intermittent cylinder cutout

[Beemerman59]

Any ideas on this one would be welcome. Out of the last four times I have had the 1200 out, the bike has cutout out three times to run on one cylinder for several short periods of time say about ten seconds or so. First couple of times I had just washed the bike so put it down to possibly water in the electrics, but on todays ride I had the same thing but water can be ruled out. Today, about 20 miles into the ride the bike's been running as sweet as anything and then just suddenly cuts out to run on one pot. I keep the bike going until I can pull over safely. Kill the engine, leave a few seconds and restart - still running on one. Leave for about 10 minutes as I'm contacting my mates to say I won't make it, start the bike and its running as sweet as again. Spend the rest of the day dancing around the lanes down to Portland Bill and back with no further issues for a further 150 miles or so. Then, on the way home, the same thing - one cyclinder cuts out. This time I have to keep the engine running for a while to look for a safe place to pull over. Then the cylinder cuts in again and alls well for the next 20 miles till I get home.

I have just hooked up the GS911 and there's no error codes showing. I did have the tank off a few weeks ago and this all started after that so I'm inclined to think I have possibly knocked or pulled something slightly lose. I don't know which pot it was that stopped so the best thing I can think of is to take the tank off again and just check all the fuel and electrical connections. Weird, that it will do 150 miles just fine, cut out for 10 seconds and then be all right again. So, where to start?

 

[trainman]

Any ideas on this one would be welcome. Out of the last four times I have had the 1200 out, the bike has cutout out three times to run on one cylinder for several short periods of time say about ten seconds or so. First couple of times I had just washed the bike so put it down to possibly water in the electrics, but on todays ride I had the same thing but water can be ruled out. Today, about 20 miles into the ride the bike's been running as sweet as anything and then just suddenly cuts out to run on one pot. I keep the bike going until I can pull over safely. Kill the engine, leave a few seconds and restart - still running on one. Leave for about 10 minutes as I'm contacting my mates to say I won't make it, start the bike and its running as sweet as again. Spend the rest of the day dancing around the lanes down to Portland Bill and back with no further issues for a further 150 miles or so. Then, on the way home, the same thing - one cyclinder cuts out. This time I have to keep the engine running for a while to look for a safe place to pull over. Then the cylinder cuts in again and alls well for the next 20 miles till I get home.

I have just hooked up the GS911 and there's no error codes showing. I did have the tank off a few weeks ago and this all started after that so I'm inclined to think I have possibly knocked or pulled something slightly lose. I don't know which pot it was that stopped so the best thing I can think of is to take the tank off again and just check all the fuel and electrical connections. Weird, that it will do 150 miles just fine, cut out for 10 seconds and then be all right again. So, where to start?

have you had a look at the coils, maybe one has started to fall apart and the water has tipped it into failure, if the 911 is showing nothing it sounds like a fuel or spark issue close to the heads

 

[Smug]

Place the end of a screwdriver on the body of the injector when the bike is ticking over. Listen at the other end of the screwdriver and you will hear it taping. Try it and you will hear what I mean.

When the injector is operating you will hear a taping noise and when it is not operating there will be no taping noise. The next time it happens have the screwdriver handy and have a listen. If only one injector is taping you know that the problem is with an injector. If both injectors are taping you know that you have an ignition problem.

When it missfires the header pipe for the missfiring cylinder will not be so hot as the header pipe on the cylinder that is firing. This can be tested by squirting something like lube onto both header pipes. The lube will not burn off the missfiring header pipe so quickly. This will isolate which cylinder is not firing.

 

[EggChaser]

When mine did something like that it was the lamda sensor in the exhaust system malfunctioning, but not an outright failure, hence no codes reported back to the system.

 

[Fanum]

From the OP, it sound like it's not something which is load dependant, so perhaps that rules coilpacks out.....they tend to reveal themselves in certain rev/load ranges.

Fuel pump controller on the way out?


(Ignore me though, my recent history of fault diagnosis is somewhat tarnished )

 

[Beemerman59]

I'm not usually a believer in co-incidences so tend to think its something I have done with tank removal and replacement. I can do all the usual stuff on the GS911 - cycle the injectors, run the fuel pump etc. I'm not that well up on the workings of the fuel pump controller but would be inclined to think that would affect both cylinders. I thought about the coil pack as well as this could be the first indications of a failure but as said, I don't usually believe in co-incidences.

Both Lambda sensors give the usual widly varying voltage readings which mean little to me, but then I'm testing it with what seems like a well running engine when the GS911 is hooked up. Every time its occurred the engine has been hot and has restarted relatively quickly so I can't tell which header is hotter than the other.

Thanks for the feedback.

 

[Deleted account 190920001]

When it cut out and then came back to life while running did it do so with a bang? If it did then it's most likely spark related (unburnt fuel suddenly ignites) if it didn't and ran perfectly as soon as it fired again then I would say it's fuel. Most likely a dodgy connection but it could possibly be a bad injector. I think you probably need to get back under the tank and re-seat all the connectors, do the injector as well. My feelings is its fuel as sustained flooding of the plugs would kill them so it would fail to catch again.

 

[Beemerman59]

When it cut out and then came back to life while running did it do so with a bang? If it did then it's most likely spark related (unburnt fuel suddenly ignites) if it didn't and ran perfectly as soon as it fired again then I would say it's fuel. Most likely a dodgy connection but it could possibly be a bad injector. I think you probably need to get back under the tank and re-seat all the connectors, do the injector as well. My feelings is its fuel as sustained flooding of the plugs would kill them so it would fail to catch again.

Good point. When the engine came back to life it did so instantaneously and without any farts or bangs. Yes, I will reseat everything and this time I will make sure the tank is nearly empty as it was a bitch heaving it into position last time when it was virtually full. That's one reason I'm wondering if I have dislodged something in the process.

 

[Beemerman59]

Think I found the culprit

Having finally found some time it was tank off and have a hunt around time. Could'nt find anything obvious that I might have done previously taking the tank off and on so just took off the connectors on the throttle bodies one by one. Found the socket for the injection valve on the right hand pot a third full of water and that lovely turquoise coloured corrosion starting to form on the pins. So I think that must be it and I think would also explain why the problem exhibited itself under heavy braking or downhill sections. Must have been just enough to cause a bad contact. So, I have cleaned everything up and going to put it all back together and take it for a spin. Hopefully thats sorted.

 

[Pukmeister]

Hopefully thats sorted.

Not until you solve the cause of water ingress, and spray a corrosion preventative fluid to dispel water and keep free of further troubles. A bit of silicone grease around the connector will help.

 

[Beemerman59]

Not until you solve the cause of water ingress, and spray a corrosion preventative fluid to dispel water and keep free of further troubles. A bit of silicone grease around the connector will help.

Yep, already done

 

[Pukmeister]

Thanks for the heads up, gonna take a look at mine and practice what I preach, a blob of silicone grease on each connector should do the trick.