My Throttle is Surging...

[Farzad the barber]

So I've had this problem emerge randomly with my 2004 R1200GS which has vexed me forever, and a dealer even said they have never seen this problem, and of course, it's impossible to reproduce due to the odd nature of its emergence.

The Problem: Again, this is very random and happens almost never (happily, although it did occur twice today, which is why I'm asking for help).
The engine will start to rev higher than idle, around 3500rpm, and it will hold there even though I'm not touching the throttle. I can use the clutch to bog the engine down and bring the idle lower, but when the clutch is fully pulled in the engine will spring back to 3500rpm. One time the idle started to, with the clutch pulled in of course (and while riding), to surge up and down around 2500rpm... really odd.

Does anyone have experience with this kind of problem? And if yes, can anyone give me pointers as to how I could go about fixing it? Is this the potentiometer? Someone has mentioned something like Idle Actuators... but I have no clue myself.

Thanks in advance and I really appreciate any information that anyone can provide.

 

[Bendy toy]

Mine started doing this after I removed the O2 sensors and fitted a Power Commander, but only in wet weather and then its not consistent. I believe its caused by weak mixture at tick-over.
My Power Commander connections are all good so the only thing I can think of is a water leak into the O2 sensor connectors. I sealed my open connectors by wrapping with self amalgamating tape. I need to re-do them to prove if this is the issue.

So check your O2 sensor connectors are clean and properly sealed. Also check the wires have not chafed somewhere. Failing that, maybe talk to Geoff at Hilltop about a proper diagnostic and remap.

 

[JerseyNeil]

I think he is in Canada Bendy. I would love to visit Geoff but even from Jersey it's an expensive option.

 

[Farzad the barber]

Thanks Bendy, Yes I am in Vancouver Canada!

 

[Pukmeister]

I would suspect it is a problem with your throttle position sensor.

It could also be a tight spot/fraying in your throttle cables, the throttle adjuster seatings or the cable splitter box beneath the tank (or something else mechanical holding your throttle butterflies open.)

Either of the above would result in your fuel injection rate being increased with a rise in revs.

 

[Bendy toy]

I think he is in Canada Bendy. I would love to visit Geoff but even from Jersey it's an expensive option.

It's hard to tell on CrappaTalk.
Hopefully BC has some engine tuning experts.

 

[haydw]

Exactly how my TPS issues started. High idle I couldn't fix, then ran like a complete pig and wouldn't idle at all. Would replace the TPS first or find another hexhead bike and borrow theirs to check. Its a 2 minute job to change.
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[Bendy toy]

I was stuck in London traffic yesterday with the engine getting ever hotter and the tickover began to hunt. It happened again on the way out with the engine not getting so hot. It wasn't dangerous but judging by the above comments, my TPS is probably on the way out.