Unbalanced rough idling and nearly stalling when starting from cold

[RSavage]

History:

Took the R1200GSA 2011 to Watlings on Friday for tyres and returned home without incident. After about an hour I started the bike to move it and it was running as if it had lost a cylinder - really rough, revs hunting and nearly stalling. Blipping the throttle makes it almost, or in one instance actually, stall.

One warm it's OK and I rode for ~ 50 miles with only one reoccurence early in the ride of the problem.

Starting it again today showed the same symptoms but not for as long.

So, what to check? I have no means of pulling the coils - which I understand requires a special tool to prevent damage.

One curious thing - which may be irrelevant or evidence of my failing memory - is that the rear TPS is displaying the tyre pressure from power on and I thought that front and rear display "- - - - -" until the bike has travelled a short distance. Front TPS is displaying " - - - - - "

Just to make my life even better I am (supposed to be) going to Spain on Saturday for a week.

Cheers

Richard

 

[Bendy toy]

The primary coils are easy to pull. You need a medium or wide blade screwdriver with a bend at about 30mm from the end. Use it like a little crow bar to lever the coil out.

The tyre pressure sensors probably need new batteries.

 

[RSavage]

The primary coils are easy to pull. You need a medium or wide blade screwdriver with a bend at about 30mm from the end. Use it like a little crow bar to lever the coil out.

The tyre pressure sensors probably need new batteries.

Thanks.

What does pulling the coils prove?

TPS readings are fine when the bike is moving.

 

[earthmover]

Mine did that a couple of weeks ago, and as I had just refilled the tank I thought it was shitty fuel. Next time out it was just the same, until I wrung its neck in second for a few seconds. Don't know what it was, but it runs just fine now.
Mark

 

[RSavage]

Mine did that a couple of weeks ago, and as I had just refilled the tank I thought it was shitty fuel. Next time out it was just the same, until I wrung its neck in second for a few seconds. Don't know what it was, but it runs just fine now.
Mark

I wondered about poor fuel and popped the cap in case the tank breather was clogged (made no difference). It's odd that it clears after a while.

 

[Steptoe]

I have no means of pulling the coils - which I understand requires a special tool to prevent damage.

There is no need to pull the coils. Leave them in place and just unplug the small electrical plug in the ends of the coil. .

Thanks.

What does pulling the coils prove?

To test if they're working correctly. Failed coil caps is a fairly common fault .

Disconnect both the lower plugs on each side from the coils. This means the bike will be running on just the main coils. If the engine only runs in one cylinder or not at all then one or both of the coil caps are fecked.
If it runs fine then reconnect the lower coils and disconnect the main coils and see if it runs on the just the lowers.

 

[Bendy toy]

Popping a coil out or unplugging the coil cable connector will tell you if the coil is causing the problem.

Engine stops its not the coil
Engine runs as before or only slightly more roughly its the coil. Or rather its an ignition issue - could be coil or spark plug.

Usually coils that are less than 100% will seem ok when cold but misfire when warm.

 

[RSavage]

Popping a coil out or unplugging the coil cable connector will tell you if the coil is causing the problem.

Engine stops its not the coil
Engine runs as before or only slightly more roughly its the coil. Or rather its an ignition issue - could be coil or spark plug.

Usually coils that are less than 100% will seem ok when cold but misfire when warm.

Thanks Both

It's been running fine today :-(

Yes, I would expect coil problems to manifest themselves as the coils become hot.

Brian (BGM at Pembury) has lent me a new TPS and checked fault codes - none found.

Might have a play with the coils connectors later.

Cheers

Richard

 

[RSavage]

There is no need to pull the coils. Leave them in place and just unplug the small electrical plug in the ends of the coil. .



To test if they're working correctly. Failed coil caps is a fairly common fault .

Disconnect both the lower plugs on each side from the coils. This means the bike will be running on just the main coils. If the engine only runs in one cylinder or not at all then one or both of the coil caps are fecked.
If it runs fine then reconnect the lower coils and disconnect the main coils and see if it runs on the just the lowers.

So I remove the rocker cover 'protectors', pop the rubber covers off the lower coils and then pull the leads off the coils and try to start it? Yes?

 

[Pukmeister]

The rough running symptoms you describe can be caused by the throttle position sensor (potentiometer) if they get wet or the internal carbon tracks or wiper arm contacts wear. Search the forum for TPS Reset and give it a try, it might resolve your rough running issues. I recently refitted my sensor and the bike wouldn't start, it took two attempts at TPS reset to get it to read 0-100% with my GS911 before the bike would start, idle and run correctly.

As for the RDC tyre pressure readout, sometimes the system continues to display the previous value or ---, I don't think you have much to worry about with it. Mr RDC sometimes stops reading altogether and throws up a yellow warning triangle, this has no effect on how the bike runs.

 

[Steptoe]

So I remove the rocker cover 'protectors', pop the rubber covers off the lower coils and then pull the leads off the coils and try to start it? Yes?

Put the tools down and step away from the bike.

 

[RSavage]

Put the tools down and step away from the bike.

Because? Ah, my enquiry suggests that I know nowt about bikes? Thanks Steptoe.

 

[RSavage]

The rough running symptoms you describe can be caused by the throttle position sensor (potentiometer) if they get wet or the internal carbon tracks or wiper arm contacts wear. Search the forum for TPS Reset and give it a try, it might resolve your rough running issues. I recently refitted my sensor and the bike wouldn't start, it took two attempts at TPS reset to get it to read 0-100% with my GS911 before the bike would start, idle and run correctly.

As for the RDC tyre pressure readout, sometimes the system continues to display the previous value or ---, I don't think you have much to worry about with it. Mr RDC sometimes stops reading altogether and throws up a yellow warning triangle, this has no effect on how the bike runs.

Thanks Adam,

As mentioned; Brian has fitted a new TPS and, so far, the symptoms have not re-occurred. Which isn't to say that it is fixed :-( The RDC question was only dropped in because I have never seen it display a reading at switch-on and mentioned it in case it was relevant.

Cheers

Richard