Intermittent Stalling + Idle Hunting Problem

gsbiker

gsbiker

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Hello,

I'm just putting the feelers out to glean some info on this problem. I've owned my GSA new since end of 2008. I've removed the cat, put performance air filter on along with a Power Commander + custom map. Power Commander was the last upgrade some 2 years ago. 4x months after having it fitted I managed to capture on film the bike hunting at idle (I may infact upload this video to youtube) after a very short stop along a ride. At the end of that ride the bike stalls couple of times when I stop and park up. If I let the bike cool for 10min or so and start the bike up again, so long as the bike doesnt hunt at idle I get no problems thereafter. Only seems to happen when the bike starts up and hunts at idle (idle jolting up and down rather than steady RPM) after or during a run when up to temperature. This has been the story ever since. It has been completely intermittent so hard to locate fault. Thought it was a glitch at first so I ignored it. Some 2 years on and it's getting worse.

On Saturday I must have ridden for about 40min then I stopped for 2min. The bike then started up hunting. I rode off in that condition and I was having difficulty keep the bike from stalling when in traffic and infact it did stall a few times. Riding faster doesnt seem to effect the bike when it's having this problem, only at idle. I managed to get the bike in this condition and show BMW who now have the bike. But here lies the problem. They want the bike back to stock. I've agreed as there was no choice really If I wanted BMW's help and they will be changing exhaust and airfilter and unplugging the Power Commander. Because I upgraded these parts months apart from each other, I'm sure my parts are not the causing the problem, but I don't know.

So my question is, has anyone had a similar problem to mine? Did you find the cause? What was it?

Thanks
 
My 2008 with 40K miles (Akra exhaust no PC or remap) did strange things when a primary coil was failing. The other coil followed very soon after.

I took out the idle stepper motors but all seemed fine. For a while it seemed to be better but eventually the coil completely packed up making diagnosis easier. Both of my coils showed signs of corrosion on the sides.

The O2 sensor on the missfiring side got badly sooted up so it might be worth making sure both are a healthy colour.
 
Deleted account 181015003 said:
Plug in a GS911 and see if there are any error codes

Sent from my SM-N9005 using Tapatalk
Click to expand...

BMW told me they have to put my bike back to stock (includes buying a new paper air filter, which is annoying) for the purpose of getting correct error codes (if any can be found). My performance air filter, decat exhaust and Power Commander prevented further investigation at this stage! #annoyed
 
gsbiker said:
BMW told me they have to put my bike back to stock (includes buying a new paper air filter, which is annoying) for the purpose of getting correct error codes (if any can be found). My performance air filter, decat exhaust and Power Commander prevented further investigation at this stage! #annoyed
Click to expand...

The dealer has all the fancy diagnostic equipment that's supposed to make GS-911 look like a toy but they cant do anything with aftermarket parts fitted? Funnily enough BMW already sell Akraprovic exhausts and other goodies.

Checking coils, O2 sensors, etc the taking off the PC to get baseline error codes isn't rocket science for a mechanic. It sounds like an excuse for a nice little earner for the BMW dealer. If they have not yet started work, take the bike back and go to an independent.
 
Got my bike back because the cost of putting bike back to standard was much higher than I thought. I may have to go back but for now I will visit the business who fitted the Power Commander to see if it's faulty.

Bike cut out again tonight coming home through my city from dealer. Last stretch and I opened the bike up on a slip road for about 1min. When I stopped at the junction the bike cut out again Arrrr! So it's not taking much to get this to fault - just a bit of faster riding - which puts the temp up - and it can fail.

BMW told me that they beleive the fault is with the Power Commander because the exhaust sensors have been disconnected whereas one of their mechanics has a Power Commander with exhaust sensors fitted. So I don't know why my bike was setup with exhaust sensors disconnected when other GS's are connected? Anyways that doest explain why my bike is stalling more frequently these days.
 
When mine started doing this it was because one coil was missfiring. This led to that side running rich (I'll spare my theories as to why). With no O2 sensors that's less likely but a wonky coil will cause it to stall.

Check the engine temperature sensors if ECU thinks the engine is cold it will run rich as in cold start. Excess carbon affects the spark quality. The O2 sensors (or blank plugs if no sensors) should be pale grey. If black this suggests rich running. If pale grey its running weak.

Also check the crank position sensor. On some engines they will be fine when cold but fail when hot so the ECU thinks the engine has stalled and cuts the fuel.
 
Bendy toy said:
When mine started doing this it was because one coil was missfiring. This led to that side running rich (I'll spare my theories as to why). With no O2 sensors that's less likely but a wonky coil will cause it to stall.

Check the engine temperature sensors if ECU thinks the engine is cold it will run rich as in cold start. Excess carbon affects the spark quality. The O2 sensors (or blank plugs if no sensors) should be pale grey. If black this suggests rich running. If pale grey its running weak.

Also check the crank position sensor. On some engines they will be fine when cold but fail when hot so the ECU thinks the engine has stalled and cuts the fuel.
Click to expand...

I had it serviced recently and had the Iridium plugs changed back to standard plugs but the bike still getting worse. The plugs apparently were quite sooted up and they were only on the bike 2 years, probably done less that 6000 miles on them. Didn't thinkning much of it at the time or take the old plugs home because I thought the problem were the plugs.

The bike always fails in this way when up to temperature and never before. When riding and pulling in the clutch the revs drop back to idle but dips below 1050rpm before it stabilises. Wondering if it dips too low when hot and then can't recover and stalls? I'm travelling to Tim Blakemore racing. Bristol on Tuesday to have the power commander checked out as it could be that thats faulty.

Anyway, tried to remove the engine tray today to spray up in under the engine with ACF50 when I found one of the bolts all chewed up (smallest Hex bolt). So I couldnt remove the tray. BMW have done this cause they are the only ones who removes the tray for an oil change. Will have to speak to them about this. Hopefully it can be removed with mole grips or something but no one mentioned it to me when I picked the bike up!!!!!

 
hi
i have a gsa 08 plate, the stalling problem happens to me ,not all the time could be 1 out of 10 rides but annoying and very dangerous. last time it stalled i was turning right with oncoming traffic.
the symptoms i get , when starting it runs like its on one cylinder untill it warms up. when riding i blip the throttle on down shifting so when coming to a juntion
down shifting from 3rd to 2nd i blip the throttle and it stalls, but it will not restart with clutch in , i have to put the bike in neutral to restart it..
took the bike to a dealer they did a upgrade on the ecu but the problem is still there. the bike is standard.
 
Those symptoms are just like mine when a coil was failing. Mine also has to be in neutral to start it but that's a clutch lever switch fault that I need to get sorted out.

In my case the problems seemed to settle down but came back with a vengeance. By then the coils smelled overheated. I replaced one and the other went down on the way home. I had swapped coils left - right but as both of mine were wonky it's little wonder that test had no useful effect.

The dealer told me the diagnostic computer will not register coil fault codes. A faulty coil(s) has to be diagnosed from symptoms.
 
Bendy toy said:
Those symptoms are just like mine when a coil was failing. Mine also has to be in neutral to start it but that's a clutch lever switch fault that I need to get sorted out.

In my case the problems seemed to settle down but came back with a vengeance. By then the coils smelled overheated. I replaced one and the other went down on the way home. I had swapped coils left - right but as both of mine were wonky it's little wonder that test had no useful effect.

The dealer told me the diagnostic computer will not register coil fault codes. A faulty coil(s) has to be diagnosed from symptoms.
Click to expand...

i will try the coils out on mine , would like to solve the problem other than that its a fantastic bike,,,
cheers karl
 
This sounds very like my Gs before it was fixed yesterday !
Open the Power Commander map editing tool and check the value of the first column in the table
(Throttle position 0%)
rpm1000 change 0 to 10
rpm2000 change 0 to 10
send the map to The PC let me know if this made any difference
 
Denz0 said:
This sounds very like my Gs before it was fixed yesterday !
Open the Power Commander map editing tool and check the value of the first column in the table
(Throttle position 0%)
rpm1000 change 0 to 10
rpm2000 change 0 to 10
send the map to The PC let me know if this made any difference
Click to expand...

Hello, I have no idea how to do that, never attempted reading from power commander before.

The latest for me is that I visited Blakemore Racing in Bristol who supplied and setup the power commander. Disappointingly he tested nothing accept to rev the bike hard which caused a backfire nearly every time on deaccelerate. He said this is not normal and did not believe it was the power commanders fault. He disconnected the power commander and it was still backfiring once one deaccelerate. I rode back to Plymouth. Going up the bike cut out only once in traffic. Coming back the bike cut out once slowing down to stop at a service station.

I haven't been out since. I need to ride and get the bike to fault before I move on further. BMW chap told me to remove a cap on left and right cylinder which is held by two screws, and see if there is any carbon build up as this has been known to cause a problem before. I haven't done that yet because I want to get the bike to fault at every stage.

Upon speaking with BMW further, its my suspicion that at least one coil is failing based on my symptons, what BMW have told me are the possibilities and what has been posted on my thread. But it's only a suspicion, nothing solid yet.

Either way, I don't really want to have to strip my bike back to stock for BMW to test cause I know its not the exhaust or the air filter causing that.
 
Mine (bog-standard 1200GS) was doing something very similar about a year ago - problem turned out to be the RHS throttle sticking ever so slightly open whilst the LHS one was closing normally. A nightmare to ride in London rush-hour traffic...

Bike was under warranty so BMW replaced the throttle body and problem solved.

Whilst it was idling like a pig it (and popping on deceleration) was sometimes possible to clear the problem as if resetting the TPS (i.e. slowly fully open and close the throttle 3 times with ignition on, engine NOT running) but in truth, this procedure was probably simply getting the RHS throttle to fully close.

Sorry if this gives you another variable to rule out.
 
Occasional stalling was the symptom I had when a lower coil failed, followed by poor running and heavy lambda probe fouling leading to failure of the lambda probe. The coil looked like it had exploded inside once the cover was removed.

I'd start by inspecting and testing your coils, especially the lowers which live in a fairly harsh environment.

To test coils, Steptoe recommends disconnecting secondary coils then riding the bike, then changing to secondary coils and repeating the ride test (you need to load the coils under cylinder pressure conditions to reveal problems).
 
Pukmeister said:
To test coils, Steptoe recommends disconnecting secondary coils then riding the bike, then changing to secondary coils and repeating the ride test (you need to load the coils under cylinder pressure conditions to reveal problems).
Click to expand...
I totally agree with Steptoe ! The only way to test the coil is to test it under the load (working pressure around 10-12 bar) easy way to simulate this is by increasing the gap between the electrodes X10 (0.8mm @ 10Bar = 8mm @ 1Bar ) I hope what I try to say here make sens to you
to see this in the practice watch this
good example :
Good coil should be able to create the strong spark over 12mm gap and voltage 15-20kV !
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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