F800GS Don't want to start

Anyone run across this?

My 2010 F800GS with 4,000 miles doesn't want to start when cold or after sitting for a while.
When hot it starts instantly.

When cold it takes cranking with the throttle wide open for a while before it catches and starts. Several series of cranks so I don't overheat the starter or burn it up. But about 3-5 minutes before it goes.
Tried opening the fuel cap, etc.

Then, when it sits and although not cold, it does the same thing, but doesn't take as long to get going.

It's like it has lost fuel pressure or vapor locked (as cold - right...).

Any ideas??

Thanks!

Fuel pump?

That sounds like a fuel pump sticking or injectors sticking.

I can see a battery doing this, but usually if the battery has the capacity to support repeated cranking then it would have cranked fast enough the first few times to start it and wouldn't crank fast enough the last times to start the bike at all, at least with lead / acid chemistry.

With each attempt to start on a stuck fuel pump, the system will power the pump for only a few seconds, then shut it down and post a "fuse circuit 3" trouble code, on successive attempts it will try the pump again and often eventually break it free.


Even more likely is stuck injectors. These get pulsed repeatedly the whole time you try to start. Vibration and cranking will often un-stick them, and it takes a while for them to stick when you turn the bike off usually.

There are a whole bunch of other things that COULD cause this issue, but with modern BMW products the fuel pump and injectors are always the top suspicion because they fail so very often.

If you know what the injectors look like, you can remove the little black triangle cover thats held in by one screw on the right side and gently tap the injectors one at a time while cranking and they will usually un-stick immediately.

Thanks guys!

It's totally frustrating because yes, you would think if it has the power to repeatedly crank the engine it would start.

But, not true. The battery has to be completely charged for everything to function properly and start.

Plugged in the last two days on the BatteryTender and it starts right up. Didn't think I needed that since it would crank & crank.

The crazy part is I'd been riding all over the last week putting hundreds of miles on the bike. Apparently if the battery drops below a certain charge level simple riding is not enough to recharge it fully.

What I don't know for sure is if the battery is failing, but it's probably fine.

Now I'm certain, it's your injectors :)

Higher voltage from tender allowed enough voltage to unstick injectors.

Give it some time and you will become convinced. Keep your roadside card with you!

Too late for Techron???

Once they start sticking.... 50/50 techron will reverse it, but at the least it will prolong their life and make them easier to unstick road side.

Between the Boxers and 2 cyl rotax engined bikes, used to see 3 a day come in for the symptoms above or that just plain wouldn't start, as everyone started firing up their bikes after prolonged winter storage.

Used to make the no starts start by hooking them to a boost charger so we could see if anything beyond the injectors was also broken.

That little bit of extra voltage would almost always give the injector solenoids enough power to unstick, temporarily.

The fuel pumps would stick with about the same symptoms but it was less common and once the pump unstuck it would keep going.


The culprit is an aluminum bodied fuel pump that when exposed to fuel enriched with ethanol that was also contaminated with a little water, will oxidize. The aluminum oxide is just like rust and will make it through absolutely any fuel filter.

Once the aluminum oxide builds up on the injector valve, it sets up a galvanic reaction that pits it which in turn causes anything and everything to stick to the valve / seat and glue the two together.

Techron will do it's best to keep everything clean, but the valve is likely already badly pitted and will usually fail soon after either way, though not always.


BMW waffles on this from dealer to dealer and FSE to FSE and month to month. Sometimes they can it warranty, other times they refuse to cover it calling it incorrect storage or "bad fuel"


Our fuel does suck but the reason the injector failure rate is so high on these models is they share the same fuel pump body which is super sensitive to water contaminated ethanol enriched fuel.


The only sure fix is to replace the fuel pump, as it is what is poisoning the injectors, and as often as not, replace the injectors as well, after which, religiously use BMW or Chevron techron, especially before storage.

@Joel: what is Techron? Apologise if its a dumb question... I assume its something to add to the fuel... but never heard of it. And, its not available over here so maybe there are alternatives. I also assume that one should regularly add a little to the fuel to avoid that the injectors get stuck.

cya
Steve

It's a fuel treatment that virtually every automotive and motorcycle manufacture over hear rebrands and uses as their house fuel system treatment.

It's made by Chevron, AKA Standard fuel company, a very big oil company.

yes, you add it to every 10th tank or so though adding more often won't hurt anything.

Theres probably an equivalent over there, but to be honest, for both BMW, Volvo, and Ford, the USA is the country with by far the highest fuel system corrosion and varnish induced fuel pump and injectors failures.

Even third world countries have a lower failure rate then we do, as do first world countries that use greater percentages of ethanol.


The USA is special in regards to the combination of inadequate fuel additives, poor fuel station infrastructure, and mandated anti smog additives that are hard on fuel systems, but the K2X and K7X BMW platforms have well over industry standards of sensitivity to these same fuels.

Joel:

We'd have to replace the fuel pump with a non-OEM / non-aluminum-bodied pump yes?
Or has BMW "seen the light" and started making pumps that are not aluminum bodied?

You make me want to start figuring out which Denso pump would fit ... they are NOT aluminum bodied correct?

When I'm riding around town I usuall put an ounce or two of techron in every tank of gas...
Is that stupid?
AdvanceAuto does a two-for-one sale once in a while and I just stock up ... seems like cheap insurance.

Thanks,
Jim

I guess I am stupid too.

Thanks for the explanation. Most appreciated! We have something similar over here from Shell, BP etc. and its called either "Fuel Stabilizer" or "Fuel Conditioner". We also put it in the tank when winterizing the bikes.

Mh... as you say we do not have the problem over here very often. Coming from aircrafts I know that it would be possible to make the boost pumps housing corrosion resistant but would most probably cost more than a stainless steel housing. In DC-9 aircrafts the boost pumps are aluminum too and aircrafts have a lot more water in the fuel than cars. As far as I can remember during production the pumps aluminum is treated with Alodine which gives the housing a copper-brown color and after that they apply a green primer and that lasts for ever. Almost.

I have also seen racing fuel pumps where the housing is made of sinthetics so there would be many options to solve that problem. But, I also worked for Chrysler many years, changing a part is expensive and I can remember that replacing a plastic t-connector (about 2 cents worth) from the Voyager was denied as the new part (aluminum) would have cost 6 cent, plus 3 minutes for replacement. Not a huge difference but multiplied with xxxxx thousand cars world wide....

cya
Steve

It's not aluminum that is the specific culprit. It is aluminum that is not treated or protected in any way. Blame Bosch. BMW's custom fuel pump is just an off the shelf Bosch part in many other applications, all of which have this issue to a degree or other.

And it's not water that is the culprit, It is water combined with alcohol and the many other unbuffered acids the shit the USA calls motor fuels.

Aircraft would never have to deal with the shit that is in american automotive gas, and if they did, they would crash all the time lol.

As to the part number of a Denso pump, also aluminum bodied but treated, that will fit close enough. That and a zillion other treasures, figures, pictures, were all lost during my transition from employed to not. sorry.

Not your fault, thanks for hanging with us

Now that bikes are going out of warranty someone will have a dead one soon that we can use as the sample...

I am having the same problem on my f659GS but it is not starting after being on the tender any better, actually right now it is not starting at all. I hooked up my gs911 but get no fault codes. Guess it's time to haul it in. The frustrating part is that it was running so well even when it was starting hard. I'll post when I get a certain diagnosis.

Try and tap your injectors and get them to fire. That can un-stick them.
Then run a whole 16 oz can of Seafoam on a full tank once you get her running and blow her clean of the aluminum oxide particles. That could save you a trip to the dealer for non warranty service.

25 cents says it is the injectors or pump, but you aren't far from BMW of Denver, and they have an outstanding record on getting things covered under warranty that other dealers don't.

Tapping the injectors will un-stick them if it is the injectors. Pulling the pump controller and feeding it straight 12 volts or even jogging it both ways if its truly stuck.

But these are fixes if you are stuck in the bush. Warranty is better because even a whole truck load of sea foam or techron will usually only delay the eventual failure and that may happen somewhere more inconvenient.

Also if you unstick the injectors, it will make the job of the dealer diagnosis harder.

P.S. once done, use techron every 10th tank or so. Your dealer will stock it as it is a BMW rebranded product and their formulation is heavier on aluminum oxide inhibitors then the straight Chevron stuff at parts stores.

P.P.S. I like both sea foam and techron for prevention. I don't know which is best for prevention as it would take one hell of a large study to establish. But, for nursing sick injectors and pumps back to life, Techron concentrate works a lot better.

I established this at the dealer I worked by using sea foam on 10 bikes with stuck injectors / pumps, and using techron on about 100.

Thank you Joel and others for the input and I will follow your advice and haul it in, but probably to Northern Colorado BMW - they're a lot closer and I know them a bit. I have used Techron fairly regularly but will pay more attention in the future and make it become one of my first real religious rituals.

I don't know Northern CO BMW, they may be great, but wherever you take it, this is very likely warranty, so don't accept "improper storage" cause you were already using Techron. Dont accept "it's the altitude" cause thats BS and even the FSE that came up with that BS knows its BS. If they tell you "it's the alcohol in the fuel" Yes, this is true, but since they are selling a product in the USA, they still need to warranty it when fuel that meets our admittedly poor standards damages their product.

Good luck, let us know what it was.