Computer says NO (stalling GS)

[MattSwain]

Had a frustrating afternoon at the dealers this afternoon with my 08 1200GS. It's started cutting out on downchanges (with the clutch in) and it strikes me as kinda dangerous if it does it in the wrong circumstances. It first did it a week or so back, 4 times in one 200 mile ride in fact. Basically if you change down through the gears in such a way that the engine is basically idling rather than ticking over it seems to want to or actually does cut out. If you blip the throttle or change down higher in the rev range, it's fine. I've been effectively riding around the problem since then although it has caught me out twice more.

Anyone bright ideas? The bike is going to have to be sold because it's dangerous if the fault isn't found.

Unsurprisingly the all-knowing diagnostic machine said there's nothing wrong with it. It's going back on Friday for round 2.

 

[Schtum]

When my old '04 bike started doing that, it was a failed lambda sensor.

 

[MattSwain]

Must confess I didn't know a lambda sensor from my elbow when you mentioned it, but a quick look on wiki (some of oxygen sensor for anyone else as clueless as me who doesn't want to admit it!) and it does sound plausible.

 

[Schtum]

Must confess I didn't know a lambda sensor from my elbow when you mentioned it, but a quick look on wiki (some of oxygen sensor for anyone else as clueless as me who doesn't want to admit it!) and it does sound plausible.

Yes - sometimes known as o2 sensors. They're the things that look a bit like spark plugs on each exhaust pipe. When the bike's running in closed-loop mode, they measure the oxygen content of the exhaust gases and thereby modify the mixture.

 

[MattSwain]

The one other thing I will add is that this is only happening through the downchanges. The bike will sit and idle all day long either with the clutch in or when in neutral. If you get to a stop with the bike running, it will continue to run.

It's done 8k miles and was serviced on schedule about 1500 miles ago.

 

[Jaq]

? A similar thing happening with the 800gs's and I had it happen with my 650 twin......
It turned out that it was due to me using the throttle slightly when starting the engine and the on board computer thinking that baseline idle was higher than it should be.....now start the bike just on the button and not touching the throttle (a bad habit from previous bike)....no more cutting out since....touch wood.....
I don't know what happened with the others who had initial probs....
Probably totally irrelevant to your problem, but who knows?
Good luck with getting it sorted......

 

[MattSwain]

I've always started mine with just the starter button so don't think that applies to me, but thanks for the suggestion anyway.

 

[wadham]

I have had this on 2 boxer 1200 engines. A GS1200 and an RT1200.

You approach a roundabout or bend at speed and brake, close throttle, pull clutch in and the engine has cut out. You end up grinding on the starter motor to get it running before that HGV wipes you out or you fall over on a hairpin bend. Other times the engine splutters and gathers itself from very low revs. This does not happen everytime so is hard to detect on a short test ride by a garage.

This is a dangerous fault that BMW have not yet as far as I know dealt with. One dealer could not diagnose the fault on the computer so the manager rode it home. It happened to him and it was reported to BMW who would not authorise exploratory work - eg changing parts until the fault was fixed - so that was that.

I sold both of them before it was fixed for other reasons.

I have just bought a new 1200GSA and if this happens again they will get it returned as not fit for purpose right away and supply me with one that works.

We need to get BMW to deal with this so if you have current evidence of this fault please write to BMW and your dealer and if no joy lets see what the press can do.

 

[zoltan]

You are not alone , I had a similar issue see here:

http://www.ukgser.com/forums/showthread.php?t=183993

 

[Pukmeister]

The NGK plugs for a 1200 are DCPR8EKC, they cost £3.49 each plus P&P from sparkplugs.co.uk

Might be worth buying a new set and seeing how you get on?

Also worthy of note, I recently had to fit a new secondary coil due to it splitting through corrosion of the internal transformer laminations. Maybe you could pull your lower coils and take a look at their condition?

 

[Pukmeister]

When my old '04 bike started doing that, it was a failed lambda sensor.

If you had a GS911 you could check the "real-time values" of the Lambda probes to see if one had a faulty output.

Might be a few units available to borrow from people soon for diagnostics after the group buy.

 

[Steve E]

I had similar problems that were diagnosed as a broken cam shaft position sensor. Sensor was changed and all has been good since.

Get your dealer to the sensor.
Your bike is still in warranty so why worry too much.

Steve

 

[Sgt Bilco]

Blip the throttle on downchanges

I`ve had this happen a couple of times on the 1200 and it also happens on the 1100 on occasion. It`s not something I worry about, because I rie round the issue.

I`ve got a feeling that it`s only likely to happen if you change down a couple of gears with the clutch in and engine at idle which to be honest, I rarely do. Blipping the throttle on downshifts sorts it out so why not do this?

Keep onto your dealer if you think it`s an issue but I`m sure it`s a foible of the boxer in the conditions I`ve described.

Wadham, you`ll be very lucky with trying the "fit for purpose card". The bike is obviously fit for purpose and all BuMW have to do is cure the fault on your bike if indeed there is one. Oh, and the press won`t print anything because who do you think is more important?. A disgruntled customer or a paying advertiser

 

[MattSwain]

Thanks for all of the suggestions folks. I don't know if it helps or not knowing that others have experienced the same given the mixed outcomes that people have had.

I can see it being a fruitless visit to the dealer on Friday because I've had a few goes at inducing a stall today and of course it won't do it. Will try again tomorrow.

One thing I'm not prepared to do is ignore it. If it had only happened once or twice rolling up to traffic lights then maybe I could write it off as a quirk (a quirk that any £500 Honda wouldn't have - it's kind of basic, clutch in should equal impossible to stall) but the fact is that it first did it on a shift between 6th and 5th at speed and on a different day on a different road, the consequences could have been real bad. That was the first of 4 stalls in one day and 2 in the fortnight since even though I've been trying to ride around the problem.

 

[Sgt Bilco]

Thanks for all of the suggestions folks. I don't know if it helps or not knowing that others have experienced the same given the mixed outcomes that people have had.

I can see it being a fruitless visit to the dealer on Friday because I've had a few goes at inducing a stall today and of course it won't do it. Will try again tomorrow.

One thing I'm not prepared to do is ignore it. If it had only happened once or twice rolling up to traffic lights then maybe I could write it off as a quirk (a quirk that any £500 Honda wouldn't have - it's kind of basic, clutch in should equal impossible to stall) but the fact is that it first did it on a shift between 6th and 5th at speed and on a different day on a different road, the consequences could have been real bad. That was the first of 4 stalls in one day and 2 in the fortnight since even though I've been trying to ride around the problem.

Matt

If it cut out in a high ger, you would seem to have a bigger problem than I`ve suggested. I`d be into the dealer and don`t take no for an answer

Do you blip the throttle on downshifts?

 

[MattSwain]

I've started blipping the throttle on downshifts as that's kinda become my workaround. It's not something that I've always done though.

 

[Paul90]

With most fuel injection systems if you close the throttle in say 6th gear with the revs above say 3000 then the computer will shut of the fuel completely.

Once the revs drop to say 1500 the fuel comes in again to keep the engine ticking over.

I'd suspect a weak spark / coil or perhaps throttle sync slightly off such that sometimes it doesn't quite catch in time to prevent a stall. Might also be fuel related pump / FPC / injector.

With an intermittent fault like this you could easily spend the value of a decent bike on labour charges while some f**kwit dicks about waiting for the computer to tell him what to change.

I've heard tails of labour charges over £1000 before a dealer found a faulty coil.

Good luck.

Paul

 

[smartbear]

greedy barstewards

iv had the same prob with my gs,dealer couldnt find any thing wrong-no fault codes
and then tried to charge me for the privilage it was still under warranty at the time & i havent been back their since and now service it myself out of spite.

 

[harry]

I rode around this stalling on down changes for the last 1000 miles or so,

however Sunday past it was doing it very frequently and then expired

completely. I was left stranded in heavy traffic with no kerb and a high grass

bank. The traffic was passing 2 feet away at speed, I could have cheerfully

killed anybody connected with selling, or manufacturing BMW motorcycles.

It was the old FPC of course.

This is a most dangerous fault, the bike has been ridden for 150 miles today

and has not stalled once.

I shall think long and hard before buying another BMW. This is my 6th GS and

4th GS12.

 

[Beemerman59]

Everyones experience is different. Mine did this a few times and when it did was from third to second and each time the rear wheel locked up and the bike slewed to a halt. The bike (1200GSA) has since had a 6K service and having put another 500 miles on since then I have not had a repeat. Mind you I am now tending to blip the throttle just trying to get a smooth downchange through the box - my god it's clunky!!