R1100RT w/ ROUGH idle (cutting out)... suggestions?

[KTsRidin]

I’m headed to MI and a trip around the Great Lakes into Canada. At the UN we synched my R1100RT’s throttle bodies, but the idle is still REALLY rough to the point that it cuts out at lights and even in hot weather or when I pull in the clutch for an extended moment before switching gears.

 

I’ve driven through a ton of rain and not had any problems so I’ve been told it can’t be my sensor. I’ve had my fuel filter changed not too long ago, so I’m thinking that’s not it. I’ve bought gas from a large number of different retailers so I don’t think it’s a quality issue there.

 

Here’s the kicker, I don’t have an O2 sensor (European model), hence it’s an open (not a closed) system.

 

Any ideas?

 

As always, thanks for your insights,

Kirsten

[Stan Walker]

Any ideas?

 

Low rpm at idle (s/b 1100 - 1150) rpm.

 

Spark plugs, spark plug wires, coil, all come to mind, as possibilities.

 

TB air leaks? Have you checked for that? I hope you have capped the two ports where you hook up the tool used to sync the TB's.

 

Motronic, would be another, along with the sensors and wiring that feed it information.

 

I wouldn't rule out the HES. They can be temperature sensitive.

 

I'm sure there will be others.......

 

Stan

[smiller]

Could be a lot of things, Stan's got a good list started. If it runs poorly at idle only and runs OK at higher speeds you might also check the TPS (throttle position sensor) setting.

[Mudman]

In addition to the other thoughts;

 

1.Air leak between throttle body and head. Often the bands loosen. If the bike is over 5 years old the throttle stub pipes (rubber) are often cracked and leaking enough air to upset the idle. Both brass air bypass screws should be close to 1 1/2 turns out, If they are way off you have a problem to correct first.

 

2. One of the throttle cables is not seated into the ferrel on top of the throttle body. Make sure both are seated.

 

3. A small rock or other debris caught between the throttle bellcrank and cable. Dig in the "V" where the cable rides with an awl. Often something small picked up from the road is lodged between the cable and pulley.

 

Good Luck

[2wheelterry]

I also had a severe rough idle that would stall the bike, similar to what you describe. The idle would swing 200 RPM. It hasn’t stalled due to a rough idle in a while. The following are the things that I believe helped, each providing some incremental improvement.

 

Ignition timing was off a bit

Added the Techlusion (if I were doing this again, I’d do all the others before doing this)

Did a good throttle body synch

Adjusted the throttle position sensor

Did the left cam chain tensioner upgrade

Installed Autolight AP3923 plugs

[DavidEBSmith]

Look at the last thing you touched. Check the throttle cables, make sure nothing's interfering with the action of the throttle, check the caps or hoses where you attach the Twinmax or whatever.

 

Is it better if you put the fast idle on? If so, that would indicate some mechanical issue or that the idle is set way too low.

[SWB]

2. One of the throttle cables is not seated into the ferrel on top of the throttle body. Make sure both are seated.

 

Kirsten: DO double check this, and if you don't totally understand what it means, ask. Happen to me the first time I had the tupperware off the bike. The bike sounded like a truck. I was making an appointment to trailer the bike into a local dealer, and I described the problem in an email, and then in person to the service manager. While the service manager was explaining how the cables could "hitch" above the ferrel, showing me on a GS out in the lot, and that it threw the throttles out of sync, the other service writer looked up from his computer as we returned to the office and said "were you the guy with the rough running RTP ....hey, check to be certain the throttle cables are both seated ...". Turns out that it's the #1 problem that pops up after an ... um .. inexperienced wrench removes the tupperware. Checking this is the last step I do before I put the bike back together, every time.

 

Finding a rock or other obstruction in the throttle cable junction box will do the same thing, i.e. throw the throttle balance way out of whack.

 

I would have expected you to notice the problem as soon as you had the bike back together, it it's the throttle cable not seated. If it happened as you were riding .. maybe something got into one of the wheels controlling the throttle cables. But as the others said.. could be a lose spark plug wire at either the ignition coil or plug .. or lots of other things.

[KTsRidin]

Thanks all - it's the shop who's been doing the work (but I know that doesn't necessarily rule out anything). At the UN we did another sync to be sure that wasn't the issue. At 1 1/2 turns the idle was just at 1,000 RMP (but we were at high elevation and I live at sea level so that was good). The caps are on the TB where the TwinMax was used and I just had the shop replace the rubber throttle stub pipes along with the o-rings. When we did the sync I tightened the hose clamps and so they might have backed out again. I'll check.

 

I'm not sure about the cables you all are talking about so I'll hold off on that until I'm with a wrench and see what the deal is.

 

Thanks for your thoughts,

Kirsten

[SWB]

I'm not sure about the cables you all are talking about so I'll hold off on that until I'm with a wrench and see what the deal is.

 

See attached photo of my right throttlebody. To the right center of the pix, you can see the throttle cable bracket, with the wheel peaking out from below, and the ferrel and retaining nut above the bracket, and the cable sheath above the ferrel seating into the ferrel. THAT's what it should look like on both sides (maybe a bit cleaner, but ...).

 

If you can see the throttle cable between the ferrel and the sheath, the cable sheath is riding on the top of the ferrel, rather than seating down into it, and you've found your problem. Check both throttle bodies. All you have to do is nudge the cable, and it'll pop up and out of the ferrel, effectively resetting your throttle balance out of adjustment. (This photo's an archive one, and I don't have my bike's tuperware off now. Maybe someone with a GS can pull their cable up and snap a shot to give you a better idea.)

 

Hope this helps.

 

[KTsRidin]

OOOH - that's perfect - THANKS!

 

Checked that when the tupperware was off, had a good teacher (thanks Boney). Both sides were good. I'm in West Branch, MI now and, while it's still running rough, I went through serious rain and a huge puddle at an on-ramp (water over the shield), and she pulled me straight through. I'm thinking, from what I've heard you all talk about, that it's still not the sensor (can you say, I'm reallllllly hoping it's not that) so I'm thinking it's the sparkplug cables.

 

Any additional hints always welcome! Thanks for continuing my learning,

Kirsten

[SWB]

OOOH - that's perfect - THANKS!

 

Checked that when the tupperware was off, had a good teacher (thanks Boney). Both sides were good. I'm in West Branch, MI now and, while it's still running rough, I went through serious rain and a huge puddle at an on-ramp (water over the shield), and she pulled me straight through. I'm thinking, from what I've heard you all talk about, that it's still not the sensor (can you say, I'm reallllllly hoping it's not that) so I'm thinking it's the sparkplug cables.

 

Any additional hints always welcome! Thanks for continuing my learning,

Kirsten

 

What do the plugs look like? If you've got a lot more oil or carbon on one than the other, then it may be a plug or plug wire. Problem is that you're on the road. You could check the wires' resistance, but it would mean stripping the tuperware off, and if the wire's bad, then what? You can't get them at Walmart (though, in truth, you might be able to reuse the terminal, cap, and some new plug wire to make a new one in a pinch. It'd mean cutting up the wire, and if it doesn't work out, you're pushing the bike).

 

Probably best to just check into the service center of a local BMW dealer on Weds (if you're still on the road), bite the bullet, and let them fix it for you.

 

My understanding of the HES (which is what I assume you mean by "sensor"; you said your bike comes without the O2 sensor, so that should not be a factor) is that it's pretty much an "on or off" thingy. If you're bike is pumping fuel and the bike starts, the HES is not dead. (Wounded maybe.. I dunno.)

 

Again, all this assumes that your TB synch was done correctly. From your original description, it sounded like your bike was running fine until the TB synch at UN. So, a step or two could have been skipped. If it runs poorly post-TB synch, it's time to do another one.

 

Good luck!

[KTsRidin]

Thanks for your thoughts Scott. The TB synch at the UN was because it was running rough and even the shop hasn't gotten it running better (the shop lord says he'd like to put it on a gas analyzer). So, I’ve lived with it like this for a while so I’ll live with it like this for a bit longer until, hopefully, it gets worked out. Yep, the “sensor” is the infamous HES that I’ve heard horror stories about leaving folks stranded. I love this bike and just want it to run better like it did some time ago (before it starting burning oil too).

 

I was hoping I’d (read “the shop”) missed because that was so obvious it was overlooked and you all would go, “You know, it’s the ______.” Still maybe something simple. I’m planning on stopping and seeing Tom Rowe at Betty’s in a few days, so something may come of that.

 

I’ll post again when something pans out… perhaps my woes can be a learning lesson for others besides me. All in all, I’m really enjoying learning more about my bike and how it works. Thanks to you all for playing the part of “Kumu” (that’s teacher in Hawaiian)

 

Cheers,

Kirsten

[flat_twin]

Thanks for your thoughts Scott. The TB synch at the UN was because it was running rough and even the shop hasn't gotten it running better (the shop lord says he'd like to put it on a gas analyzer). So, I’ve lived with it like this for a while so I’ll live with it like this for a bit longer until, hopefully, it gets worked out. Yep, the “sensor” is the infamous HES that I’ve heard horror stories about leaving folks stranded. I love this bike and just want it to run better like it did some time ago (before it starting burning oil too).

 

I was hoping I’d (read “the shop”) missed because that was so obvious it was overlooked and you all would go, “You know, it’s the ______.” Still maybe something simple. I’m planning on stopping and seeing Tom Rowe at Betty’s in a few days, so something may come of that.

 

I’ll post again when something pans out… perhaps my woes can be a learning lesson for others besides me. All in all, I’m really enjoying learning more about my bike and how it works. Thanks to you all for playing the part of “Kumu” (that’s teacher in Hawaiian)

 

Cheers,

Kirsten

 

 

Kirsten, I was there when we checked the TB sync in Gunnison. From what I recall the problem was an occasional stumble at idle that would sometimes cause the engine to die at a stop light. Is it now running rough all the time? It sure sounded like an ignition issue when we were talking about it earlier.

My 99RT (55k miles) also running without the O2 sensor, has done this only a couple times in the last four years. Once it died at a stop, otherwise it's as if the ignition was turned off for just an instant. Since it's so infrequent, I haven't tried to trouble shoot it.

I'm in north central Ohio if you need any assistance on your Great Lakes tour. Mathias Cycle BMW in New Philadelphia, Ohio is the best in the area should you need a dealer.