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1998 BMW R1100R

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by karingaa, Jan 29, 2016.

  1. Hello,

    You guys recently helped me with another issue, but unfortunately I now have an idling issue. This is my first fuel injected bike and it has started to suddenly die while idling. I can start the bike and it will run at around 1100RPM with no sputtering and after several minutes will all of a sudden die. It did this today on my way home at a stop light. Bike will start right up, but when the incident first happened would die as soon as RPM dropped close to idle speed. I had to give some gas while starting to get going and rode the bike home. When I got back it would start and idle with no issues, but would again die all of a sudden a few minutes in.

    Some history:

    I had to replace the fuel pump and the plate holding the whole fuel gauge assembly. Previous owner had installed wrong hoses inside the tank so I replaced those as well. The lining in the tank was in really bad condition, so I cleaned the whole tank out with apple vinegar before re assembling. The bike sat for about 2 months with an almost empty tank because I had to constantly take it off while trying to figure out an issue with no spark. No doubt there is some surface rust now on the inside of the tank due to lack of lining, but it doesn't look too bad.

    I have noticed that one of the small hoses running from the fuel inject to somewhere above the engine looks weathered and is soft to touch.

    Should I be running fuel cleaner through the tank or is there another possible issue that is causing the issue?

    Thank you in advance.
  2. God! I read your post heading as ' bmw rider dies while idling' ! Sorry don't have an answer
  3. upload_2016-1-29_13-6-24.
  4. This may be my fault..... if so, sorry!

    When I told you about rebooting the Motronics unit, I forgot to tell you about resetting the throttle position sensor.

    If you can cut the power to the Motronics box, either by disconnecting battery or pulling the appropriate fuse (sorry again, can't remember which one it is.) anyhow leave the box with no electricity for a few minutes, then reconnect power to it.

    Now, you switch ignition on, but don't try and start it. You smoothly roll the throttle from nothing to full on, two or three times.

    Now switch ignition off. You have now reset the throttle position sensor.

    Ignition on, and start beast.....

    If the problem has gone away, great.

    If it hasn't, my next suggestion is synchronizing the throttle bodies.

    Afraid I don't know how to do this myself, so I can't explain it, but, if they are out of synch, you can get the symptoms you describe.
    • Informative Informative x 1
  5.  Top
  6. #6 GreyBM, Jan 29, 2016
    Last edited: Jan 29, 2016
    There are YouTube vids on how to sync the throttle bodies.

    And if you have the owners handbook it should tell you which fuse is on the moronic so circuit. According to Haynes it should be a 10 amp fuse 5th from the left as you sit on the bike.
  7. Thank you for the suggestion, I will definitely try it out. I recently switched out my oil temperature sensor which had gone bad and all diagnostic readings were good (4444). Finally had a chance to go ride today and about 10 minutes in the same exact issue started occurring where bike dies at low RPM or idle. Barely made it home. Bike kept dying on me and I had a hard time getting it into 1st without it dying. Also the ride was really jerky even in 2nd and 3rd gears. I will definetly give your suggestion a try this week.

    Any idea why this issue would be occurring only when bike is fully warmed up? Just trying to get a better understanding of what exactly the throttle position sensor does.

    Than you for your time in advance.
  8. Thankfully no :) I did however have to put the bike on its side because it died on me in a really weird incline while pulling into my driveway at slow speed :( No damage, but definitely embarrassing.

  9. The throttle position sensor business just re-establishes the relationship between the twist grip movement and the actual throttle at the throttle bodies.

    To be honest, I've never, knowingly, ridden my BMW without that business being set-up, so I can't swear to what a bad setting feels like.

    I have ridden my bike when the throttle bodies were out of balance, and that did give symptoms very like what you describe.
  10. You can do a quick for balance with a long length of clear plastic tubing. Google can show how and there was a recent thread here on Netrider. There are also plenty of YouTube vids on how to balance.

    However I can't see why being out of balance would let the bike run for 10 mins and then cut out. out of balance will effect performance and vibration but dunno why it would suddenly get worse.

    Think I would be taking it to a workshop for proper diagnosis. Where are you located karingaakaringaa ?
  11. I am in Hawaii and unfortunately I don't have a means to get the bike to a shop.
  12. I restarted the bike after I disconnected the motronic control unit and did the throttle sensor reset and the bike died while idling for about 3-5min. Started the bike up again and died a few minutes later and the next time I started it ran without any problems. So maybe i simply didn't notice the bike not performing when I went out for a ride because I was in higher gears and RPM. i'll look into the balancing vids and post the outcome.
  13. Starving of fuel?

    Clogged filter or defective fuel pump?

    Hawaii ... hmmm don't think the dealers here are going to be able to help you.

    Do you have a local branch of a BMW Club? Would be worth asking them the question.
  14. Dunno about the OP, but, when I picked up my BM from the workshop, it had been sitting for a while.

    I used the Fast Idle switch to start it, and rode off.

    It felt OK at that stage, but, when I switched off the F.I. it started to play up a treat.

    I managed to get it back to the workshop.... just!

    Once there the boss immediately said it was the balance..... pulled out some "magic" device, rebalanced the throttle bodies correctly, and off I want happy as the proverbial pig in poo.

    Have no idea how cold it gets in Hawaii..... does one use the Fast Idle switch much there? Dunno.
  15. My understanding is that on these bikes the fast idle switch is literally just that. It isn't a choke that enriches fuel, it just turns up idle in the same way that giving a bit of throttle does.

    I guess if things aren't right and motor is trying to stall it will be more likely to actually stall at lower revs. But if it was just unbalanced throttle bodies I would expect it simply to run rough throughout band not suddenly after ten minutes.

    Even without a balancer you could note position of screws and give one a turn to see if things got better or worse. If original position is noted you can always set it back.
    • Agree Agree x 1
  16. Thank you for the insight. I will have to dig deeper into it. I started the bike cold or as cold as it gets in Hawaii at 3PM (probably 80F or so) and he bike started and immediately turned off). This is really starting to drive me nuts, but I will figure i out. Thank you again for the insight.
  17. Unfortunately the BMW dealer here refuses to work on anything older than 2002 if I remember correctly. I was thinking of replacing the fuel pump with another one that I have sitting around to see what happens. The other pump isn't a BMW pump, but it worked before. The one that is in there right now is from a replacement fuel gauge plate that I purchased. It was the original BMW pump and seemed to work so I left it on. Worth a try, because now it is dying immediately on cold start sometimes. Not completely completely cold since it's about 80+ degrees outside :)
  18. I do use the idle switch on the left hand handle bar if that's what it is called. Usually will take my RPMS to about 2000 and after about 30 seconds I turn it off and when working properly will drop to a steady 1000 RPMS. That is before this idle issue began. Right now is probably the coolest weather of the year and we are no lower than 65F at night if that. I'll need to look up how to do a throttle body balance.
  19. On 1100 Beemers I think the fuel pump only stays on briefly after you turn on the ignition. The fuel pump fires up again once the Crankshaft is rotating.
    You should check the spray from your injectors, by removing them and leaving them connected. This should tell you a few things. The condition of the Injectors, the condition of the Fuel Pump, the condition of the Fuel Filter, and whether the signal from the Crankshaft is good. Take care with atomized Fuel ! !

    On my old 1100rt I used to get the "stone in the Throttle Pulley" It would idle ok, but would run rough.
  20. Is it only going to spray as I crank right? You are talking about unplugging the injector, but leaving the electric plug right? Sorry for all the questions, this is the first bike I have owned with injectors so I am a bit new to this.