Hi commuynity. Its been a while for me being silent without screaming for help.
So its time again. I have a persistent and randomly appearing problem with engine cutouts. Sometimes when warm, sometimes when starting. It idles but when trying to rev more than 2000rpm it stalls.
it's no grounding, its no pump, no hall effect sensor, no ignition switch, no pump connector ( all of these checked/tested ).
I'm suspicious with the coils and the temp sensor.
After doing my studies in this forum and FB pages i did measure the secondary and primary coil terminals and also the HT Leads. 
The 3rd cylinder cable lead had triple the resistance of the other cables. Connector was corroded.


Also the coils gave the following measurements on the secondary terminals:

Coil number one (close to engine) 11.73 kΩ
Coil number two (rear, close to battery) 14.30 kΩ

The measurement were taken with the bike hot after 20km ride. My coils are the older type ones, full black. Dont know if previous owner got them changed, bike has 102.000km now.

So, could coils cause the issue shown on the video below? Thank you!

George_Pap wrote:The 3rd cylinder cable lead had triple the resistance of the other cables. Connector was corroded.

Certainly the spark plug cable terminals should not be corroded and the coil connection for it should not be corroded either. Did you clean its end terminals and the coil's terminal then test engine performance again? A replacement for that cable might be needed.

I sprayed it with WD40 Contact cleaner and measured it again but from 17 Ω dropped to 15+
Guess the coil also shows higher resistant because is the one that the faulty cable plugs into.
Thank you Laitch

I think what Laitch means is; did you clean all the green crap off the lead and from the inside of the coil post? When I first got LFB my leads were so bad that the connectors inside the spark plug caps were simply a pile of green dust; yet the bike kept running!

that doesn't sound like ignition lead - coils issue at all

more like fuel starvation ..air leaks etc

just my thoughts

Dai wrote:I think what Laitch means is; did you clean all the green crap off the lead and from the inside of the coil post? 

No i didnt do a special cleaning . Just a spraying. But intent to. Other thought as i wrote in the post subject is to replace the coils with the newer type ones. I read everywhere that the old type of coils could't stand up to this mileage of my bike. Actually is a miracle that they even operate.
Tough decisions 

charlie99 wrote:that doesn't sound like ignition lead - coils issue at all

more like fuel starvation ..air leaks etc

Charlie a week ago replaced all intake rubbers, including manifolds, upper tubes, crankcase breather hose , fuel lines and tested for leaks with success. Previously had serious air leaks.
Though i second your feeling of "fuel starvation" 
Just wondering if this could be caused by the coils.
Other suspicion is the Temp sensor due to the fact that this occurs whenever high atmosphere temps show up.
Really confused.

When's the last time the fuel filter was changed?

duck wrote:When's the last time the fuel filter was changed?

Α couple of months ago. 

..but.

The bike was sitting for almost nine years. After the mechanic installed a new but not BMW specked fuel pump without even cleaning the tank interior me myself changed the fuel filter.
After solving various problems with the engine ( all had to do with cutouts or non starting ) i also replaced the pump with a genuine BMW Bosch one, a couple of weeks after the filter change.
But did not change the filter again. At that point i cleaned the fuel tank too, because after removing the wrong pump i fount mug / debris under the pump seat.
So i m afraid that maybe the filter got some particle in it. 
i have already ordered a new one to do that change though.

I would like to report that the problem solved as i replaced (same time) coils with the new type ones, fuel injectors ( four hole type from tills.de ) and a set of NGK HT leads. K is running as a charm now, just a tad of higher fuel consumption. 
Thank you all for your precious advices.

well done ...I think the injector retro fit was a good move ... so glad you got it running far better

 did you happen to measure the old coils ? what was the result ?

cheers