2012 R1200GSA Massively Over-fuelling

[MartinL]

Evening All,
Tale of woe with my 2012 GSA, 26K miles, mine from new. Last day of a faultless 1500 mile Scottish tour the bike was hard to start after refuelling then ran rough - part throttle mis-fire, clouds of oil smoke after start up. Pressed on gently and was OK at steady 70 on M-way but once arrived at the last night's digs discretion overcame valour and we got the train home next day and subsequently recovered the bike.
It appears the bike is massively over-fuelling to the extent that the oil was diluted and the level had risen hence the oil smoke (lots) on start up. Plugs on both sides sooty and oily, so not thinking duff injector or anything affecting one pot only. Changed the oil, cleaned the plugs (new before tour) and took a punt on a new fuel pressure regulator. Unfortunately same issue, hard to start and once running clouds of black smoke and cat red hot after a few seconds so still super rich. I then removed the complete fuel distributor and checked the return line / tank return fittings are clear which they are so no chance of back pressure from there.
Any experiences or suggestions gratefully received, I don't want to throw parts at it willy-nilly. I'm OK investing in a GS911 for diagnostics as the age of the bike makes it uneconomic to look at main dealer support. I can't see it being the temperature sensor as it behaves the same cold or hot, if the temp. sensor was duff I'd expect OK cold starting and rich when warm. I can't find any reference to a fuel pressure sensor so thinking the system relies on the pressure regulator and injector timing to achieve correct mixture.

Thoughts please??

 

[Steptoe]

Could be the TPS (throttle position sensor) . Anyone local to you with a GS911 you could plug in ? .., and you did fill with petrol and not diesel ?

 

[MartinL]

I did wonder about that. Might try unplugging to see if it defaults to a pre-set map. I also presume you can check it out with a digital multi-meter e.g. rising resistance? My BMW pirate CD manual has no diagnostic or test data just replacement instructions for everything. Unfortunately there is a lot of BS & misinformation on here about the injection system too. I don't personally know anyone with a GS911 but as I said don't mind investing given the cost would only be equivalent to a short spell at the main dealers!

 

[squibb34]

Sorry to say it sounds exactly like diesel fuel contamination to me - if it's say 50/50 the car/bike will run, extremely rough & the cat will glow red hot.

Happened with my wife's new car once, when the dealer team wrong filled it before collection. It was OK initially, but after a few miles we had to turn tail & returned, ultimately rejecting the car as the trader wouldn't underwrite the potential cat/lambda damage.

 

[MartinL]

If it's diesel contamination then there's a lot of people in Falkirk with the same issue as I definitely didn't misfuel. I did have the same thought though as it happened immediately after refuelling. I don't think that would really explain the oil dilution and rising level. I drained about 1.25 litres too much out of it. Also ran about 120 Miles at steady motorway speed a no diesel smell. Cheers.

 

[stever1]

You’ve put diesel in it. It washes past the piston rings. What brand of fuel did you fill with. Some of them can be confusing at 5he pump. IE. Premium unleaded pump is branded similar to premium derv. how many litres did you put in.

 

[MartinL]

No I haven't, unless the garage have filled their tanks incorrectly. For what it's worth I always run on boggo unleaded and I'm not colour blind; I also start with the nozzle all the way in, you'll find diesel pump nozzles are bigger than petrol. It's actual quite hard to misfuel a modern petrol vehicle for that reason, you have to try quite hard

I should point out that when it was warm and it's "throat cleared" it would idle OK but would die when throttle just off idle, a few blips and get through that and it ran steady on the motorway on a wider throttle opening. Makes me think Steptoe has point about the TPS; I'll bring some suitrable test leads home tomorrow and check the voltage range.

 

[MikeO]

Check both throttle cables are correctly seated - your symptoms sound a lot like the ones you get from a 'shouldered' throttle cable.

Full disclosure - I've never owned a bike like yours, but the sudden onset is suspiciously like the problem nearly everyone has experienced one time on another with an R11XX...

 

[TLSgazza]

You’ve put diesel in it. It washes past the piston rings. What brand of fuel did you fill with. Some of them can be confusing at 5he pump. IE. Premium unleaded pump is branded similar to premium derv. how many litres did you put in.

I think you may be right. Nearly picked up the premium diesel pump myself a couple of weeks back. It looked almost the same as the premium petrol pump.
I'd suggest draining the tank completely. putting in fresh fuel. Pump some through the fuel pump and see how it after that.
I have had a couple of friends do it and we're adamant that they didn't put diesel in, they had easily done.
Swallow your pride and try it. Much simpler than all the other things you are suspecting.

 

[stever1]

No I haven't, unless the garage have filled their tanks incorrectly. For what it's worth I always run on boggo unleaded and I'm not colour blind; I also start with the nozzle all the way in, you'll find diesel pump nozzles are bigger than petrol. It's actual quite hard to misfuel a modern petrol vehicle for that reason, you have to try quite hard

I should point out that when it was warm and it's "throat cleared" it would idle OK but would die when throttle just off idle, a few blips and get through that and it ran steady on the motorway on a wider throttle opening. Makes me think Steptoe has point about the TPS; I'll bring some suitrable test leads home tomorrow and check the voltage range.

The main give away clue here is the fact that fuel has washed past the piston rings. Derv will, petrol less so.
All the symptoms seem to point to wrong fuelling.

 

[Pukmeister]

When my 2009 GSA had an overfuelling problem and rough idle/stalling, I discovered a faulty Lambda and a failed RH lower stick coil.

 

[knutk]

My humble comments:

As for filling Diesel in a petrol engine, I have never heard of a case where the engine did not stop running after a short while...

I assume that the possibility of the throttlecables playing a trick has been eliminated (as suggested in a post above)

An ECU (BMS K in the BMW world) issue really needs a diagnostic readout. Changing parts on pure 'belive' is just too expensive.

If there are no visible warnings, this indicates that there are no sensors that have failed completely.

There are two type of components that may cause a major influence on the fueling, O2 sensors and the throttle position sensor.

As there are two O2 sensors, the chance of both of them fails simultaneously is fare fetched, hence an inspection of sparkplugs may give a clue.

There is only one throttle position potmeter. If a cable brakes, the potmeter may throw a warning or trigger an internal faultcode, but if it for some reason just offers a faulty reading, this may cause a fueling being too rich or too lean.

The TPS is self-learning when it comes to calibration, thus, as long as the ECU senses a variable voltage between low and high (closed to fully open), the ECU will consider the lowest reading as throttle idle position and highest value as WOT.

On the other hand, if for instance the ground cable to the potmeter is broken/disconnected for some reason, the reading from the TPS will always be for maximum fueling.
In this case, the O2 sensors will sense a too rich mixture, and will try to lean the fuel. But there is a limit to the adjustment range that may be imposed by the O2 sensors, so the engine will probably run too rich, but it will run.... But then again, then there ought to be some sort of warning...

So... if this was my problem, I would start by getting hold of some diagnostic equipment and conduct a fault code readout and then use it to monitor live values for the O2 sensors and the TPS voltage. (being a pre-13 bike, a used, yellow GS 911 will work just fine).

I'm not sure if the pre-13 bikes will offer the adaptive fuel trim values, but if these values indicates that the ECU is trying to trim down the fueling (based on O2 sensor feedback), this also means that the ECU is fully functioning, but some error causes it to richen the fueling way too rich.

The ECU controls the amount of fuel to the engine based on a timed opening and closing of the fuel nozzles. To be accurate, the system needs a steady fuel prssure.

If the fuelpump regulator circuit fails and the fuelpump deliver a too high fuel pressure, this may also cause the engine to run too rich. And again, the O2 sensors will try to reduce the fueling, and again, they have a limited capability.

I put my 2c on the TPS sensor or it's wiring, or a fuelpump issue...

 

[MartinL]

Thanks for all your input gents, I really appreciate the help. Diagnosis completed, I have managed to put 18.54 litres of diesel in it. What's incredible is that I subsequently rode 181 miles two up with luggage, no dramas on a 56% diesel mix! Says something for the GS ignition system and adaptive fuelling Both Mrs L. and I were adamant the green nozzle was selected but the receipt says otherwise.

Looking at the service station on Google they have a quad pump layout - unleaded diesel diesel premium and to be fair the tops of the pumps have signage but.....every nozzle has those plastic advertising thingys on and they are all green

So full marks to the misfuelling camp and be careful out there!

I will let you know how I get on after a flush and oil change.

Cheers.

 

[knutk]

Thank you very much for your honest feedback .

And I have now heard of a bike that managed to run, even with more than 50% of diesel in the fuel.

I find this highly impressive, and kudos to BMW for installing knock-sensors in the engine and that they actually manage to handle such an awfull mix of fuel

 

[Gelandestrasse]

A lesson for us all!

 

[stever1]

Thanks for all your input gents, I really appreciate the help. Diagnosis completed, I have managed to put 18.54 litres of diesel in it. What's incredible is that I subsequently rode 181 miles two up with luggage, no dramas on a 56% diesel mix! Says something for the GS ignition system and adaptive fuelling Both Mrs L. and I were adamant the green nozzle was selected but the receipt says otherwise.

Looking at the service station on Google they have a quad pump layout - unleaded diesel diesel premium and to be fair the tops of the pumps have signage but.....every nozzle has those plastic advertising thingys on and they are all green

So full marks to the misfuelling camp and be careful out there!

I will let you know how I get on after a flush and oil change.

Cheers.

My pal went from Dumfries to Castleside , about 85 miles on a misfuelled f800. When it finally gave up it had totalled the engine. Took out 6 litres of oil/ derv mix out of the sump. however. He had about an 85% derv mix after fuelling.

 

[Mistacat]

You may find that it has not done your lambda sensors any favour's.
Best to check them with a GS911 after this.

 

[MartinL]

Here's my two old tractors. They both run on diesel but the English one likes it much better

Bike seems fine with a galllon of fresh unleaded in it. Cat ran a bit hot for a minute until the diesel soot burnt off but all seems settled now. I'll give it oil and filter change no.2 this weekend then just keep a close eye on fuel and oil consumption until I have a bit of confidence there's no long term damage. I'll let you know either way.

If anyone needs a good used fuel pressure regulator or 15 litres of lightly shop soiled petrol let me Know?

 

[Steptoe]

.., and you did fill with petrol and not diesel

First reply to your post

 

[MWH]

At least it's an easy fix. Where are you in the country, someone near you may have a gs911/ Motoscan and plug it in for you to see if there is anything else.