HELP OILHEAD EXPERTS! Bike dies after running 5 minutes.

[rrfullmer]

THE BIKE: 2002 R1150RT with about 40000 miles.
THE PROBLEM: The bike will start nicely and run for about 5 minutes on choke, then run rough, then die. This happened with a cold bike in a cold garage (20-30 deg) while the bike is on the stand. Same issue if the choke was turned off after a couple minutes. It would usually restart after 10 to 15 minutes. (Thermal issue?).
WORK I DID: new coil, new spark plugs and wires, new fuel filter and internal tank lines, new external quick disconnects, new HES sensor and lines.
DIAGNOSTICS: An aftermarket error reader shows no error codes. when the engine ran rough, the Lambda voltage (O2 sensor) would oscillate, and the bike stopped. (Possibly a problem in the software transition region from using no O2 sensor to the closed loop feedback using the sensor). I replaced the O2 sensor with a used one from eBay and the Lambda sensor voltage oscillation was gone. The bike still stopped after 5 minutes. I’m out of my league.
BMW DEALER: They did a valve adjust, fuel injector cleaning and test. Fuel spray pattern looked good. They measured pump output at 2.8 bar, the lower pressure limit. New plugs were black. The dealer mechanic says that the plugs are getting spark when the problem occurs. He has ruled out electronic problems.
BMW mechanic replaced the fuel pump (new aftermarket brand) and all internal hoses. No improvement, with the pump pressure still 2.8 bar.
CURRENT STATUS: mechanic thinks the next step is to replace the fuel regulator. I’m sure he’s right, but this is very expensive at the dealer, and I’m not interested in doing it myself.
HELP NEEDED: Has anyone seen this problem and can provide me with any information or alternate directions to investigate?
Sorry for the length of the post!

 

[69zeff65]

H.e.s.

Could be the wires on the Hall Effect, Sensor. The insulation on the wires is known to break down and flake off exposing the bare wires to ground and each other. Plenty of info in these forums.

 

[20774]

Click on the View Tag Cloud at the bottom of the screen. Type "Hall Effect" into the box and search other threads about the sensor and repair.

 

[ksdcr]

He said he had a new HES installed.

Several years ago, I had a somewhat baffling issue on my R1100RS. Bike started, would move a few yards, then die. Could be restarted, and same symptom repeated.

After careful examination of the wiring harness, and some internet searching, I discovered this. The lead wires exiting under the ignition key, had separated. A small break, that would open, and then close intermittently. The cause is the BMW fastens the wiring harness too tightly at the headstock, causing them to break, probably from the handlebars being turned repeatedly.

This issue occurred at about 65,000 miles on my bike. The fix? Lots of fairing disassembly, and a sub harness removal. IIRC, the BMW sub harness was about $120., but that was 5 or six years ago.

 

[RPGR90s]

DIAGNOSTICS: An aftermarket error reader shows no error codes. when the engine ran rough, the Lambda voltage (O2 sensor) would oscillate, and the bike stopped. (Possibly a problem in the software transition region from using no O2 sensor to the closed loop feedback using the sensor). I replaced the O2 sensor with a used one from eBay and the Lambda sensor voltage oscillation was gone. The bike still stopped after 5 minutes. I’m out of my league.

The O2 sensor is supposed to oscillate the voltage. Here's a good write up on normal operation. https://www.aa1car.com/library/o2sensor.htm

That being said, make sure that the right side high tension spark lead is separated from the O2 sensor lead. BMW had a tech bulletin on this for the 2 Spark 1150's, but not sure about the single spark motors.

What can happen is that the spark signal can induce mis-readings in the O2 sensor wire and mess with the Motronic mixture settings and cause a stall.

 

[dalejohn123]

I had the same problem and solution recently.

He said he had a new HES installed.

Several years ago, I had a somewhat baffling issue on my R1100RS. Bike started, would move a few yards, then die. Could be restarted, and same symptom repeated.

After careful examination of the wiring harness, and some internet searching, I discovered this. The lead wires exiting under the ignition key, had separated. A small break, that would open, and then close intermittently. The cause is the BMW fastens the wiring harness too tightly at the headstock, causing them to break, probably from the handlebars being turned repeatedly.

This issue occurred at about 65,000 miles on my bike. The fix? Lots of fairing disassembly, and a sub harness removal. IIRC, the BMW sub harness was about $120., but that was 5 or six years ago.

 

[jrogers]

Did the dealer try running it with the fuel cap open???? Could be a vent problem.

 

[dieselyoda]

Did the dealer try running it with the fuel cap open???? Could be a vent problem.

Yeh, gotta go back to the basics, fuses/grounds/voltage.

Air filter cause of the black plugs/timing/exhaust restriction?

 

[gsaddict]

THE BIKE: 2002 R1150RT with about 40000 miles.
THE PROBLEM: The bike will start nicely and run for about 5 minutes on choke, then run rough, then die. This happened with a cold bike in a cold garage (20-30 deg) while the bike is on the stand. Same issue if the choke was turned off after a couple minutes. It would usually restart after 10 to 15 minutes. (Thermal issue?).
WORK I DID: new coil, new spark plugs and wires, new fuel filter and internal tank lines, new external quick disconnects, new HES sensor and lines.
DIAGNOSTICS: An aftermarket error reader shows no error codes. when the engine ran rough, the Lambda voltage (O2 sensor) would oscillate, and the bike stopped. (Possibly a problem in the software transition region from using no O2 sensor to the closed loop feedback using the sensor). I replaced the O2 sensor with a used one from eBay and the Lambda sensor voltage oscillation was gone. The bike still stopped after 5 minutes. I’m out of my league.
BMW DEALER: They did a valve adjust, fuel injector cleaning and test. Fuel spray pattern looked good. They measured pump output at 2.8 bar, the lower pressure limit. New plugs were black. The dealer mechanic says that the plugs are getting spark when the problem occurs. He has ruled out electronic problems.
BMW mechanic replaced the fuel pump (new aftermarket brand) and all internal hoses. No improvement, with the pump pressure still 2.8 bar.
CURRENT STATUS: mechanic thinks the next step is to replace the fuel regulator. I’m sure he’s right, but this is very expensive at the dealer, and I’m not interested in doing it myself.
HELP NEEDED: Has anyone seen this problem and can provide me with any information or alternate directions to investigate?
Sorry for the length of the post!

If the pressure is still 2.8 bar why would the regulator need replacing?? That is what sets the pressure. Std. is 3 bar.
If the plugs are black it is too much fuel.

 

[pglaves]

To me this screams engine temperature sensor. Specifically, continuing to depict the engine as cold even after it is warmed up.

 

[gsaddict]

What does the RID report for temperature?

 

[ksdcr]

rrfullmer,

Several good ideas to help you fix this. Please report back when you have success.

 

[rrfullmer]

What's next for the RT?

Riders – Thanks for the feedback. Note that I will be more than 2000 miles from the bike while it is in the hands of a trusted, but not inexpensive, BMW dealer for the next month.

Further Comments:

A rebuilt HES sensor was installed (thanks GSAddict!), and it runs well for 4 to 5 minutes without issue or error code. I’m ruling this one out.

I’ve already spliced the power lines to the handlebars where the wire fatigues due to overtightening of the cables. I found out about this problem the hard way!

I took a phone video of the real-time data from my GS911 equivalent unit during failure. The engine was in fast idle at 1600 RPM. It ran nicely for over 3 minutes, and then began to stop at 3:10 (3 minutes 10 seconds), verified by audio. The engine was dead at 3:11. Just before the engine shut down, the Motronic commands were typical, and they didn’t change. Injection duration command (2.18 msec), spark advance angle (16.88 deg), closing time (3.33 msec) and dwell angle (31.64 deg). From this, I’m ruling out the Motronic unit and the sensors feeding it as the cause of the problem.

I replaced the coil and lines. The BMW tech says we have spark, so I’m ignoring electrical problems for now. Both cylinders stop at the same time and produce a good fuel spray pattern, so I’m ruling out individual injector problems.

I have had the engine kill with the tank both open and closed. We’ll check again. The tank vent hoses may have been switched, but I can’t see how that would kill the engine. I’ll remove the charcoal cannister ASAP.

These tests happen with the engine cold. Failures occur with the choke/enrichener on. Does this give anyone ideas?

Things are pointing to the pressure regulator. But why would it cause the bike to die so regularly at 4 to 6 minutes after start? Why would the diaphragm-spring assembly be temperature dependent? Could the valve stick open??? Is there a solenoid I don’t know about?

Is anyone aware of a test to check the regulator valve on the bike before R&R? Something like running the return line into a bucket or monitoring the pump output pressure just before the bike stops?

Otherwise, I’m going to place a thousand dollar bet on the table and see if I draw an ace.

Again, thanks for all the advice. I'll keep you informed!

 

[gsaddict]

You can test the fuel system by putting the return line in a suitable container and running the bike for 1 minute.
You should get 2 litres of fuel.

More here:
https://forums.bmwmoa.org/showthrea...ystem-Diagnostic-Tool&highlight=fuel+pressure

 

[rrfullmer]

If the pressure is still 2.8 bar why would the regulator need replacing?? That is what sets the pressure. Std. is 3 bar.
If the plugs are black it is too much fuel.

The BMW mechanic has tested the pump and found the 2.8 bar. IF (big if!) the regulator spring-diaphragm is sticking open, the pressure won't build to flow through the FI. The lack of pressure might not provide a decent flow pattern and not burn completely. Am I right? Probably 50/50, but I don't have a better idea. Thanks for the question, and the HES sensor currently in the bike.

You can test the fuel system by putting the return line in a suitable container and running the bike for 1 minute.
You should get 2 litres of fuel.

Definitely a good check.

I am looking for a diagnostic test for an intermittent problem with the pressure regulator. The bike runs fine for 3 to 5 minutes, then just shuts down. I've been thinking of a pressure sensor and a data recorder, but that's just more cost! See the comment about the $1000 bet.

 

[gsaddict]

The BMW mechanic has tested the pump and found the 2.8 bar. IF (big if!) the regulator spring-diaphragm is stuck open, the pressure won't build to flow through the FI. The lack of pressure might not provide a decent flow pattern and not burn completely. Am I right? Probably 50/50, but I don't have a better idea. Thanks for the question, and the HES sensor currently in the bike.

No, not right.

If the spring/piston is stuck open you will have no fuel pressure at all.

The injectors are on the pressure side (pump output) ahead of the regulator. They see the 2.8 bar and the bike will run.
The .2 bar lower pressure will not affect engine operation except under full load at max rpm (even then doubtful)

More info: if a good pump is dead headed, it is capable of 100+ psi. There is an pressure relief on the pump itself that relives that.

Pictures of the regulator and spider

 

[DSXMachina]

You have fuel pressure, but do you have volume? If there's a way for you to disconnect the fuel line before the injectors I'd do it and watch to see whether you 'run out' of fuel or not.

 

[jagarra]

To me this screams engine temperature sensor. Specifically, continuing to depict the engine as cold even after it is warmed up.

I once had a similar problem with my Vanagon where it would choke out while driving, turned out to be the temperature sensor telling the ECU to regulate/choke the fuel injection. Had me going around in ever decreasing circles. This is the only sensor I could find that may affect the mixture Description OIL TEMPERATURE SENSOR
Qty
1
Part #
12 61 1 341 602

Is this the correct one feeding the processor?

 

[rrfullmer]

Update from the original poster

Thanks for the ideas. I've had the bike in a BMW dealer's shop since the original post being looked at by a very experienced mechanic. I have a new fuel system, which along with the diagnostics efforts are pushing $1500. I'm looking into electrical, non-ignition issues at the moment.

Again, Thanks for the advice. any and all suggestions are welcome.

The problem still exists. A summary is below:

Replaced components effecting engine running: (*MS = ****** Motor Sports)
• Repaired broken red power wire to handlebar electronics.
• Fuel Filter replaced, using beemer boneyard tubing.
• Replaced HES and pulley
• Replaced fuel quick disconnects.
• Retimed bike. Looked OK.
• New coil, plugs, plug wires.
• BG44 cleaner
• BMW code reader
• Replace O2 sensor
• Top end valve adjust, (*MS)
• fuel injection, fuel filter checkout, (*MS)
• new aftermarket fuel pump (*MS)
• BMW pressure regulator (*MS)

Data and implications just before and after engine failure:
1) No real change in temperature or other sensor inputs to trigger stop. To me this indicates the sensor data is coming correctly into the motronic and not causing the failure. This greatly reduces the Garbage in, garbage out possibility.
2) No error flags in software after failure. Implies no standard failure mode.
3) The two failures I have data for shut down at very different air and engine temperatures: 51.9C and 31.7C engine, 20C and 8.8C air. Both values are realistic in my book. This causes me to question the observation that a bad temperature sensor was causing the ECU to think the bike was still cold and they flooded out after a few minutes/miles of running.
4) According to BMW, the plug was dry on the last failure, making flooding a question in my mind. However, they and I also have seen wet plugs as well after failure.
5) Used temp sensors are on order from ebay. Let’s see!
6) FI commands consistent across failure. No fuel shutdown at this point in the software. Are there other software flag routines which shut off the engine while running?
7) What about kickstand, key switch, the old ‘FIXED?????’ power lead, ABS, other options?
8) Failure is ‘gentle’, no coughing, rough running, just a smooth shutdown of both cylinders. This implies electrical, at least to me.
9) Failure is consistent after start time; this implies possibly thermal.
10) Cannot start bike immediately after failure, but usually after 15 minutes or so. Implies thermal or flooding.
 


Case 1: BAD O2 Sensor Case 2: Replaced O2 Sensor
Oct 22 2021 Jan 18 2022
before stop after stop before stop after stop
Battery 14.00 13.59 Volts 14.08 13.67
Intake Temp 20.2 20 degC 8.8 8.8
Engine Temp 51.9 51.9 degC 31.7 31.7
Lambda O2 760.1 72.94 mV 940.95 934.92
DKP 1.94 1.94 deg? 1.62 1.62
Air Press 84.6 84.61 Kpa 84.61 84.61
RPM 1350 300 RPM 1500 400
Duration 2.05 2.37 ms 2.24 2.62
Spark Adv 14.77 2.81 deg 16.88 14.41
Close time 3.58 .94 ms 3.33 6.4
Dwell angle 28.83 14.06 deg 30.23 14.77
 

 

[RPGR90s]

I'll add my $.02 and hope it's worth more than that.

I had a similar intermittent problem on my 2004 RT. One day the bike would fire up perfectly and never stall. The next day it would crank awhile before starting and ultimately stall two min. later, as I was flipping up the kickstand.

I chased every possible scenario and replaced a ton of stuff. HES, Stick Coils, injectors, O2 sensor, air temp sensor, oil temp sensor.

I did have the O2 sensor wire routed too close to the lower right spark plug H.T. lead, so that was moved away per a BMW technical bulletin (I can't remember the number).

I have a GS911 and would take data captures and nothing ever really stood out. It would literally run perfect one day and like crap the next.

The GS911 has a TPS (Throttle Position Sensor) calibrator, checker kind of a thing. You rotate the throttle with key on and as long as the graph is in the green, it's supposed to be good. But I thought, "wait a minute. The TPS is just a variable resistor. What if the resistance is constantly changing on it's own?" I had often verified the voltage was correct (370mv I recall) at throttle close, but I had never checked the actual resistance and made sure that it was stable, whatever position it was at.

So I got out my trusty Flue DVM and sure enough, the resistance was moving all over at every position I set it. The GS911 couldn't find this. Or, maybe it can but I haven't figured it out, but I bought a new TPS, installed it and it totally solved my problem. It's the one thing I replaced that definitely solved the problem. That was over two years ago now.

So that's my $.02

RPG....