Engineen turns off all of sudden at idle status

[sikim7]

This is the first time I post,
This is the very good forum so I can get lots of information,
actually in Korea there are not many people riding R1150R.

I sold out my preowned 2001 R1150R and bought another 2003 Rockster 20,000 miles, abs.

By the way this rockster has a problem,
In normal speed between 75 ~ 90 miles/h, I feel something pulling back the bike and rpm is down a little bit,
and a couple of seconds later it became normal, it happens with repeat.

And during idle, when I pulling the brake lever ( then I can hear the servo turning on sound) the idling rpm drop down from
1100 rpm to 900, 800 and then I disengage the brake lever then the rpm goes to normal,
sometimes during I pulling the brake lever the engineen turns off.

Does anyone can advice to me ?

[riceburner]

Hi Sikim, welcome.

The only thing I can think of is that maybe the alternator belt is loose - thus the battery is not being charged very well and when you use the brakes, the extra power required by the ABS system is removing electrical power from the engine management systems.

May not be the cause - but it's the only thing I can think of.

[sikim7]

Hi Sikim, welcome.

The only thing I can think of is that maybe the alternator belt is loose - thus the battery is not being charged very well and when you use the brakes, the extra power required by the ABS system is removing electrical power from the engine management systems.

May not be the cause - but it's the only thing I can think of.

Thank you for your kind advice.
I also thought of it so I looked into the belt yesterday but it wasn't loose, however the condition of belt wasn't good so
today I order a belt and it will be delivered tomorrow.
I will change the belt and adjust proper tension and do test ride.
Hope this is the only reason for the bad condition.

I will update after test ride.

[MikeCam]

There was a problem with the 2001-2003 bikes (have never heard it to be for 2004 or for Rockster) wherein the Motronic cut fuel delivery when the throttle was cut. This caused bikes to stall from fuel starvation. Unfortunately, I do not recall the solution. Might be related to TPS voltage settings, might be a re-flash of the EMU is required. Might be a broken, pinched, shorted wire somewhere, esp in the coil system.

[sikim7]

Yesterday, I changed the bad fan belt and test ride again,
However the failure symtom is the same.

I searched the forum and find similar case with me.
There is two possible causes,
One is a failure of oxygen sensor,
the other is a failure of ignition coil.

Today I will check with the oxygen sensor - it is easy - and if it is fail then I will order the sensor and the ignition coil as well.
Otherwise the sensor is good, then I will order only the coil - I will change the coil anyway.

The delivery will be taking more than two weeks cause I live in Korea.
I will update after change the faulty parts.

Thanks all,

[taosports]

I had similar symptoms. I'd get flat spots in acceleration in the upper gears and it occasionally died as I'd let off the throttle coming to a stop. Replaced the air filter which was pretty filthy and the problem was solved. Poor bike was just starving for air!

[sweatmark]

Good point about the air cleaner. Full tune-up process would ensure best power output to fight the electrical system load due to the ABS pump & servos.

Has anyone here experienced failure -whole or part- of the ABS system? What symptoms would be evident? Anything that would resemble the problems described here by sikim7 ?

I'm still working on a solution to the ABS system complications...

[sikim7]

That was one of the my cuoriosity however it wasn't the main cause for current my bike.
I had changed to K&N air filter and test it. but the symtoms was the same.
During yesterday test I discovered that the engineen is suddenly dead and alive again repeatablily in very short time - in my measure it happens in 0.1 seconds.
So I do curious much more to the ignition coil, it feels like electric leakage.

I will update after change the coil.

[cone]

You could also check the Hall Sensor & plate. a Faulty one could lead to the engine cutting out and diagnostic equipment can't always pick the problem up.

[sikim7]

I found this;

"allanj255 wrote:
Found the recall

Models: BMW R Model Motorcycle Year: 2003
Number Potentially Involved: 7,000
Dates of Manufacture: December 2002 – August 2003

Defect: On certain motorcycles (Opposed Twins w/Two-Spark Ignition), the electrical wiring for the oxygen sensor and the ignition lead for the right-hand secondary spark plug have a parallel routing over part of their installation path. The close proximity of these cables may allow the signal from the ignition lead to interfere with the signal from the oxygen sensor wiring. As a result, engine hesitation or misfiring could occur, which could result in a crash.

Remedy: Dealers will re-route the electrical wiring to the oxygen sensor. The manufacturer has reported that owner notification is expected to begin during December 2003. Owners may contact BMW at 1-800-831-1117 , Option #4. "


So I did re-route the oxyen sensor cable then the problems has been disappeared.

Thank you everybody who gave me the advice.

[boxermania]

Mike Cam +1 Bravo......