R1150GS stalling issue

As the title says. It is my friend's 2004 R1150GS twin spark without ABS and low mileage, 35.000 Km. The bike runs very sweet, but the problem is when stopping after a good highway run it will stall. Starts right away without any issue. A month ago I did regular maintenance on the bike. Changed oil, oil filter, valve adjustment, air filter, TB sync. The bike runs even better now, idles at 1.100 rpm without fluctuation but the stalling issue is still present. During the maintenance I have noticed that the air temperature sensor is broken and there was error code in the Motronic for it. I assumed that this might be the cause for the stalling issue. Two weeks later I have replaced the the air temperature sensor but the stalling issue is still present. Even more, now there is another new issue. When the bike is parked after a good run in the city and cooled down a little bit, then on the first start, within 15-20 sec the rpm will slowly drop around 700 rpm and struggles for a bit there until the rpm drop even more and stalls. On the second or third start it will recover and run without any issue.

So far I have checked the TPS, HES, Oxygen sensor, oil temperature sensor, ignition coils, drain and vent hoses and everything seems OK.

Now I'm testing the fuel pump pressure and fuel pump supply voltage. I have attached pressure gauge inline with the fuel flow hose and two voltmeters. One at the battery and the other one at the fuel pump power supply connector. I will let the bike to idle and this is what I'm getting. At around 4 bars on the temp gauge the fuel pressure is 3.6 bar, battery voltage 13.85 V and fuel pump voltage 13.34 V. As the temperature rises the fuel pressure stays the same but the voltage drops to 13.5V at the battery and 13.16V at the fuel pump with temperature around 7 to 8 bars on the gauge. Then I will turn off the engine and wait to cool down. While cooling down I can hear bubbling in the fuel tank on around 10 sec intervals. There is no pressure build up in the tank. Then I will start again the bike with temperature around 4 to 5 bars. The fuel pressure is again steady at 3.6 bar but the engine rpm will tend to drop with battery voltage at 13V and fuel pump voltage at 12.7V until the rpm drops more and stall with battery voltage at 12.9V and fuel pump voltage at 12.3 V.

Next step is to measure the fuel pressure at the fuel return hose after the pressure regulator. Anyone knows what pressure is expected here? I will remove the tank and check the hoses, fuel pump and fuel filter but before doing that I like to collect as much possible data on the fuel system before changing anything. Also I want to check the main ground wire connection at the engine while the tank is off the bike. It looks suspicions but can't reach while the tank is on the bike

Has anyone experienced such behavior on R1150GS? Any direction what to check next? Also, what is the normal charging voltage on this bike? This one has the 50A Bosch generator with elasto belt.

As the title says. It is my friend's 2004 R1150GS twin spark without ABS and low mileage, 35.000 Km. The bike runs very sweet, but the problem is when stopping after a good highway run it will stall. Starts right away without any issue. A month ago I did regular maintenance on the bike. Changed oil, oil filter, valve adjustment, air filter, TB sync. The bike runs even better now, idles at 1.100 rpm without fluctuation but the stalling issue is still present. During the maintenance I have noticed that the air temperature sensor is broken and there was error code in the Motronic for it. I assumed that this might be the cause for the stalling issue. Two weeks later I have replaced the the air temperature sensor but the stalling issue is still present. Even more, now there is another new issue. When the bike is parked after a good run in the city and cooled down a little bit, then on the first start, within 15-20 sec the rpm will slowly drop around 700 rpm and struggles for a bit there until the rpm drop even more and stalls. On the second or third start it will recover and run without any issue.

 

So far I have checked the TPS, HES, Oxygen sensor, oil temperature sensor, ignition coils, drain and vent hoses and everything seems OK.

 

Now I'm testing the fuel pump pressure and fuel pump supply voltage. I have attached pressure gauge inline with the fuel flow hose and two voltmeters. One at the battery and the other one at the fuel pump power supply connector. I will let the bike to idle and this is what I'm getting. At around 4 bars on the temp gauge the fuel pressure is 3.6 bar, battery voltage 13.85 V and fuel pump voltage 13.34 V. As the temperature rises the fuel pressure stays the same but the voltage drops to 13.5V at the battery and 13.16V at the fuel pump with temperature around 7 to 8 bars on the gauge. Then I will turn off the engine and wait to cool down. While cooling down I can hear bubbling in the fuel tank on around 10 sec intervals. There is no pressure build up in the tank. Then I will start again the bike with temperature around 4 to 5 bars. The fuel pressure is again steady at 3.6 bar but the engine rpm will tend to drop with battery voltage at 13V and fuel pump voltage at 12.7V until the rpm drops more and stall with battery voltage at 12.9V and fuel pump voltage at 12.3 V.

 

Next step is to measure the fuel pressure at the fuel return hose after the pressure regulator. Anyone knows what pressure is expected here? I will remove the tank and check the hoses, fuel pump and fuel filter but before doing that I like to collect as much possible data on the fuel system before changing anything. Also I want to check the main ground wire connection at the engine while the tank is off the bike. It looks suspicions but can't reach while the tank is on the bike

 

Has anyone experienced such behavior on R1150GS? Any direction what to check next? Also, what is the normal charging voltage on this bike? This one has the 50A Bosch generator with elasto belt.

 

 

 

 

Evening 14TLC

Top of my list would be the o2 sensor (how did you test the o2 sensor?). They can seem to work OK but can be a bit lazy to respond & cause a stall.

Did you do do new TPS relearn?-- If not then try that also.

Did it stall before the TB balance & valve adjustment work?

Are the TB throttle plate cams completely dropping back to the idle stop screws? If the throttle cable is just a bit too tight it can "base-idle" on the throttle cables then as they heat & stretch out the hot engine idle RPM drops to a stall.

Any chance a lower spark plug is fouling out. The engine will run OK on the uppers or both uppers & one lower but you can get a stall if you lose a lower plug firing.

As a rule fuel pressure, or fuel flow issues, effect the higher speed power & runability WAY before they have any effect on the idle or stalling.

One other thing that W-I-L-L cause a similar stalling is the o2 sensor pig tail running too close to, or along, the R/H lower spark plug wire. The spark RFI gets induced into the o2 sensor wiring & really fouls up the idle quality & causes stalling. (make sure that the o2 sensor pig tail isn't zip tied along or near the R/H lower spark plug wire)

Another thing to look for is the o2 sensor pig tail hanging down on the hot exhaust as that can also cause a stalling issue.

Hello dirtrider,

Good advice from you as usual :-). So, to reply

Top of my list would be the o2 sensor (how did you test the o2 sensor?). They can seem to work OK but can be a bit lazy to respond & cause a stall.

I have tested the o2 sensor with dealers diagnostics. I have a friend working at independent BMW car workshop and they are letting me use their diagnostic software. I have done the basics tests, look at the voltage fluctuation of the o2 sensor. This seems ok, but there are some other measurements that needs to be done with the o2 sensor disconnected. Will do this after I remove the tank so I can reach the o2 sensor connector. With the basic test it looks good, I have seen lazy 02 sensors on some older R1150s

Did you do do new TPS relearn?-- If not then try that also.

I keep forgetting about this. But if I remember correctly I did the TPS reset last summer when the bike started developing the issue. Than it was on rear occasions and disappeared at some point. But, then again it was winter and during the colder weather the issue was gone

Did it stall before the TB balance & valve adjustment work?

Yes. It started last summer

Are the TB throttle plate cams completely dropping back to the idle stop screws? If the throttle cable is just a bit too tight it can "base-idle" on the throttle cables then as they heat & stretch out the hot engine idle RPM drops to a stall.

Already checked.No issue there

Any chance a lower spark plug is fouling out. The engine will run OK on the uppers or both uppers & one lower but you can get a stall if you lose a lower plug firing.

Have not noticed anything unusual. The regular black for a lower spark plug. BTW they are NGK Iridium spark plugs. Just for test I intent to put new stock ones

As a rule fuel pressure, or fuel flow issues, effect the higher speed power & runability WAY before they have any effect on the idle or stalling.

Yes. I agree with that. I just wanted to check the fuel pump and fuel pump relay just to be sure. And maybe just of curiosity, I have never tested fuel pressure on these bikes.

One other thing that W-I-L-L cause a similar stalling is the o2 sensor pig tail running too close to, or along, the R/H lower spark plug wire. The spark RFI gets induced into the o2 sensor wiring & really fouls up the idle quality & causes stalling. (make sure that the o2 sensor pig tail isn't zip tied along or near the R/H lower spark plug wire)

You maybe on to something here. As a matter of fact I have noticed that at some part, for about 8 - 10cm, they are tied together

Another thing to look for is the o2 sensor pig tail hanging down on the hot exhaust as that can also cause a stalling issue.

Will check this also

Thanks for these good directions. Will report back tomorrow

Morning 14TLC

Definitely re-route the o2 sensor pig tail away from the lower spark plug wire (just to eliminate this) -- It doesn't sound like it was done already & there was even a BMW recall on some 1150 GS twin spark bikes to do the o2 pig tail re-route .

__Re-routing o2 wire pig tail on 1150GS twin spark/

First--Unplug the o2 wire from the main harness at the right side

of the frame under the fuel tank. (you should be able to just lift rear of tank to access not totally remove it)

then--Cut all cable ties and, with the exception of the bottom clip at the rear

of the right cylinder, remove the o2 wire from any clips

holding it.

next--Carefully pull the o2 wire all the way down to the right exhaust pipe.

then--Re-route the o2 wire from the bottom clip at the rear of

the right cylinder to the retaining bracket located just under the right

side throttle body.

then--Pull the o2 wire snugly and secure it to the retaining bracket with a

cable tie.

finally--double tie strap the o2 sensor connector barrel to the frame rail. (use a tie strap on each end of connector barrel to frame). If any excess pig tail remaining double it up & tie strap to a frame rail away from spark plug wire.

After the pig tail re-route, remove fuse #5 for a good 5 minutes (or more), this clears Motronic learned adaptives, then re-install fuse #5. Then turn on ign key (do not start engine) then roll twist grip from fully closed (no choke on) to full open 3 times (this will assure that the TPS position is properly re-leaned). Then turn key off.

It is very difficult to test an 02 sensor for being active enough, you can test it for operation but not easily for correct operation. Testing off the bike is about useless unless it is just to see if it is totally dead.

After doing the o2 sensor pig tail re-route, then doing a new TPS re-learn, then road testing the bike-- if it still stalls, then (personally) I would install a new (fresh) o2 sensor. Either an expensive OEM BMW o2 sensor or a cheaper universal o2 sensor. If installing a universal o2 then DO NOT solder the wire connections as the o2 sensor gets it's reference air down through the wire strands & soldering blocks that ability.

Check your PM on this site as I sent you picture of proper o2 sensor connector placement & attachment.

Not first time.

Won't be last time.

D.R. you are beyond words.

Thanks for you contribution/participation/elucidation.

Hi dirtrider,

I re-route the O2 sensor pigtail. It was definitely not routed as you described and as I've seen on other R1150 models. Did the adaptation reset with the fuse and also TPS re-learn procedure. The bike runs good at idle as before, although with 50 -100 lower rpm than before. I was quite busy so I could not ride it today. I will give it a few good runs to see how it will behave.

I did notice something else which can be related to the stalling issue, or at least give a clue. When the engine is idling at normal operating temperature and I blip the throttle quickly, I can notice brief hesitation or misfire like an engine cut out with sudden and quick rpm drop. I'm not sure if it is actually a misfire but sounds similar. I have send you a video on PM so you can hear it also. In the last 15 seconds of the video you can hear that, especially on the last throttle blip. Before that the engine responds normally.

I asked my friend about this behavior and he said that he experienced this on numerous occasions, before and after the valve adjustment, TB sync etc.

You mentioned error codes, do you have or have access to a GS-911?

Hi dirtrider,

 

I re-route the O2 sensor pigtail. It was definitely not routed as you described and as I've seen on other R1150 models. Did the adaptation reset with the fuse and also TPS re-learn procedure. The bike runs good at idle as before, although with 50 -100 lower rpm than before. I was quite busy so I could not ride it today. I will give it a few good runs to see how it will behave.

 

I did notice something else which can be related to the stalling issue, or at least give a clue. When the engine is idling at normal operating temperature and I blip the throttle quickly, I can notice brief hesitation or misfire like an engine cut out with sudden and quick rpm drop. I'm not sure if it is actually a misfire but sounds similar. I have send you a video on PM so you can hear it also. In the last 15 seconds of the video you can hear that, especially on the last throttle blip. Before that the engine responds normally.

I asked my friend about this behavior and he said that he experienced this on numerous occasions, before and after the valve adjustment, TB sync etc.

Morning 14TLC

I can't tell much from your audio, all I have with me this weekend is a very beat up old laptop with almost no audio output. That is an awfully quick throttle opening from curb idle & something not normally encountered while riding (at quick throttle opening from curb idle the engine gets a BIG gulp of air then the fueling catches up).

See how the bike rides out then we will move on from there.

Roger brought up a good point about the GS-911, if one available that might be of some help.

@ roger 04 rt

Hi roger 04 rt . I don't have GS-911 and I don't know anyone that have in my vicinity. As I mentioned I have friend working at BMW independent car workshop and they have the dealers diagnostic system. Unfortunately that system does not have feature for collecting data while riding. Data is collected and stored in the Motronic while riding and can be downloaded. But it is encrypted data and even the BMW dealers don't have necessary tools to decode that data. This is something that is only available to the technical support at BMW's "mothership" in Germany. In any case I think that the Motronic MA 2.4 is not capable for this. Later Motronic units have these feature.

What did you have in mind? What to check or log with GS-911?

@ dirtrider.

Hi dirtrider. You are right. Can not be experienced in normal riding condition. Later boxer models don't suffer from this issue, if we can call it an issue at all. I think it is more related to early generation of FI systems. This is the first time I encountered this on oilhead. But to be honest, this is the first time I tried this on oilhead. Anyway, I will go for few rides with the bike an see what happens.

Hi dirtrider,

Just to report the current state with the bike. It seems that rerouting the O2 sensor cable solved the problem. I did not touch anything else. I'm not 100% positive at the moment because the whether is not that hot. I tried several runs with the bike on highway and in town at temperatures around 20-23 Celsius. The temperature on the RID was 5 bars maximum. Waiting for a hot day to try again, above 30 Celsius. Will report back.

Just to report back on the subject. The bike runs very well. Even on hot days. The issue is gone. So, thank you dirtrider. Rerouting the O2 sensor cable solved the issue

Just to report back on the subject. The bike runs very well. Even on hot days. The issue is gone. So, thank you dirtrider. Rerouting the O2 sensor cable solved the issue

Morning 14TLC

Thanks for the follow-up, glad it is back to running better.

I know it's recommended here to start a new thread but I like to follow up with this one here as I have had the exact issue and also resolved with the same application; rerouting the O2 sensor pigtail. I had it routed very differently when I had to split the gearbox with the engine due to a cam shaft seal leakage. Now, the idling still dropped a little, from 1200 - 900rpm but not to an engine stall. This occurs only after a restart of the engine (5mins apart) while at operating temp. As I also have the Af-xied installed, I am very hopeful after a few runs, I would gain back to normalcy. Thank you again for the elucidation. Appreciated.

On 6/22/2018 at 3:09 PM, dirtrider said:

Morning 14TLC

 

Definitely re-route the o2 sensor pig tail away from the lower spark plug wire (just to eliminate this) -- It doesn't sound like it was done already & there was even a BMW recall on some 1150 GS twin spark bikes to do the o2 pig tail re-route .

 

 

__Re-routing o2 wire pig tail on 1150GS twin spark/

 

First--Unplug the o2 wire from the main harness at the right side

of the frame under the fuel tank. (you should be able to just lift rear of tank to access not totally remove it)

 

then--Cut all cable ties and, with the exception of the bottom clip at the rear

of the right cylinder, remove the o2 wire from any clips

holding it.

 

next--Carefully pull the o2 wire all the way down to the right exhaust pipe.

 

then--Re-route the o2 wire from the bottom clip at the rear of

the right cylinder to the retaining bracket located just under the right

side throttle body.

 

then--Pull the o2 wire snugly and secure it to the retaining bracket with a

cable tie.

 

finally--double tie strap the o2 sensor connector barrel to the frame rail. (use a tie strap on each end of connector barrel to frame). If any excess pig tail remaining double it up & tie strap to a frame rail away from spark plug wire.

 

After the pig tail re-route, remove fuse #5 for a good 5 minutes (or more), this clears Motronic learned adaptives, then re-install fuse #5. Then turn on ign key (do not start engine) then roll twist grip from fully closed (no choke on) to full open 3 times (this will assure that the TPS position is properly re-leaned). Then turn key off.

 

It is very difficult to test an 02 sensor for being active enough, you can test it for operation but not easily for correct operation. Testing off the bike is about useless unless it is just to see if it is totally dead.

 

After doing the o2 sensor pig tail re-route, then doing a new TPS re-learn, then road testing the bike-- if it still stalls, then (personally) I would install a new (fresh) o2 sensor. Either an expensive OEM BMW o2 sensor or a cheaper universal o2 sensor. If installing a universal o2 then DO NOT solder the wire connections as the o2 sensor gets it's reference air down through the wire strands & soldering blocks that ability.

 

Check your PM on this site as I sent you picture of proper o2 sensor connector placement & attachment.

It will be very useful if anyone who did that, to post some photos of the procedure

Thanks

6 hours ago, johnkampol said:

It will be very useful if anyone who did that, to post some photos of the procedure

Thanks

Morning johnkampol

Check your messages on this site as I sent you a picture. 

I like to request a pic as well, if you don't mind, to verify if I have routed it in good order. Somehow there is a point (bottom (twin) clip at the rear of the right cylinder) where the O2 sensor pigtail is clipped side by side with the lower spark plug wire.