"hanging" idle

[Dave_in_TX]

I have a 2014 R1200GS LC with over 98k miles on it. Recently, it has developed an idle problem that resembles a sticky throttle (yes, I know the LC is "fly by wire"). Start it up and it idles at about 1200 rpm like it should. While stopped, you can play with the throttle and when its released, the idle always returns to 1200. Drive away, even a few feet, and when the throttle is closed, it will hover around 1500 rpm (sometimes as high as 1800). If I wait long enough, he idle will eventually return to 1200 rpm. A TPS reset has had no effect and all my independent BMW certified mechanic can think of is to take to the dealer for a software update. Seems to me that after all these miles, software is unlikely to be the culprit.

I have a 2014 R1200GS LC with over 98k miles on it. Recently, it has developed an idle problem that resembles a sticky throttle (yes, I know the LC is "fly by wire"). Start it up and it idles at about 1200 rpm like it should. While stopped, you can play with the throttle and when its released, the idle always returns to 1200. Drive away, even a few feet, and when the throttle is closed, it will hover around 1500 rpm (sometimes as high as 1800). If I wait long enough, he idle will eventually return to 1200 rpm. A TPS reset has had no effect and all my independent BMW certified mechanic can think of is to take to the dealer for a software update. Seems to me that after all these miles, software is unlikely to be the culprit.

I have a 2014 R1200GS LC with over 98k miles on it. Recently, it has developed an idle problem that resembles a sticky throttle (yes, I know the LC is "fly by wire"). Start it up and it idles at about 1200 rpm like it should. While stopped, you can play with the throttle and when its released, the idle always returns to 1200. Drive away, even a few feet, and when the throttle is closed, it will hover around 1500 rpm (sometimes as high as 1800). If I wait long enough, he idle will eventually return to 1200 rpm. A TPS reset has had no effect and all my independent BMW certified mechanic can think of is to take to the dealer for a software update. Seems to me that after all these miles, software is unlikely to be the culprit.

[dirtrider]

19 minutes ago, Dave_in_TX said:

I have a 2014 R1200GS LC with over 98k miles on it. Recently, it has developed an idle problem that resembles a sticky throttle (yes, I know the LC is "fly by wire"). Start it up and it idles at about 1200 rpm like it should. While stopped, you can play with the throttle and when its released, the idle always returns to 1200. Drive away, even a few feet, and when the throttle is closed, it will hover around 1500 rpm (sometimes as high as 1800). If I wait long enough, he idle will eventually return to 1200 rpm. A TPS reset has had no effect and all my independent BMW certified mechanic can think of is to take to the dealer for a software update. Seems to me that after all these miles, software is unlikely to be the culprit.

 

 

 

Evening Dave_in_TX

 

THIS, is not going to be easy to find without a GS-911 or lots of guessing & possibly some parts swapping.

 

It could be something in the throttle actuation itself sticking,  or a sensor feeding incorrect info to the  fueling computer, or an o2 sensor acting up, or some sort of vacuum leak between TB's & cylinder head, or  a dripping injector, or even a battery/charging problem (if computer senses a low system voltage it can raise the engine RPM to try to increase charging).

 

Can you tell us when it originally started (this might help us help you figure it out) --any service done to bike just before the problem started???

 

 

[Dave_in_TX]

10 hours ago, dirtrider said:

 

 

Evening Dave_in_TX

 

THIS, is not going to be easy to find without a GS-911 or lots of guessing & possibly some parts swapping.

 

It could be something in the throttle actuation itself sticking,  or a sensor feeding incorrect info to the  fueling computer, or an o2 sensor acting up, or some sort of vacuum leak between TB's & cylinder head, or  a dripping injector, or even a battery/charging problem (if computer senses a low system voltage it can raise the engine RPM to try to increase charging).

 

Can you tell us when it originally started (this might help us help you figure it out) --any service done to bike just before the problem started???

 

10 hours ago, dirtrider said:

 

Thanks, DR. I forgot to mention that a GS9111 didn't show any stored fault codes. We couldn't duplicate the problem in the shop. Charging system reads about 14.2 volts based on the voltage reading available via the dash and the voltage meter I have connected to the battery shows about the same except for when I have my Clearwater lights on full bright when it is about 13.7. These are the same voltage readings I have had since I purchased the bike. I changed oil, oil filter, and air filter about a thousand miles before the problem occurred. I also checked the valves but didnn't adjust them since they were still in spec and about the same as at the previous check. Mechanic did check for a vacuum leak by spraying carb cleaner around the intake area and that had no effect. I also posted this on advrider.com and someone there suggested a dirty potentiometer. What I find strange is that the engine needs to have a slight load on it for the problem to occur. If it could be reproduced while not moving, it would be much easier to troubleshoot.

 

[dirtrider]

1 hour ago, Dave_in_TX said:

1 hour ago, Dave_in_TX said:

Thanks, DR. I forgot to mention that a GS9111 didn't show any stored fault codes. We couldn't duplicate the problem in the shop. Charging system reads about 14.2 volts based on the voltage reading available via the dash and the voltage meter I have connected to the battery shows about the same except for when I have my Clearwater lights on full bright when it is about 13.7. These are the same voltage readings I have had since I purchased the bike. I changed oil, oil filter, and air filter about a thousand miles before the problem occurred. I also checked the valves but didnn't adjust them since they were still in spec and about the same as at the previous check. Mechanic did check for a vacuum leak by spraying carb cleaner around the intake area and that had no effect. I also posted this on advrider.com and someone there suggested a dirty potentiometer. What I find strange is that the engine needs to have a slight load on it for the problem to occur. If it could be reproduced while not moving, it would be much easier to troubleshoot.

 

 

 

Morning Dave

 

OK, battery voltage looks good so scratch that one off the list.

 

I seriously doubt that type of problem will leave any tracks (like a failure code) you are probably going to have to catch it by logging sensor data prior-to &  DURING the event.

 

You might also see if you can duplicate in statically (running in place) with trans in gear & clutch lever held in. Most electronic throttle vehicles change the throttle gain between neutral & in-gear to prevent engine flaring & unstable idle while in neutral.

 

You might even have to start guessing (like remove TB's & de-coke the throttle plates) as coked up throttle plates/throttle bores  can play strange tricks with electronic throttle vehicles. 

 

 

[Dave_in_TX]

4 hours ago, dirtrider said:

 

Morning Dave

 

OK, battery voltage looks good so scratch that one off the list.

 

I seriously doubt that type of problem will leave any tracks (like a failure code) you are probably going to have to catch it by logging sensor data prior-to &  DURING the event.

 

You might also see if you can duplicate in statically (running in place) with trans in gear & clutch lever held in. Most electronic throttle vehicles change the throttle gain between neutral & in-gear to prevent engine flaring & unstable idle while in neutral.

 

You might even have to start guessing (like remove TB's & de-coke the throttle plates) as coked up throttle plates/throttle bores  can play strange tricks with electronic throttle vehicles. 

 

 

DR, I have been unable to recreate it statically - in gear with clutch in or in neutral. However, it occurred to me that I hadn't tried it on the centerstand putting the bike into gear and letting out the clutch. 

[dirtrider]

10 minutes ago, Dave_in_TX said:

DR, I have been unable to recreate it statically - in gear with clutch in or in neutral. However, it occurred to me that I hadn't tried it on the centerstand putting the bike into gear and letting out the clutch. 

 

Afternoons Dave

 

You can try that but on the center stand extents the drive shaft U joint angles so you might get a lot of rear wheel clatter (especially at or near idle)

 

Next time it happens when riding find a safe place to pull over then do a key-off/ key-on, then restart. Then see if takes a while for the problem to return.

[Dave_in_TX]

18 hours ago, dirtrider said:

 

Afternoons Dave

 

You can try that but on the center stand extents the drive shaft U joint angles so you might get a lot of rear wheel clatter (especially at or near idle)

 

Next time it happens when riding find a safe place to pull over then do a key-off/ key-on, then restart. Then see if takes a while for the problem to return.

Since it will often occur the first time I pull in the clutch after pulling out of the driveway, I think I can rule out key-off/key-on as having any effect.

[Dave_in_TX]

Problem solved. I meant to update this thread long ago but it slipped my mind. After thoroughly cleaning the throttle bodies, the problem is gone. Although they were very dirty, I didn't see any crud on them that would explain the behavior I was experiencing.