Separate names with a comma.
Discussion in 'Parallel Universe' started by chunter, Jan 3, 2009.
Here you go:
I would agree with the canister being filled with raw gas. I have seen intake manifolds blow up on cars that purged raw gas into the intake. DONT TOP OFF NEW VEHICLES!!!. Thats why cars have those warning stickers that say DONT TOP OFF TANK.
It is possible the stall is a purge of raw fuel flooding the engine, as soon as the engine dies the purge cycle is stopped by the ECU. Allowing the bike to restart right away because it just pushed all the raw fuel through the engine, any darker black smoke coming from the exhaust right upon restart could indicate this.
Since the charcoal canister is only fitted to bikes in the USA, it would stand to reason that if it's the cause of all this stalling the only complaints would be coming from USA riders. Does anyone know if this problem is being reported elsewhere?
I'm off to see what I find.
BTW; it's only happened to me once in the first 800 miles or so; I was downshifting entering a turn at a modest speed. I pulled in the clutch and restarted it with no drama, still rolling. I've never dropped the bike or done anything else that I would expect to lead to liquid fuel in the canister, but have regularly 'topped it of' when filling up. This thread is the first place I've ever heard a caution against that. There was no rain involved in any way.
I've seen users report the issue in the UK, New Zealand, Australia, Portugal, and Germany. The cannister may be part of the problem, or it may only be a red herring. Certainly reports of stalling in the rain would seem to have little to do with the cannister.
OK, it took about 60 seconds to discover that this problem certainly seems common in the UK as well, so I would say that makes the charcoal canister an unlikely culprit.
One interesting point gleaned from that reading is that when these bikes stall rolling, they can't be re-started by popping the clutch. They want to have their buttons pushed. That argues strongly for something in the ECU causing the bike to quit and then being 'erased' or 'overridden' by cycling it through the electric start procedure. I believe that the ECU is cutting the spark for some reason, because generally these events seem to be sudden, and not preceded by poor running (as though starving for fuel or flooded).
If I could ask a BMW programmer something, my question right now would be "What parameters cause the ECU to kill the engine?"
You will find a similar thread on UKGSER.com
I can confirm it is an ECU problem. . I've racked up 10,000 miles on my F800GS and it would always stall when I pulled in the clutch lever.
It had a recall and they did something to the ECU. Then they had me in again for an update on the previous recall. Apparently the first update created new issues to do with the fuel gauge display which was another issue of mine.
Anyway 4 months on and it hasn't stalled.
So Guys. In Summary. It is likely to be an ECU issue. The guy on the first post of this thread had only done 350 miles on the bike so that sounds suspicially like all the other guys on this side of the pond that had the issue in the early days of getting the bike
Maybe on the rolling observation. This bike is hard to push start. It was commonly believed that it was not possible to push start before several people (myself included) made it work just fine. Just dropping the clutch, even in 4th gear, usually produces a rear wheel skid without turning over the engine. So unless someone who knows how to properly weight the rear before dropping the clutch tries it, I would be skeptical on the need to power cycle. Might be so or might not be so.
Anything new on this issue, guys (and gals)?
I've been compiling some info from this thread and some others on other forums:
Charcoal canister (assuming BMW puts these on non-US bikes).
Fuel tank under- or negative pressure.
Fuel pump relay.
Service Bulletin # 0001307035 System update CD version 9.2 Section 1.2.
Fuel qualitytoo much moisture in the tank?
Fuel octanetry the next-lower octane rating?
It's happening to many people in many places (i.e. various elevations and climates) and during many types of actions (straight-ahead driving at high speed and low speed, during a turn, etc.). The cut-out is described as being as if the ignition is shut-off, i.e. the engine doesn't sputter and die, it just dies. Wonder if that implicates the engine computer or even just a faulty cable or switch design in the ignition switch or the kill-switch?
The first post had an interesting theory regarding an ECU malfunction. Later posts also discuss an issue with the TPS (Throttle Position Sensor).
Possible issue with fuel pressure sensor leading to erratic idle and engine cut-out.
Aalegado, I think we could safely eliminate several of these things. Please understand; I see where you are coming from, so don't take this in a negative way. You're compiling all the possibilities and keeping an open mind, that's useful. I'm just pretty sure there are a number of things we can rule out:
Low-fuel level: If the fuel level had anything to do with it, why would it not continue to cause the engine to die after the rider restarts it? I might expect the problem would continue to manifest until the tank was topped up, but I haven't encountered any accounts where the bike died repeatedly after being re-started. These engine-kill events seem to occur in an isolated, once-in-a-while way.
Charcoal canister (assuming BMW puts these on non-US bikes): You said it. As I understand, they don't.
Fuel tank under- or negative pressure: Again, why would the problem not continue to manifest? If tank venting were a problem, restarting the bike wouldn't help, it would only continue to get worse. Also, tank venting problems would logically be more pronounced under circumstances where fuel was being used rapidly. Many of these events seem to happen at the moment where the clutch is pulled in as the rider decellerates into a turn or down to a stop. At least on a less sophisticated bike, fuel tank venting problems will cause poor running at WFO, not a clean, momentary cut-out.
Fuel pump relay: Maybe?
Fuel pump: Maybe?
Service Bulletin # 0001307035 System update CD version 9.2 Section 1.2.: Where can I read more about this? Engine management systems or the sensors that feed them seem like the most likely culprits to me, so I'd like to know about this.
Side-stand switch: Maybe, although I'd expect that more in a rough riding situation and certainly we are seeing this on smooth pavement.
Fuel qualitytoo much moisture in the tank: Nah, I doubt it. That would cause continued poor running, not an abrupt, clean kill with an instant re-start.
Fuel octanetry the next-lower octane rating: Again, I find it hard to believe this posibillity for several reasons: Higher octane fuel isn't going to cause any running faults in an engine designed for lower octane. In our case, the engine is designed for higher octane fuels (by street standards), and running a lower octane fuel might possibly cause it some trouble, it certainly wouldn't seem likely to be helpful. The octane of the fuel isn't going to have any effect on momentary low or closed throttle operation. Generally, the running faults you will see with too low an octane will be detonation at high loads and/or high rpm. Also, pre-ignition or detonation will not stop an otherwise fine running engine instantly by it's self. It would take something like a faulty map doing something incorrect when the knock sensor (I assume there is one) detected the knock, and if this were the case, we'd expect to see the problem more in knock producing situations. Engine management programming usually responds to knocking (above a predetermined threshold) by altering the timing.
Ambient humidity: I live in the desert and have experienced the same symptoms reported by people riding in heavy rain.
In general, I don't think this is a fuel related problem, unless it's something that momentarily shuts off the pressure in the injectors. That would most likely be an electrical problem. Over all, I am much more inclined to believe it's the ignition that's being cut, or both fuel & ignition together, and this points to the ECU or the sensors that talk to it.
Two posibilities not on your lists:
From UKGSER: An experienced BMW tech said that it is essential on these bikes not to open the throttle when starting the engine as it resets the idle each time the engine is started. If you hold the throttle open that becomes the default tickover setting and then results in stalls when throttle is subsequently closed.
My post #55 on this list: Tight Engine - too much drag for the power being produced at low rpm/throttle closed.
Is anyone having the problem with >1000 miles on the bike? >2000 miles?
Now that is an interesting post. One thing that does not fit is the large number of reports of stalling in the rain.
How about the Fuel pressure sensor?? There was a recall in Mar 08 for them?
New fuel pump, after 50 days at the dealer. I went on a 200 mile ride, about 1/2 and 1/2. I'm off on a 10 day Baja/ Main land ride Thurs. That trip should confirm if it did the trick. I'm also VERY sure to not touch the throttle when starting the bike. What a sweet bike.
Yes, it is a sweet bike. BMW really got it right with this one. There is a lot to like. After too many bikes to count (and I still have a lot of them) this one sings to me.
I thought back recently to something I was told when I picked up my bike new from the dealer: I was told that when I started the bike, it was very important to tun the key and let the lights & gauges do their song & dance BEFORE pushing the starter. It was stated that pushing the starter button without waiting would "teach the ECU bad habits".
I am pretty good about remembering to wait, but I know once or twice I have just twisted the key and hit the starter. I am wondering if that happened the day my engine died?
Perhaps this has something to do with warnings other people have gotten regarding not twisting the throttle as you start the bike?
It still seems to me that something like the TPS being inaccurately calibrated at start-up would lead reliably to problems any time the throttle was closed after the botched start-up, where these engine kill events seem much more random.
It seems that the problem was actually the fuel pump (I'm pretty sure). They replaced the pump after a warning light came on, and I have not had any issues since (about 200 miles later now).
In your case that maybe so but BMW have acknowledged that the stalling issue is ECU related and cured by a software upgrade. I know 5 other 800 riders who had the same issue as me and it went away after the recall and software upgrade.
I would urge others to follow that tack with BMW USA before you start wondering if the alignment of the planets is making it stall.
Where could I read about this update? I'd like to be informed before I speak to my dealer. When I got my bike Nov. 1st, I asked if it had the latest software and the dealer said yes, but I don't know what version # it might be, or what date the upgrade you are talking about might have come out.
My issues were 3000 miles apart. At first.