fuel pump wont suck

Discussion in 'PSI Superchargers Tech Questions' started by pat Iley, Jul 19, 2019.

  1. kosky racing

    kosky racing Comp Eliminator

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    lubed pump will suck fuel up - good pump the same- like I said before pumps are not able to suck air- gas does not matter-front end raised will help the pump but once it looses prime your back to a dry pump Call any pump mfg. ask them if there pump can suck air.some vane pumps will suck up fuel
     
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  2. Ron Meyer

    Ron Meyer New Member

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    Check the drive to the pump. It may be turning without load, but drive may have rounded the corners or something similar and won't turn the pump. Could be a shaft has broken, too. I see that you have checked to see that it was turning, but was it actually turning the pump?
     
    #22
  3. jd956

    jd956 New Member

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    I'm having just about the same issue, we also tried 2 different pumps. So what would you say fixed your issue? Are you thinking maybe just switching out the O-rings to every fitting that required one? On our motor It will idle just fine using the priming pump that we have plumbed right into to the hat distribution block, and it will run for about a whole minute or until the priming circuit runs out of fuel, BUT the main pump running off the cam still won't pick up the fuel. Yes the slot on the pump cover is on the correct spot, which is to the driver side since it is cam driven. Also we tried both pumps with drills on the hex and the shut the fuel right out of the pumps with ease. One of the many tests that we did was remove the feed hose from the shut off valve outlet to the k-valve. Then we cranked the motor over for several seconds to see what the fuel would do at the shutoff valve outlet fitting and all it would do was just bounce up and down, it would not even shower out of the fitting this was done with the fuel tank cap removed also for venting purposes. We run a -16 hose from the tank to pump, tank is higher than the pump and no filter is used between tank and pump. I was starting the think that maybe the fuel is some how bypassing the shutoff valve and coming out on the return side but we disconnected the return hose also and no fuel comes out at all while cranking.
     
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  4. kosky racing

    kosky racing Comp Eliminator

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  5. kosky racing

    kosky racing Comp Eliminator

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    Do you have a 4-Way shutoff on this system?
     
    #25
  6. Bjs344

    Bjs344 Member

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    I’ve had an interesting deal happen on our injected car. The last couple times I had the fuel system cracked for some reason, the pump “air locked”

    It’s a belt drive pump mounted well below fuel level.

    I’ve had the car running on a primer for up to a full minute before the mechanical (enderle 110) would pump. I eventually found that if I cracked the outlet of the enderle while the car was running on the primer that it would start pumping sooner.

    Never had this happen on our blower car. Main difference is the blower car has a 3 way right on the pump outlet but the injected car has some plumbing above the pump before it can return/bypass.
     
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  7. Dave Koehler

    Dave Koehler Member

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    New starter may help but unlikely.
    Yeah, the 20 needs some rpm.
    Actually mfi and mags in general love rpm.
    Consider 24V to the starter armature. 12v to the solenoid
    Changing to a smaller flexplate diameter will also speed up the cranking rpm.
     
    #27
  8. secondwindracing

    secondwindracing top alcohol

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    Take pump off and see if it pumps..if not you put the pump together wrong if it does pump check your tank vent or just take cap off of tank and fire it up..make life simple check things in the order it works..that being said check the pump first
     
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  9. jd956

    jd956 New Member

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    No, I don't have a 4 way. I have a 3 way shutoff valve.
     
    #29
  10. jd956

    jd956 New Member

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    Pump was taken off and inlet was pump in a pan of clean mineral spirits, then pump was turned counter clock wise with a drill slowly and at high speed. When spinning slowly the mineral spirits was fountaining out through the outlet, and at high speed the mineral spirits shot out across the shop. we have removed the tank cap while trying to start but no luck.
     
    #30
  11. jd956

    jd956 New Member

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    Also we have removed the main outlet hose going to the inlet of the K-valve from the shutoff valve and fuel it at the outlet of the shutoff valve. then we crank the engine over with the starter and watched the fuel just pulsate at the shutoff valve outlet fitting. You can see it go up and down the fitting, but it never showers out of the fitting. Was thinking air is in the pump gears .
     
    #31
  12. kosky racing

    kosky racing Comp Eliminator

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    What brand of pump? make model size?
     
    #32
  13. jd956

    jd956 New Member

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    110-Enderle
     
    #33
  14. kosky racing

    kosky racing Comp Eliminator

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    from what you describe the pump is in the wrong rotation
     
    #34
  15. jd956

    jd956 New Member

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    The fuel pump cover tab is pointing to the driver side of the engine. It is a cam driven pump and the motor spins CW. However in order to test it with a drill you have to spin it CCW, since you are acting like the cam and the pump is in front of you.
     
    #35
  16. secondwindracing

    secondwindracing top alcohol

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    facing the motor your pump will be turning clockwise..... so if you use a drill I has to be running in reverse to be acting like it is running in your motor
     
    #36
  17. secondwindracing

    secondwindracing top alcohol

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    I think you have your pump put together wrong
     
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  18. Mike Kern

    Mike Kern Member

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    I'm not going to comment on what the issue might be because there are just too many possibilities and I can't see through an ethernet wire. What I will say is this...even on a big show, big pump car, every time I start the car after an "empty" fuel system, I prime the pump and system before we start the car. The more return and bypass systems that you have, the more the chance of an air lock or rough running until the system is full. To prime the system we remove the pump outlet fuel line at the barrel valve and dump it to a fuel jug. We then open the fuel shut-off and crank the engine until we get a good flow of fuel through the line. It may help to lower the rear of the car to garner a decent gravity feed to the pump inlet. This should ensure the system is full prior to attempting to start the car. If you can't get a good flow, you need to start looking for the problem. Even with priming the pump it takes a good 30 seconds of running to move the air out of the fuel management system. With alcohol cars/low idle volumes it may be harder to keep it running so this may help.
     
    #38
  19. MKR-588

    MKR-588 Member

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    Did you eventually work out the issue you had with the pump not lifting / pushing the fuel ?
     
    #39
  20. J.M.J pegasus

    J.M.J pegasus New Member

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    Had a similar problem, ended up being the roll over safety vent on the fuel cell stuck ,not allowing to vent ,replaced the vent and i Welded in a another vent addition to the existing vent.
     
    #40

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