pump. Control the pump with a relay switched by an oil pressure switch. If you want to shorten crank times a bit, also have the pump activated whenever the key is in the cranking position.
     
  17. Mudweiserjeep

    Mudweiserjeep JEEP: Bouncy and Fun

    Having a back-up, not a bad idea Mike. Never hurts to have a plan "B".

    I would think a safety feature would be very important to consider.
     
  18. Boyink

    Boyink Super Moderator Staff Member

    PO also added a push-button switch on the pump...if I understand his intent/explaination, I push the button until the pump gets quiet, then fire up the Jeep.
     
  19. Cazador

    Cazador New Member

    No luck finding a stock fuel pump in town, had to have the parts guy order it from Sacto for me...just like last time.
    This time, I ordered the single diaphram pump instead of the double diaphram type because I have done away with the vacuum wipers and no longer have need for a double diaphram model. The single diaphram model is about 2/3 the price of the double model, too.
    New pump should arrive early next week and the price is around $40-45.