Won't Start FI Code c41 - Fuel Pump/Relay

Discussion in 'General Bike Related Topics' started by ajblbv, Apr 10, 2010.

  1. ajblbv

    ajblbv Donating Member

    Okay, synced the throttle bodies today as per Jinksters write up. Put it all back together. An hour later go to go for a ride, using the choke (fast idle) it ran for 30 seconds, then died. Threw the code c41. Fuel pump/relay failure. Checked relay, it is fine....checked for continuity and that it triggers. Checked pump, fires fine....if giving the pump power and cranking the bike runs. Went to check all the vacuum. Turns out I must have disconnected the vacuum line going onto the pressure regulator on the pump. As seen in the second pic. It goes into a T fitting that shoots back to the middle vacuum line in the first pic. The other side of the T goes to the IAP sensor, which also tests as within expected voltage.

    So I am stumped, I believe that since the vacuum does not exist, the pump will not prime, but I do not know how to get it to try to recreate the vacuum. I tried running it for 5 seconds with constant power to the pump.

    I also tried a few other variations of the above tests. I am convinced the pump works, the relay works, and hoping that the disconnected pressure regulator caused the initial code. Any and all input is welcome, I am currently stumped.

    TIA :please:

    Attached Files:

    • fi.jpg
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    • fi2.jpg
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  2. ajblbv

    ajblbv Donating Member

    also note it is a 1999, so external fuel pump
  3. ajblbv

    ajblbv Donating Member

    I went to start it this morning, hoping that 12 hours of a disconnected battery would clear the code. No such luck.

    Any thoughts please? ???
  4. Johnnycheese

    Johnnycheese Registered

    as long as you plug the hose it will not throw a code and it will run
  5. ajblbv

    ajblbv Donating Member

    plug it? Right now I have it hooked up to the pump and it won't

    the pump will not prime, only way I get it to run is to jump it with a constant power....but do not want to do that for too long, as I question if it will shut off at the right pressure....

    or should I do that and the pressure regulator save me?
  6. Poppy

    Poppy Donating Member

    Hmmm, I think I would start from the beginning and check each step. Make sure that I did each one and did not skip one. Even try reversing the steps. Probably something simple....well hoping so! Good luck!
  7. Poppy

    Poppy Donating Member

  8. ajblbv

    ajblbv Donating Member

    Thanks for the post poppy.....unfortunately already tried swapping the 10 A fuse out with no luck.
  9. Blanca BusaLess

    Blanca BusaLess Suffers from PBSD Donating Member

    1st question: Did bike run fine before you worked on it ?
    if yes I agree with Poppy. Something simple and self inflicted.

    If it was stumblin and bumblin and that made you want to work on it then I dont know, sorry.

    Hoses are usually there for a reason. Why would you want to plug it ?

    Does it run fine now and you just cant erase code on dash ?
  10. ajblbv

    ajblbv Donating Member

    Was running fine. I agree self inflicted just trying to figure out what I did. Bike will only run now if pump has constant power, which I am not sure if that is a good thing. Will the pressure regulator turn the pump off once proper pressure is achieved? If so I don't mind doing that, otherwise I am worried about running constant injectors into the system.
  11. Blanca BusaLess

    Blanca BusaLess Suffers from PBSD Donating Member

  12. djsin

    djsin Lily's Daddy Registered

    fuel pumps normally do run all the time...whatever gas isnt being used re-circulates and goes back into the tank running the fuel pump all the time will not effect the injectors at all they are controlled by the ecu, which will turn them on/off the pressure being regulated into the fuel rail, only insures that the injectors have the right amount of pressure when they fire, not low or high...
  13. ajblbv

    ajblbv Donating Member

    Will giving it constant power at the relay point bypass the ecu signals or would I be fine to do that? The pump only runs to maintain pressure on the 99/00 to my understanding. And when priming initially it does shut off.
  14. ajblbv

    ajblbv Donating Member

  15. djsin

    djsin Lily's Daddy Registered

    although it does shut off initially im pretty sure once its actually started and runing the fuel pump turns back on and stays on

    i think it primes then shuts off so all the battery power can be directed to the starter
  16. ajblbv

    ajblbv Donating Member

    Just to update, replaced ECU and clutch switch and bike started right up. One scenario is I fried the ECU myself while trying to bypass relay. This would not explain the code. Other scenario is something else fried ECU, which threw the code, and then new one fixed it. Clutch switch possibly unrelated.

    Just wanted to update for the archives.
  17. BigBSBusa

    BigBSBusa Comin' back stronger than ever! Donating Member

    Glad you got it fixed.
  18. frustratedbusaowner

    frustratedbusaowner Registered

    I have a 99 busa with the same problem. C 41 code. replaced relay and ecu but it still will not run unless the relay is jump for constant power. And when it does run it will sputter and burn rich at higher rpm. Completely stumped. ANY help is welcome.
  19. IG.

    IG. Registered

    Way to bring the old post...

    Anyway, it would be helpful if you gave a bit of a history. Was any work done on a bike? Or it just happened?

    Any chance you got a bad connection inside the connector? Disconnect, look inside with a flashlight.

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