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1999 R1100RT runs bad, need advice.

bcusack

Member
1999 R1100RT 62K miles. Running beautifully until a fill up and after about a mile or two had some problems, would not idle and had no power to pull hills unless I kept the revs up. Under no load on flat roads seemed to run ok. Got to my destination and it would not start once cooled. Got the bike home and removed all the old gas and put fresh gas in, no difference, I?m now pretty sure the fill up was a coincidence. The fuel pump fires up and pressurizes when the systems is closed and freely pumps fuel through the system and out into a container the few seconds it runs when the key is turned. The plugs are new but the spark looks weak , I replaced the plug wires, the coil measures fine yet I had it stressed tested locally and it works well, pulled the BBS and had a little carbon buildup but not bad. The bike will start by holding the throttle open a bit but runs like crap. I have not adjusted the valves yet but I doubt they would have changed adjustment so suddenly. I have not done a TBS as it is not running well enough to do so but at higher revs the twin max pulls evenly.

I've been through everything and the only thing that eludes me and I don't think is normal is the weak spark. I get a weak yellow or orange spark from the plugs not a nice white or blue snappy spark like I would expect. The weak spark does seem to change in intensity from cold to warm, somewhat weaker when warm. The spark sometimes is more like static and dances all along the electrode instead of jumping at the gapped end. I'm leaning toward an intermittent HES. The HES was replaced 4 years and 30 k miles ago. I did pull the HES and peeled back the insulation to look for the deteriorated wires I had seen when I replaced it the first time. The wires seem soft and pliable with only the faintest hint of the green corrosion you see around electrical connections. The HES also seems ok by the fact that it causes the injectors to spurt and the plugs to fire. When the HES failed the first time the bike just died. This time the bike starts hard and runs badly. Would the intermittent HES cause the weak spark? I know the HES on these machines are troublesome can they fail after 4 years? Should I be looking for other problems?

Other info; Two weeks and two tanks of gas before I had trouble I did replace the fuel lines, filter, etc. I opened it again yesterday just to see if I may have messed something up and it all looks ok.

I do use these forums a lot for help and I do appreciate any help or insight you can give me.
 
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WOW! Did you read my post on another BMW forum? I am in the middle of the exact same issue. First thing I did was check your location to see if you might have used the same gas station as me. Mine is a 2001 R1100RT with 105,000 miles. Same sequence of events. Running great; fill up at the end of my ride, then it won't idle and runs like garbage. I have replaced fuel lines and filter, fresh gas, good plugs. No improvement. My HES has never been replaced and never given a hint of problems - until possibly now.

I will watch this thread carefully - let's share the fix if either of us gets there first.
 
If either of you has, or can borrow a GS-911, there are a lot of things that can be ruled in or out. The process would be to attach the 911, select all realtime values, the LOG to CSV file. Start the bike, run for 5-10 minutes, examine the data and see what the input sensors are doing. If you get that far and would like it, I'd be happy to have a look at the files.
RB
 
And a follow up question, are you watching fuel flow in the return line going back to the tank or in the high pressure line coming from the tank?
 
Both of our bikes are R1100RTs; I'm not sure how much data the GS-911 can get off of the R11 bike system. I don't have access to a GS-911.

I am looking at fuel flow at the fuel injector. I have looked at it with the injector pulled out of the throttle body, and also with the fuel line unclipped from the injector. So I have seen fuel flow straight out of the fuel line, and fuel spray from the injector tip when the starter gets cranked.
 
Thanks Roger,

In my case it is the return line to the tank, after the fuel distributor. I also get a nice even spray from both injectors.
 
Both of our bikes are R1100RTs; I'm not sure how much data the GS-911 can get off of the R11 bike system. I don't have access to a GS-911.

I am looking at fuel flow at the fuel injector. I have looked at it with the injector pulled out of the throttle body, and also with the fuel line unclipped from the injector. So I have seen fuel flow straight out of the fuel line, and fuel spray from the injector tip when the starter gets cranked.

I always forget that the GS-911 doesn't retrieve and log realtime values for the R1100. Thanks for reminding me. Having one wouldn't help that much now. If you do a search you can find out how to get the Motronic to read out its errors and there's also a TPS cal signal at the diag connector.

Once you remove the injector from the fuel distribution the pressure is released and even with split hoses I got a pretty good stream of fuel. Injector spray was there but anemic. When you check the fuel flowing in the return line the pump and hoses have to be in good enough condition to force fuel past the 43 psi regulator. I'm not saying for sure that you have a fuel problem, just that you need to look at return flow to judge the system's integrity,
 
1100 motronic

I always forget that the GS-911 doesn't retrieve and log realtime values for the R1100. Thanks for reminding me. Having one wouldn't help that much now. If you do a search you can find out how to get the Motronic to read out its errors and there's also a TPS cal signal at the diag connector.

I don't remember all the steps, still looking. You short something and it starts pulsing out stored codes.
I just used an analog voltmeter to detect the pulses...

Please see pages 71 through 73 of:
http://ibmwr.org/r-tech/oilheads/R11Manual/Oilhead_Maintenance_2-25-02.pdf
 

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I always forget that the GS-911 doesn't retrieve and log realtime values for the R1100. Thanks for reminding me. Having one wouldn't help that much now. If you do a search you can find out how to get the Motronic to read out its errors and there's also a TPS cal signal at the diag connector.

Once you remove the injector from the fuel distribution the pressure is released and even with split hoses I got a pretty good stream of fuel. Injector spray was there but anemic. When you check the fuel flowing in the return line the pump and hoses have to be in good enough condition to force fuel past the 43 psi regulator. I'm not saying for sure that you have a fuel problem, just that you need to look at return flow to judge the system's integrity,

Roger, with what you are saying and what I am seeing I believe I'm ok on the fuel side of the equation. How would you describe "anemic"? Mine sprays a fine mist in a V pattern maybe even conical. Any thoughts on what I feel is a weak spark? Am I chasing gremlins? I will try to pull the codes but I'm concerned they may be corrupt as I've had several components apart at this point, I'm not sure how the system stores codes.

Thanks again.
 
Roger, with what you are saying and what I am seeing I believe I'm ok on the fuel side of the equation. How would you describe "anemic"? Mine sprays a fine mist in a V pattern maybe even conical. Any thoughts on what I feel is a weak spark? Am I chasing gremlins? I will try to pull the codes but I'm concerned they may be corrupt as I've had several components apart at this point, I'm not sure how the system stores codes.

Thanks again.

I agree it seems as if you are lokay on the fuel side since you are pushing fuel up the return line. It would be good if someone with R1100 HES failure experience could weigh in. It sounds more like that than fuel.
 
Roger, with what you are saying and what I am seeing I believe I'm ok on the fuel side of the equation. How would you describe "anemic"? Mine sprays a fine mist in a V pattern maybe even conical. Any thoughts on what I feel is a weak spark? Am I chasing gremlins? I will try to pull the codes but I'm concerned they may be corrupt as I've had several components apart at this point, I'm not sure how the system stores codes.

Thanks again.

I agree it seems as if you are okay on the fuel side since you are pushing fuel up the return line. It would be good if someone with R1100 HES failure experience could weigh in. It sounds more like that than fuel even though you repaired it before.
 
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My second bike just experienced this. Was so bad I wasn't sure I could get home. Then it would clear up. Periodically it would do repeat this. It was due in for some work at the place that also does my K RS. The first thing that was checked were the battery connections. They were loose. That fixed it. In reading about similar issues, a chaffed wire will sometimes produce a similar result. So check your wiring just to be sure all is solid. The guy that knew this says he also checks that first when a BMW comes in with some reports of sudden stumbling and running very poor.

Most likely not your issue but still something to remember to check.

NCS
 
Roger, with what you are saying and what I am seeing I believe I'm ok on the fuel side of the equation. How would you describe "anemic"? Mine sprays a fine mist in a V pattern maybe even conical. Any thoughts on what I feel is a weak spark? Am I chasing gremlins? I will try to pull the codes but I'm concerned they may be corrupt as I've had several components apart at this point, I'm not sure how the system stores codes.

Well, I narrowed my suspect parts down to ignition coil or Hall Effect Sensor. Independently, somebody sent me a message - said that my symptoms (same as yours) sounded like a bad coil. I chased down a few auto web sites with descriptions of bad coil symptoms and except when the coil totally fails, the symptoms of a bad coil are exactly what you and I are experiencing. So, I ordered a replacement coil - should have it in hand middle of the week and I'll report back the results.
 
For my bike, it wasn't the ignition coil. Too bad because it was so easy to replace and it was fairly inexpensive. So, that left me with the HES - or something really bad in the engine.

I pulled the HES this morning and like so many others, the wires inside the harness alongside the plate and strain relief area, those wires had brittle insulation which cracked and broke off. I'm clearly not good enough with a soldering iron, so I ordered a new replacement HES. I'll report back after the new HES is installed.
 

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Hi All, It?s been a few weeks since I posted up any progress here, personal and work commitments have kept me away from the bike. Anyway, today I was able to get back at it and still thinking I was chasing an ignition problem I found the bike would run as well on one cylinder as it did with both at low rpms with the right plug wire removed. It did seem to smooth out and run well with no load above 3000 rpm with both plug wires in. Still seeing a clear difference in the spark I continued to chase the weak spark theory. I picked up a spark gap tester and was happy to find the right spark was much weaker than the left although it did seem to change in intensity on either side. As a final conclusive test and knowing this bike has, I believe, a wasted spark system, I switched the plug wires at the coil expecting to see the side that ran the bike switch from the left to the right, it did not and still found It could start and run with only the left side plug wire in (and the weaker spark) and not vice versa.

As I thought the above was odd I did a compression test and the left cylinder was above spec at 175 lbs. and very little compression maybe 20 lbs., on the right. Actually feeling good about this I figured I would find maybe the valves were to tight and held open but when I pulled the valve cover all seemed to be in order and operated normally. The valve clearance was good with all four valves closed. I assume if there is carbon built up on the valves I would see a difference in the gap with the valves closed. So I'm perplexed again and I suppose the next move should be a leak down test. Is there any normal reason I would see what I'm seeing? Any advice? Thanks in advance.
 
Still waiting for a solution!

I ran out of ideas. I replaced the Hall Sensor with a new one from Beemer Boneyard and my problem - similar to yours bcusack - my problem persists. After three weeks of chasing possible solutions I have run out of tools and skills. I had my RT picked up by my dealer and they will hopefully get to it this week. I'll report back when I get "the call."
 
Hi All, It?s been a few weeks since I posted up any progress here, personal and work commitments have kept me away from the bike. Anyway, today I was able to get back at it and still thinking I was chasing an ignition problem I found the bike would run as well on one cylinder as it did with both at low rpms with the right plug wire removed. It did seem to smooth out and run well with no load above 3000 rpm with both plug wires in. Still seeing a clear difference in the spark I continued to chase the weak spark theory. I picked up a spark gap tester and was happy to find the right spark was much weaker than the left although it did seem to change in intensity on either side. As a final conclusive test and knowing this bike has, I believe, a wasted spark system, I switched the plug wires at the coil expecting to see the side that ran the bike switch from the left to the right, it did not and still found It could start and run with only the left side plug wire in (and the weaker spark) and not vice versa.

As I thought the above was odd I did a compression test and the left cylinder was above spec at 175 lbs. and very little compression maybe 20 lbs., on the right. Actually feeling good about this I figured I would find maybe the valves were to tight and held open but when I pulled the valve cover all seemed to be in order and operated normally. The valve clearance was good with all four valves closed. I assume if there is carbon built up on the valves I would see a difference in the gap with the valves closed. So I'm perplexed again and I suppose the next move should be a leak down test. Is there any normal reason I would see what I'm seeing? Any advice? Thanks in advance.

I've read in other threads that a spec of carbon can hold a valve open, causing this. I think it was posted by Paul Glaves. Others with more experience will have to comment.

I ran out of ideas. I replaced the Hall Sensor with a new one from Beemer Boneyard and my problem - similar to yours bcusack - my problem persists. After three weeks of chasing possible solutions I have run out of tools and skills. I had my RT picked up by my dealer and they will hopefully get to it this week. I'll report back when I get "the call."

The way your HES looked it seemed like you'd found the problem. Did you reset the Motronic by disconnecting the battery or fuse 5 after replacing the HES? Will be interested in hearing what the dealer comes up with.
 
As I thought the above was odd I did a compression test and the left cylinder was above spec at 175 lbs. and very little compression maybe 20 lbs., on the right.

You probably have a burnt valve, but it could be a holed piston. If you remove the exhaust header, you can see the edges of the exhaust valves and might be able to see a problem.
 
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