Lean on decel????

Discussion in 'PSI Superchargers Tech Questions' started by Motorworx127, Oct 8, 2022.

  1. Motorworx127

    Motorworx127 Member

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    hi guys runnung blown BBC 565 folwer Fowler F11 11.25 static on m1 about 28-30 degrees of timing
    Latley after I lift on a pass the truck is going lean 7.0-8.0 AFR Not during pull only after i lift. It pops and bangs and sometimes shuts down on coastdown Ive checked all fuel lines externally and internally and all poppets seem ok and free When it shuts down its sounds just like it does when you kill the engine by fuel revs up and cuts off Any ideas? im thinking my pump saver is hanging open but took it apart cleaned and lubed seemed fine
    I run a single high speed also and looked fine too
    I maintain my fuel system after everyouting with some gas and a touch of 2 stroke oil has worked fine since 2018
    any help or ideas would be appreciated
    Oh after i restart the engine all seems fine
     
    #1
    Last edited: Oct 8, 2022
    Motorworx127, Oct 8, 2022
  2. kosky racing

    kosky racing Comp Eliminator

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    Run the pump saver to the back of the b.v. -not the tank
     
    #2
    kosky racing, Oct 8, 2022
    Motorworx127 likes this.
  3. Motorworx127

    Motorworx127 Member

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    Thanks i was thinking it was pump saver .. just cant figure why just started doing this after 3 years
     
    #3
    Motorworx127, Oct 8, 2022
  4. Nitro Madness

    Nitro Madness Super Comp

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    Not sure feeding the pump saver to the engine is a great idea....i have heard of several engines hydraulicing and breaking rods with pump saver routed to the fuel block behind the blower...
    Could the lean condition be fuel sloshing forward in the fuel tank? Have you made any changes to the fuel tank or fuel lines lately?
     
    #4
    Nitro Madness, Oct 8, 2022
  5. kosky racing

    kosky racing Comp Eliminator

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    If your running nitro
     
    #5
    kosky racing, Oct 8, 2022
  6. Mike Canter

    Mike Canter Top Dragster
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    Is it a clutch or a converter car? Are you putting it in neutral or declutching it at the finish line? Yes it is going to run lean if you let up on the throttle because you are closing the barrel valve and therefore shutting of all the fuel and the engine is still spinning. The pump saver is not going to help because your fuel pressure is not that high. How are you measuring AFR?
     
    #6
    Mike Canter, Oct 8, 2022
  7. kosky racing

    kosky racing Comp Eliminator

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    If the engine is still spinning and the throttle is closed the pump saver port opens
     
    #7
    kosky racing, Oct 9, 2022
  8. Mike Canter

    Mike Canter Top Dragster
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    Depends on where the check valve is set and the pump pressure
     
    #8
    Mike Canter, Oct 9, 2022
  9. kosky racing

    kosky racing Comp Eliminator

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    True but the pressure spikes when throttle is closed and opens the pump saver
     
    #9
    kosky racing, Oct 9, 2022
  10. Mike Canter

    Mike Canter Top Dragster
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    Only during that pressure spike. I never even ran a pump saver. Had it blocked of and never had a problem and never ran lean that I cared about since you are not making power because the ignition is shut off.
     
    #10
    Mike Canter, Oct 9, 2022
  11. kosky racing

    kosky racing Comp Eliminator

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    i have had pumps brake shaft when we ran with no pump saver
     
    #11
    kosky racing, Oct 9, 2022
  12. Mike Canter

    Mike Canter Top Dragster
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    Never had it happen with todays new pumps. I know Mike Janis also runs without a pump saver on all his engines.
     
    #12
    Mike Canter, Oct 9, 2022
  13. kosky racing

    kosky racing Comp Eliminator

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    Mike do you know weather its a high pressure system or low
     
    #13
    kosky racing, Oct 9, 2022
  14. Mike Canter

    Mike Canter Top Dragster
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    I normally set the system up so I have 125-135 lbs at 8000 in first gear at the output of the pump. That usually puts max pressure in the low to middle 200’s. So is that a low pressure or high pressure system in your view.
     
    #14
    Last edited: Oct 10, 2022
    Mike Canter, Oct 10, 2022
  15. Templar Motorsports

    Templar Motorsports Member

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    Could your fuel be moving forward away from the pickup in the tank at shut down? That would cause a lean condition for sure.

    I could be wrong but doesn't the pump sizer line feed back to the suction side of the fuel pump?
     
    #15
    Templar Motorsports, Oct 10, 2022
  16. Motorworx127

    Motorworx127 Member

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    Here is some more information Enderle 1100 16.9 GPM on M1 Dual wide bands in 1 and 2 (problem holes) adjusting for 3.4 to 3.8 AFR I adjust remaing port nozzels from the burn on 1 and 2 I try keep it a little fat helps me manage the tire and keeps her safe We run this in the No Prep Scene so we do loose the tire once and a while. so if fat tends to save head gasket it we zip tire at 150 Fuel pressure is 180-200 psi end of first gear We have ran same set up since 2018 and this issue has only developed in last 3 outings attached are 2 grid files that show what is going on The first is a run i pedalled and it got real ugly after i lifted Popping and banging and shut down the second was a clean 4.80 pass and still went lean but not as bad
     

    Attached Files:

    #16
    Motorworx127, Oct 11, 2022
  17. Motorworx127

    Motorworx127 Member

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    sorry above should read 200-215 psi fuel pressure during the run only have the guage
     
    #17
    Motorworx127, Oct 11, 2022
  18. Mike Canter

    Mike Canter Top Dragster
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    Again why do you care what is happening after the finish line. You have let up so the fuel is shut off and your ignition should be off
     
    #18
    Mike Canter, Oct 11, 2022
  19. Templar Motorsports

    Templar Motorsports Member

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    Any new info on the issue you have been having? Did you get your problem solved?
     
    #19
    Templar Motorsports, Oct 25, 2022

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