EFI Backfire into intake - twin cam 88B

Discussion in 'Engine, Fuel and Exhaust' started by rvgriff, Jul 28, 2009.

  1. rvgriff

    rvgriff Member

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    Been reading on here for a few days and decided to join in. Fantastic site and look forward to sharing a few tip/tricks/stories with you all. In order for me to do so I need to get my 02 Deuce up and running first...

    Here is my issue and what I have done so far:

    Important note is that this is a Deuce made from 2 parts bikes and a custom frame. The 88B and Baker 6-speed are brand spankin new. The wiring harness/ECU/TSSM and all sensors are from the same running bike.
    As the title states once it starts up it immediatly begins to run very rough and backfire through the intake. Will do this at any RPM so long as the throttle position is not changed. When I pained the tank I replaced all of the internals, pump, regulator, filter before sealing it up. I have since replaced the seals from the throttle body to the jugs as it appears that I have an intake leak according to some searching on here and elsewhere. No change... Tried spraying carb clean around intake area but I am not getting an RPM change anywhere. New plugs/wires..no change. Cleared the codes and let her run for about 10 min by slightly twisting the throttle to keep it running. No DTC codes being thrown at all now. 88B is stock with a set of V&H pipes and screaming Eagle intake w/ K&N filter.

    Here is a pic of her before I cleaned up the wiring and such. Please help me get her on the road where she belongs! Thanks in advance for any ideas/advice you may have:rider
     

    Attached Files:

    Last edited: Jul 28, 2009
  2. glider

    glider Veteran Member

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    I would start with a compression test to see if both cylinders are up to the task being it's popping back from the intake.
     
  3. rvgriff

    rvgriff Member

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    Also I have verified that voltage stays between 13 - 15V when running so I'm pretty sure it is fuel related not voltage.
     
  4. glider

    glider Veteran Member

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    You could drain the tank and clean it out and start over again with fresh fuel if you feel it's fuel related.
     
  5. rvgriff

    rvgriff Member

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    front is 98psi
    rear is 100psi
     
  6. glider

    glider Veteran Member

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    Doesn't sound like you held the throttle open for that compression test, kind of low readings.
     
  7. rvgriff

    rvgriff Member

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    did this as well with premium fuel as well as injector cleaner...no change

    Thanks for helping me out!

    manual states that anythign > 90psi is "normal"

    This may be part of the issue if ~100psi is not acceptable.
     
    Last edited by a moderator: Jul 28, 2009
  8. glider

    glider Veteran Member

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    90 is far from normal in my book, it's LOW!
     
  9. rvgriff

    rvgriff Member

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    That 100psi was not with a WOT so I'll go test it in a bit with a WOT.
     
  10. glider

    glider Veteran Member

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    I think you will see a difference in the readings.