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Another runs fine then dies syndrome...


elkroeger

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I didn't want to pollute Torontonian's thread where his bike runs fine and dies, but I'm having a very similar issue.

 

'96 1100RSL, 65K. Starts and runs fine. Commuter bike, daily driver. Dies intermittently. Seems most common when leaving work, it just dies at 2000 - 2500 rpm, after about a mile. After a couple quick episodes, it won't do it again for a day or two.

 

RID stays lit, no dash lights. It just dies and restarts on compression a moment later. If I pull over and disengage the clutch, it stays dead, but then I can hit the starter, and it fires right up.

 

It will backfire during the episode sometimes, which I believe tells me I'm losing the spark for a moment, as opposed to fuel problems.

 

We did replace the HES unit a couple months back, along with a length of fuel hose in the gas tank. That Hall sensor is a BOSCH unit I got from Beemer boneyard, as opposed to a BMW branded unit. I figured they're likely to be the exact same thing.

 

Other than that, I had a full service done and new battery in January.

 

Any thoughts?

 

 

 

 

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Morning Eric

 

The first thing that comes to mind is that your o2 sensor is acting up as it heats & comes on line. (maybe try riding with the CCP removed or the o2 disconnected)

 

There was also a BMW service bulletin on the early 1100R bikes (mainly 96) that pertained to a low RPM glitch in the Motronic that allows a stall as the bike was being ridden from cold up to operating temperature. I don't have the bulletin handy (it's an old paper one) but it was about how the Motronic acted when the engine sensors reached a certain string temperature. (your "just dies at 2000 - 2500 rpm" seems a little high for this bulletin but if it is dying at dropped throttle then m-a-y-b-e.

 

 

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Hmmmm, that O2 sensor may have some merit. It was disconnected when I bought it 10 years ago, and just reconnected in january while I had it in the shop.

 

Perhaps that's why it was disconnected in the first place. I'll give it a try, and report back. Thanks DR!

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I got the O2 probe disconnected yesterday. About 4 hours of riding, broken into about four distinct rides, with a cool down period, and nary a cough or sputter. Thanks again! :-)

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Here's a possibility if you still have a charcoal canister. If you don't, you can ignore the comments.

 

After the bike warms up and the O2 sensor comes on line, the purge valve for the canister is opened. If you have gasoline in the canister when the valve opens you will quickly stall the bike.

 

I haven't tested this but it may be that if the O2 is disconnected, it doesn't open the purge valve because it needs closed loop operation to keep the AFR right. So I can see the possibility that disconnecting the O2 is keeping the purge valve closed.

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Dang, it did it again the other day. Couple times in a row.

 

It does appear to occur less often than when the o2 sensor was connected.

 

It does still have the charcoal canister. I know a lot of people jettison those things. You think it'll help if I get rid of it?

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I don't believe this was offered up yet so try this.

 

Pull your fuel pump relay. Spray the relay contacts and the relay socket with quick drying electrical contact cleaner. Plug and remove the relay another couple of times. You could do this and at the same time swap the horn relay with the fuel pump relay. Horn relay hardly ever used, fuel pump relay used all the time.

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Dang, it did it again the other day. Couple times in a row.

 

It does appear to occur less often than when the o2 sensor was connected.

 

It does still have the charcoal canister. I know a lot of people jettison those things. You think it'll help if I get rid of it?

 

Morning elkroeger

 

Worth a try anyhow-- you don't have to actually remove your charcoal canister as you can just remove the purge hose from the purge valve (L/H side of bike) then plug the hose that runs from the valve to the throttle bodies with a golf tee or ??.

 

If problem then goes away you can do a full charcoal canister removal.

 

If you feel like some more troubleshooting you can make up a 12v test light with 2 long pig tails then zip tie or tape it to the dash or handlebars.

 

Then use that test light to monitor fuel injector power (between green wire at one of the fuel injectors chassis ground), then monitor coil 12v power. Or monitor about any other 12v system you suspect.

 

If disconnecting the o2 sensor changed the stalling to less frequent then fueling control input (like engine sensors) or something in the adaptives would be near top of my list to check.

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I'll have to scratch my noodle about it, and fiddle with it on the weekend. Ingenious idea about the trouble light zip tied to the dash.

 

One other observation, these stalling episodes, while they may be several in short succession, I'm pretty confident that once it's passed, it doesn't occur again until the next trip. So that warming up to temp with the o2 probe sounded like it was making sense.

 

On the other hand, it did it once, within a minute of starting cold, and another time well into a trip at full normal operating temp.

 

Thanks again guys.

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I'll have to scratch my noodle about it, and fiddle with it on the weekend. Ingenious idea about the trouble light zip tied to the dash.

 

One other observation, these stalling episodes, while they may be several in short succession, I'm pretty confident that once it's passed, it doesn't occur again until the next trip. So that warming up to temp with the o2 probe sounded like it was making sense.

 

On the other hand, it did it once, within a minute of starting cold, and another time well into a trip at full normal operating temp.

 

Morning elkroeger

 

There is always that service bulletin on engine stalling after ride away from cold start (that sort if fits your problem).

 

Have you tried leaving the choke (fast idle lever) on until you are past the normal stalling point?

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  • 2 weeks later...

Hmmm... Google doesn't know everything. Where are you finding these service bulletins?

 

Another observation: Tachometer continues to register rpm while the motor has stalled, at speed with the clutch out (thus, the engine is being turned by the rear wheel).

 

 

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Hmmm... Google doesn't know everything. Where are you finding these service bulletins?

 

Another observation: Tachometer continues to register rpm while the motor has stalled, at speed with the clutch out (thus, the engine is being turned by the rear wheel).

 

 

Morning elkroeger

 

Mainly at your BMW dealer (if the dealer will take the time to look them up for you) or if the dealer has an older tec on staff that has a good memory.

 

Or having a friend that works for BMW.

 

Sorry I can't post or send any BMW service bulletins as they are proprietary to BMW & I don't have permissions to do so. It is also against this web site's policy as well as against the law to post proprietary documents that I don't have permission to release.

 

 

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  • 4 months later...

Update - after months of riding around with an occasional stall, I think we've gotten to the bottom of it. Turns out that the coil was out of spec. Ohms were a little low, which I believe resulted in a weak and/or no spark. Got a new coil. It's been a couple weeks now, and not one stall.

 

knock on wood....

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Update - after months of riding around with an occasional stall, I think we've gotten to the bottom of it. Turns out that the coil was out of spec. Ohms were a little low, which I believe resulted in a weak and/or no spark. Got a new coil. It's been a couple weeks now, and not one stall.

 

knock on wood....

 

I had this issue on my old 1100 RT - took it out for a ride and after 20 mins, it cut out. Let it cool down after checking to see if there was anything obvious (there wasn't), and started it up again - decided to high tail it straight home - cut out again 15 mins later on a hill - let it cool down and it fired up again so home I went.

A quick phone call to Andy (Boffin of this parish) and he suggested it may be the coil, so I got a reconditioned one and Andy came round to help me fit it.

We did have a laugh at our own stupidity though, as after fitting it we could not get the bike started - Andy suggested I put the kettle on whilst he had a rethink, so I duly came back out 5 mins later with the tea. After standing there looking at the bike for a further five mins, I suddently spotted the serious problem..............I had inadvertently knocked the kill switch to the off position and neither of us had noticed.

 

Just goes to show that sometimes ya can't see the obvious for looking!!

 

Never had an issue with the coil again, nor the bike until the sad day when the dreaded spline strip incident which eventually resulted in me getting rid of the bike and getting the 1100 R that I now have.

 

Steve

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