Replaced Motronic, bike would not start, timing half turn wrong

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'99 1100 GS here, ~200 kkms, number of repairs in the last 3 years

I have now gone through a "Hall sensor failure" saga with 4 sensor replacements which has turned out to be Motronic ECU failure and is now writing its 2nd chapter: "The WTF of the Engine timing"

So, I have replaced Motronic with a 2nd hand used one and now my bike would not start, I have diagnosed that timing is almost half way late (!). When key on, turning the rear wheel in 5th, turning the engine, the pump would not whine at TDC, but rather ~half turn (about 160° later). I have then double checked the hall sensor installed correctly, and found no obvious errors - the cup and the pulley fit as they should. The sensor is new.
The culprit: when starter turns the enigne, there is spark, there is fuel from injectors, it wouldn't start, but would loudly explode out of exhaust here and then


The question:
If everything is assembled correctly, sensor working fine and everything else is ok with the bike, is it possible I have just bought a faulty 2nd hand Motronic, that consistently sends wrong (half turn late) signals to the pump, injectors and coil with correct output from the Hall sensor?

This doesn't seem plausible to me, but I have now triple-checked I have installed Hall sensor correctly ... but I *am a DIY wrenching idiot.

Please, give me some wild guesses to help me think this out.

Thank you.
Daniel

 

[MattW]

My gut feeling is that you *must* have fitted the crankshaft rotor incorrectly (the 'cup' behind the crankshaft pulley with the cutout to trigger the hall sensor) - it's the only thing that could shift the ignition timing in the way you describe.

 

[Beebop]

Is it possible that the top and bottom HES are swapped ?

 

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The shocking thing is that I have not touched HES from the last time I have ridden my bike for 5kms from the workshop to home: the evening before the morning the last time my bike would not start "HES failure" way.
I.E: HES shouldn't be the problem methinks (??) ...

@MattW: I know, but WTF?? Here is the pic of how exactly the thing looked like when I have opened it up:

In my book this spells OK. The shaft was few degrees before TDC due to the force I used to undo the nut. You can see the hole on the cup: this should be just a few degrees before the upper sensor would have sent the signal.

@beebop: I was thinking the same, but then it is not 180° late, but somewhat earlier.
This is the exact position of the engine when the pump whined:




I will measure the output from the hall sensor with a LED on the connector. That would tell me the truth about my installation skills.
I presume it is the upper sensor that should trigger pump whine?

 

[cookie]

what about it being the wrong motronic ECU?

 

[Steptoe]

what about it being the wrong motronic ECU?

That was also my thinking.

As an example, you fit a 2000 1150 motronic to a 2002 bike and all sorts of weird shit happens. Yet everything else is the same

 

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Yes, possible.

This is my (toasted) original



And this is the cheap-o replacement off zi german ebäy

(link to the item, it says "tested, would run") You CAN laugh at the price.


I did do internets research and the 1 341 925 does show up as a motronic being used in many R's since fuel injaculation. Basically it is supposed to be the same for 1100 RT, R and GS. Supposedly.

My dealer also confirmed that 1 341 925 is indeed the part number of the same device (as 1 342 747) since '97 onward.
I will call another one just now to re-re-confirm.
[edit: just called the nice guy from the other dealer and confirmed this is indeed the same device, yet other catalogue number]

All things considered: a wrong motronic would send everything ok, just wrong timing?

 

[DrFarkoff]

In this picture the little lug that should be in the groove on the crank looks flat??

it is the two short lines pointing at your thumb

I don;t know how much your crank moved undoing the bolt? but the crank groove has nearly turned a whole revolution

But if you only moved the crank a little? Maybe less than a quarter turn? Then it would be approximately 180 degrees out of place?????

 

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The lug does look flat, but it isnt. It is a bad picture.
[edit 2: on the first picture you can see the cut in the shaft under the cup. so no miss-alignment of the cup to shaft]

I have done the mistake of flattening the lug a few months ago, so I COULD make that mistake again. But I haven't this time. I have manually bent the lug back to "normal" and the thing worked OK.

The second picture was made AFTER I removed the crank block from above the starter and moved the rear wheel until the pump went whine.

I use an allen key to block the engine from turning and as it doesn't fit perfectly the thing rotates for a degree or two when (un)tigthening the front bolt.

 

[Ian J Hartley]

Yes, possible.

This is my (toasted) original



And this is the cheap-o replacement off zi german ebäy

(link to the item, it says "tested, would run") You CAN laugh at the price.


I did do internets research and the 1 341 925 does show up as a motronic being used in many R's since fuel injaculation. Basically it is supposed to be the same for 1100 RT, R and GS. Supposedly.

My dealer also confirmed that 1 341 925 is indeed the part number of the same device (as 1 342 747) since '97 onward.
I will call another one just now to re-re-confirm.
[edit: just called the nice guy from the other dealer and confirmed this is indeed the same device, yet other catalogue number]

All things considered: a wrong motronic would send everything ok, just wrong timing?

From your photo that looks very much a 1 341 935 and not 1 341 925 as stated in your text. Difficult to tell with the 3 partly obscured, but what is visible definitely looks like a 3 to me.

Ian

 

[Ian J Hartley]

Forget my last! I've just seen a picture of the 1 341 925 with the writing intact, and the font used for number 2 could easily be confused with a 3, with that much of the numeral obscured.

The text says that model used on R1100RS.

Sorry to throw unnecessary confusion in.

Ian

 

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Don't worry and thank you Ian. In this situation any help is welcome!

We will all be appalled by the simplicity and obscurity of the error on the end, I promise.

 

[Ian J Hartley]

If the only thing you have changed since the bike was running last is the motronic.

Then have you checked the bike motronic connector to make sure you haven't pushed one of the sockets back.

With power off gently apply a small amount of pressure to each of the contacts in the plug. They should remain seated, if any move back, then that could be your problem.

Ian

 

[Black Rooster]

can you borrow a known working ECU to swap in , or swap your ECU into a working bike, check to see if the bought one has been opened they used to chip them

 

[FotisI]

Don't worry and thank you Ian. In this situation any help is welcome!

We will all be appalled by the simplicity and obscurity of the error on the end, I promise.

From where did you buy the hall sensors plate?

 

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Dan Cata, Advrider.com
He is very nice and helpful man. The sensor plate you will outlast earth.

http://advrider.com/forums/showthread.php?t=862122

 

[topcat2006]

Have you soldered the wires onto the original connector correctly?

 

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heh, yes, soldered multiple times. The bike has been in the garage, have lost all hopes for it to run except maybe as parts I had no time to touch it and was taken to a friend ex-bmw service guy for his afternoon pleasures. Await to see if he comes up with anything.