run away bike

[dwgreen]

I have a 2005 R3 with 67,000 mile. It has a KN with Tors exhaust. I was coming home last week, cruising with traffic and when I let off the gas low and behold I now had a cruise control I didn't know about. Still going 60mph coming off a corner into the I90-405 interchange. I managed that with Clutch , gears and about 3grand on the tach. When I was on the straight and narrow( car pool lane) I pulled the clutch and hit the kill switch. The bike restarted no racing engine but was running real rough. Any ideas what it could be?
I have had the bike since 2007. Usual issues with rattling, hard into neutral. I ride rain, shine but no snow or ice. It is my commuter transportation. I work in the medical field so I know bodies pretty well, but not so much bikes.

 

[evanr]

throttle position sensor could be on the way out. Has it ever been changed to the updated one ?

 

[TRath]

throttle position sensor could be on the way out. Has it ever been changed to the updated one ?

Mine was doing the same thing when my TPS started to go.

 

[tdragger]

No doubt it is the primary throttle position sensor. A lot of us have had the same problem. Easy to change out. Order one from your dealer and when it comes in, make sure that the insides are blue. The original on your bike will be black (you have to remove to make sure).

The tps is basically a rheostat. It develops a flat spot at cruise position and will hang up there.

Read the threads on changing out the tps.

 

[muleskinner]

Yea but would a TPS hold open the throttle? It's only a sensor for the computer to read throttle position. OP are you sure your throttle was not hanging up?

 

[tdragger]

Yea but would a TPS hold open the throttle? It's only a sensor for the computer to read throttle position. OP are you sure your throttle was not hanging up?

Yes, it would. This is a very well known problem with 2007 and earlier models. The sensor itself gets stuck in a certain position and sends that signal to the ECU which in turns holds the rpm up. The sensor is a mechanical rheostat.

 

[muleskinner]

Okay so explain this to me. If the TPS gets stuck and tells the computer the throttle is in a certain position, if you close the throttle plates how does the engine continue on at the same RPM? I could understand it if we had drive by wire systems, but we have cable operated throttle bodies on our bikes. Does the computer advance timing to make the engine run at the same RPM? With the throttle plates shut, it seems to me that would shut off the air supply to the engine. How can the engine stay at the same RPM with no air supply?

 

[Mittzy]

Okay so explain this to me. If the TPS gets stuck and tells the computer the throttle is in a certain position, if you close the throttle plates how does the engine continue on at the same RPM? I could understand it if we had drive by wire systems, but we have cable operated throttle bodies on our bikes. Does the computer advance timing to make the engine run at the same RPM? With the throttle plates shut, it seems to me that would shut off the air supply to the engine. How can the engine stay at the same RPM with no air supply?

Idle steeper motor? This is controlled by the ECU.
That would be my guess.

 

[Triple Trouble]

Muleskinner brings up a good point and maybe it is the stepper motor holding the throttle open but the bottom line is that this is what happens when the early bike's TPS starts to go and replacing it with one of the blue ones is the cure. My TPS (2005) is the original but I have started carrying a spare on longer trips.

 

[tdragger]

Yeah, we need Warp or one of the other wrenches on this board to chime in. All that I know is that when these symptoms are described regarding a 2007 or earlier bike, replacing the primary TPS has always been the solution.