Thirsty GSA

[Bendy toy]

Yes, in my experience also, odd lambda readings are usually a symptom rather than a cause. I think in this case though I do have a faulty lambda as swapping them over moved the issue to the other cylinder. I've done about 50 miles now since I unplugged the lambdas and reset the adaptations. The bike has gotten smoother with no exhaust popping on overrun and the plugs are no longer sooty.

I had the same thing happen but soon enough I was back where I started. My old back painted coils took a long while to fully fail. IME, coils work or don't work so a pair with intermittent sparks was unexpected.

Don't swap the Lambda until you have really proved the coils. Ideally borrow some known good coils.

 

[lmg]

what issues would be manifested if the coils were fecked or on there way there? poor fuel consumption? hard to start from cold? ? ?

 

[Bendy toy]

I had poor fuel consumption but the engine seemed OK. Certainly nowhere near as bad as the failing coils would suggest. It was only when one side stopped completely that it was obvious what had been going on. Then a few miles later the other side did the same.

Seriously - sniff the coils. If they smell of hot insulation they are on their way out.

They can also be resistance tested but are VERY fiddly and gave me nothing much to work with. They get worse as they heat up so cold starting can be fine. Mine would stalling in traffic so heat has to be the issue, but an over-fuelled engine will stall anyway.

Test the bike with a pair of known good primary coils.

 

[roamer]

It looks like the lambda disconnect has balanced the cylinders,
I recall you swapped them over and the fault moved,?
No harm using injector cleaner, but with no power issues its not going to cure anything,
Now the plugs are even I would stick with your plan of running the bike,
Then fit a new o2 sensor after a week or two commuting,
Your use of evidence instead of parts bingo should see you to a permanent cost effective solution,
Roamer,

 

[bigmadstu]

Put 70 miles on the bike today during my usual commute to work. No numbers on the fuel usage but the gauge is clearly not dropping as fast. A look at the plugs afterwards suggests all is well. I will give it a couple of weeks and the get another sensor. I see the BM ones are £90 each, they are having a word. lol. They must buy the NGK ones in, quadruple the price and sell them on.

 

[Bendy toy]

£90 is cheap. I got stiffed for £160.

 

[bigmadstu]

£90 is cheap. I got stiffed for £160.

£90 was off the Motorworks website. I'm not even going to ask at the local BM dealer. New generic lambda sensors are £30 - £40. I'll have to check the specifications but I don't see why a generic sensor can't work. Will need to swap the connector over though.

 

[roamer]

Sometimes the range performance can vary on the generic ones,
as you are running two, compare the ranging in raw voltage ,
some have a slow / jerky swing voltage and cause slight hunting at cruise and idle,
Consider the original good sensor will be aged
Roamer,

 

[NZRalphy]

I had this. It was a bad O2 sensor that the bike ECU had adapted around. I replaced it and it came back to normal. Note that it will take around 100km for the ECU to adapt back to the now O2 sensor.

 

[bigmadstu]

Done 250 miles now on this tank and still showing 2 bars on the fuel gauge. Looking like it will be 300 before the the fuel warning starts flashing. Big improvement on what it was. I'm going to ditch the lambda sensors entirely as I've acquired a power commander and you have to disconnect them. Thanks for all the comments, feedback and suggestions, I'm now a fair bit forward with getting this bike sorted out.

 

[Deleted account 190920001]

Good choice getting the pcv

 

[ricalnic]

I think that's the least of the cat's problems, I suspect it will currently look like an unswept chimney, lol

LMFAO luv it, chortlin reading this in bed, "what you laughing at ?" She says. Would be lost on her.

 

[bigmadstu]

Filled up again yesterday, 28.5 liters @ 276miles. That's 43.58 mpg this time. Much better than the previous 32.
Next job will be new air filter and fit power commander. Looking at some decat headers as well as I recon the cat in my stock system is probably a bit blocked up. A good excuse I think to justify some nice new headers.

 

[lawvar]

£90 was off the Motorworks website. I'm not even going to ask at the local BM dealer. New generic lambda sensors are £30 - £40. I'll have to check the specifications but I don't see why a generic sensor can't work. Will need to swap the connector over though.

PLEASE PLEASE PLEASE
Read this before considering generic anything
I got back into (modern) biking 18 months ago and bought a Suzuki V Strom DL1000 after a couple of months I started to get a slight misfire not all the time but intermittent.
To cut a very long story short a friend diagnosed a failing coil.
Suzuki coil £70 MandP generic coil £12.50
Fitted coil all fine then BANG only working on one cylinder
Local garage diagnosed generic coil had blown the bikes ECU
When you test the coil (and I had 2) they do not perform within the Suzuki recommend parameters
New ECU £1200 managed to get one from e bay
Still in process of taking M&P to court

 

[bigmadstu]

I agree 100% there lawver, be very careful if you decide to use generic parts. In this case however it is well known that BMW use NGK lambda sensors. I looked up the NKG / NTK catalogue and they list P/N OZA630-BM1 as a direct replacement for the K25 ( R1200 ) engines. Has the right connector on it for the BMW loom. I'm not replacing my failed sensor as the soon to be fitted power commander doesn't use them. If I did get this generic sensor I'd screw it into the headers, fire up the bike and check the output voltage against the other sensor before plugging into the loom.