Bike failed me again

Hi Shakey, assuming the running values include engine rpm and injectors switching,
slip a spark plug in a coil and lay on the engine and see if you have a spark, and is the plug wet or dry, if no spark go to the 4 coil output wires mentioned earlier for short to earth and each other tests, as continuity was ok last check,
considering the winding route of coil wiring through metal clips the short circuit code you had would be potentially worth the above tests, and visual checks,
if there is a spark and wet fouled plugs, the throttle bodies position would be a good check and response in value to twist grip, basic setting adaption,
this bearing in mind is if you have a spark, the fuel pressure at 5 bar is ok , injectors are showing a ms value ? the fuel and ignition system and sensors are running ,
it will need air and clean plugs to function, there is a possibility a dud coil shut it down and all the subsequent cranking and dismantling flooded it,
I expect you have considered the slim possibility of checking the fuel is petrol and no contamination,
see how it goes, spark yes or no first,

Good luck
 
Hi Shakey, assuming the running values include engine rpm and injectors switching,
slip a spark plug in a coil and lay on the engine and see if you have a spark, and is the plug wet or dry, if no spark go to the 4 coil output wires mentioned earlier for short to earth and each other tests, as continuity was ok last check,
considering the winding route of coil wiring through metal clips the short circuit code you had would be potentially worth the above tests, and visual checks,
if there is a spark and wet fouled plugs, the throttle bodies position would be a good check and response in value to twist grip, basic setting adaption,
this bearing in mind is if you have a spark, the fuel pressure at 5 bar is ok , injectors are showing a ms value ? the fuel and ignition system and sensors are running ,
it will need air and clean plugs to function, there is a possibility a dud coil shut it down and all the subsequent cranking and dismantling flooded it,
I expect you have considered the slim possibility of checking the fuel is petrol and no contamination,
see how it goes, spark yes or no first,

Good luck
Already done Roamer - no spark

I had to get the bike recovered in June and contaminated fuel was suspected then. The fuel system was drained and cleaned and new spark plugs were fitted.

There’s a good smell of fuel when I turn the bike over but the plugs are clean and dry.
 
… and finally, I managed to find a T12v bulb as suggested above. Across pins 3 and 2 with the ignition on, the bulb lights like a goodun. When put across pins 1 and 2, I would expect to see a pulsing light as I turn the motor over; i.e a representation of the DME trying to trigger the transistor base in the stick coil. Nada, zip, zilch, nil point.

Just for completeness, I also health checked the main and master relays. All OK.
 

Attachments

  • BFA9E59D-A622-43E9-B0B2-41418546B587.jpeg
    BFA9E59D-A622-43E9-B0B2-41418546B587.jpeg
    161.7 KB · Views: 423
Hi Shakey
you really are just at the ecu trigger to the coils , a prevention like start interlock would be visible in immobiliser or switch position for kill switch if there was an issue ,its clear that you have been thorough,
but just for the sake of being sure if you don't mind,
the wiring at the coils showing short to earth is best continuity tested with a bulb in circuit not the multimeter,as a corroded / stranded wire will appear continuous without load,
I use a 21 watt bulb with leads attached and put each cable to ground via the bulb and apply 12v, it should be bright,
you may have already done the tests as mentioned, but the individual live and switching each side should be tested for short together and short to earth,
I have often found a corroded wire the multimeter showed continuity without load, also thin wires that have collapsed insulation and shorted together just with the weight of the loom at a pressure point, which from the outside appears ok,
apology if its been covered,,
 
Interesting read but as at Post #78, the fuel pressure is at 5 Bar. I wouldn’t imagine it needs to be any higher than that.

Shakey sorry if I insit, but says this

I removed the tank and fuel pump, the voltages seem to be okay (12V when key in run position then goes to 0V, when starter button depressed voltages jumps back to 12V), fuel pump and the controller appears to be okay , but obviously not the fuel pump was seized, but did not show this.
 
Shakey sorry if I insit, but says this

I removed the tank and fuel pump, the voltages seem to be okay (12V when key in run position then goes to 0V, when starter button depressed voltages jumps back to 12V), fuel pump and the controller appears to be okay , but obviously not the fuel pump was seized, but did not show this.
I understand.

I’ve just had the left injector out and it is certainly pulsing fuel out but I have absolutely no idea if it’s enough or not. When I switch on the ignition is makes the same noises it always has done but I think that’s mostly the exhaust valve cycling.

I think I’m getting to the point where I’m just going to leave it to BMW who will pick up the bike next Monday. I would like to think that maybe they’ve seen something like this before and will have the history to fix it.
 
I understand.

I’ve just had the left injector out and it is certainly pulsing fuel out but I have absolutely no idea if it’s enough or not. When I switch on the ignition is makes the same noises it always has done but I think that’s mostly the exhaust valve cycling.

I think I’m getting to the point where I’m just going to leave it to BMW who will pick up the bike next Monday. I would like to think that maybe they’ve seen something like this before and will have the history to fix it.

Poor Shakey will be big bill again. :(
 
What’s that Dutch saying about the one who tries to get the last of the cream from the jar will get the lid on his nose? :D
 
What’s that Dutch saying about the one who tries to get the last of the cream from the jar will get the lid on his nose? :D

:beerjug: I am thinking more what they fix last time, or suppose to have fix was not the real problem, so they should not make you pay again, they already give wrong answers.
 
:beerjug: I am thinking more what they fix last time, or suppose to have fix was not the real problem, so they should not make you pay again, they already give wrong answers.

In fairness I did manage 500 ish miles in between breakdowns so they certainly fixed something.
 
… and finally, I managed to find a T12v bulb as suggested above. Across pins 3 and 2 with the ignition on, the bulb lights like a goodun. When put across pins 1 and 2, I would expect to see a pulsing light as I turn the motor over; i.e a representation of the DME trying to trigger the transistor base in the stick coil. Nada, zip, zilch, nil point.

Just for completeness, I also health checked the main and master relays. All OK.

By looking at the picture (and as you allready know), the #3 pin will provide a steady +12V voltage, and #2 a steady ground, thus the bulb will light up (as allready mentioned).

But reading signals from #2 by means of a light bulb will not work.
According to the picture, #2 is driving a transistor. This means that the output has a resistor in line, and it's resistance may be several K-ohms. In order to obtain a signal reading from such a signal, you need a scope. The puls will be a very short burst of a couple of mA only, and and the burst is so short that it may be difficult to observe even if the bulb is replaced by a LED.
 
By looking at the picture (and as you allready know), the #3 pin will provide a steady +12V voltage, and #2 a steady ground, thus the bulb will light up (as allready mentioned).

But reading signals from #2 by means of a light bulb will not work.
According to the picture, #2 is driving a transistor. This means that the output has a resistor in line, and it's resistance may be several K-ohms. In order to obtain a signal reading from such a signal, you need a scope. The puls will be a very short burst of a couple of mA only, and and the burst is so short that it may be difficult to observe even if the bulb is replaced by a LED.
Yes I wondered if the bulb was appropriate but it was all I had.
 
Fair point Knutk ref the bulb test, apologies I only had a brief look at sketch diagram from Haynes,
if the ecu and coil was un plugged the multimeter test on ohms ,
with the meter probe remaining in the signal pin on the coil plug it should read m ohms / open circuit when putting the other lead probe to engine casing earth / ground and then go to the supply pin at the coil plug,
the diagnostic evidence if it was for the date of failure does suggest a short, and everything but coil trigger has been verified as functioning, assuming the coil supply was checked under load, plugged in,
You have been thorough shakey ,I appreciate its been a journey, but there isn't much left,
in your endeavours you have erased the diagnostic data that may have been expanded beyond what the gs911 shows, so the dealer are effectively at a disadvantage,
so they are likely so spend time with manual tests to the point you have reached,
before a control unit swap it is best practice that the dealer should follow continuity and migration tests,
with timing checked , fuel injecting, power to the coils, but no spark or coil driving, the wiring tests are a must to avoid doubt and peace of mind, ,
 
Yes I wondered if the bulb was appropriate but it was all I had.

A 21Watt bulb is a good thing to use

LED takes very little current to work and can draw just enough to make it work

If you tried from The positive to frame earth through the 21 watt bulb

and then from battery positive through the bulb to that circuit earth

That would confirm both circuits can handle the required energy
 
BMW picked the bike up on Monday and are scratching their heads too. They say that they are getting a spark but it's very weak. Other than that, they've just about got to the same place as me and are about to do some checks on all ignition related wires in the loom, followed by a test of the DME.

Anybody know if a used DME can be re-programmed and used on a second bike? I know they are coded to the chassis / VIN or whatever but can they be re-used? BMW guy thinks they can't for cars but doesn't know for bikes.
 
I have fitted my ECU off my 1200 to a mates bike to test a fault and discovered his ECU was ballixed

I covered my Key in tin foil and put his near the antenna
 


Back
Top Bottom