R1150 Quit Running, Fuel Pump Won't Stop. Thoughts?

Discussion in 'GS Boxers' started by Eric Marsh, Feb 13, 2020.

  1. Eric Marsh

    Eric Marsh Adventurer

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    I finished prepping my r1150 GS for the next season a couple days ago. Changed all the fluids, filters, plugs, etc. While I was working on the bike I replaced the injectors with a matched set of 1200 injectors and installed a Gemi chip.

    Everything was fine for a couple hundred kilometers and then running down the road the engine just stopped running. I was going down hill and had some speed so I tried turning the ignition off and on then bump starting it. No luck. I tried the starter motor and the engine came back to life. I had fueled up perhaps seven km before.

    A couple kilometers later it died again and this time it wouldn't restart. When I was trying to start the bike I noticed that the fuel pump kept running. So I made a few phone calls and twenty minutes later decided to give it another try. This time the pump ran for a second and then stopped and the bike started and ran fine. Feeling fortunate I headed for home and made it with no more problems.

    I don't want this to happen again.

    So I'm trying to figure out what caused this problem. I've got a few ideas.

    Something to do with the Gemi chip.

    Somehow a check valve got stuck open and it couldn't build pressure. But why would it get unstuck with the bike just sitting?

    One of the injectors stuck open and bled off the pressure. I think this is extremely unlikely.

    A bad fuel pressure sensor. I'm thinking that this might be a good guess.

    Crud in the gas. But the filter should have caught that.

    Has anyone seen anything like this before? Any suggestions or thoughts on what I should do next?

    Thanks
    #1
  2. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    My guess is you have water in your gas and it got into the fuel filter, temporarily blocking it. Time for a filter change.
    #2
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  3. Eric Marsh

    Eric Marsh Adventurer

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    Not a bad idea in any case.
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  4. mouthfulloflake

    mouthfulloflake Not afraid

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    on initial start up, that fuel pump runs for a second and then goes off.
    That is built into the motronic chip, and not a pressure related turn off.

    if it kept on running I would suspect some sort of glitch in the EPROM software that is braining the motronic.
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  5. Eric Marsh

    Eric Marsh Adventurer

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    John Gemi said that it's a possibility and that he will send me another chip just in case. I think I'll replace the fuel filter too, just on principle.
    #5
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  6. Muscongus

    Muscongus Been here awhile

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    Just a thought, is it possible for the HES to fail such that the fuel pump is always triggered on?
    I know from an R1100r that I owned that failure of the HES doesn't always manifest in the most common way.
    (that bike started everytime, but had a miss. When I eventually checked the HES all the insulation inside the sheathing was completely melted, the wires all
    surrounded by crystalized melted goo. It was amazing it ran)
    I know that it's best to assume that problems are related to whatever was last done to the bike, but maybe this is worth considering anyway.
    #6
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  7. mouthfulloflake

    mouthfulloflake Not afraid

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    I would think it might be possible for a messed up wiring harness or bad HES sensor to run the pump constantly, since the sensor does pulse the fuel pump on every engine rotation.

    might be an interesting test if anyone has one take apart.
    #7
  8. GS Addict

    GS Addict Pepperfool Supporter

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    The turn on pump cycle is a timing function of the motronic and is not related to the HES.
    Even if the lower sensor shorts it will not turn on the fuel pump. There are more logic parameters required to initiate pump turn on.
    I would start by substituting the fuel pump relay, the contacts may be sticking.
    The horn relay would be a good one to swap with.

    That being said, if your '01 has the original HES, the wiring should be addressed.

    .
    #8
  9. Steve W.

    Steve W. Boxer Pilot

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    My guess is the aftermarket motronic chip. I remember reading they are problematic. The fuel pump relay is closed only by pin 16 on the motronic going neg. I think the OP has introduced a fault. That was the last thing he did.
    Cheers
    upload_2020-2-13_22-22-54.png
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  10. * SHAG *

    * SHAG * Unstable

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    Check your tank vent / drain under the cap for a booger. You should be able to blow air through it.
    #10
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  11. Eric Marsh

    Eric Marsh Adventurer

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    That's easy enough to do.
    #11
  12. Steptoe

    Steptoe steptoe

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    My guess is it's a problem with the chip/Motronic.

    Apropos of nothing, If you plug in a twin spark ecu into a single spark bike the fuel pump also runs continuously.
    #12
  13. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    I did not know that. Good info.
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  14. bykemike

    bykemike "ready to navigate" Supporter

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    I am in the Motronic club.

    A few weeks ago I was getting the same symptoms on my 2004 1100S bike, pump runs all the time and bike would not start. I pulled the Motronic from a 2004 1150R I have sitting right next to it and the bike runs perfectly (same number on the R motronic and the S motronic). The 1150 R now has the the S Motronic in it and the pump runs all the time and it doesn't start.

    Quick and easy to do and you can find dual spark Motronics cheap and plentiful on eBay
    #14