High Idle on 05 Classic

[KyMoonshine]

Hello all, the Rocket 3 has always been a bucket list bike for me and I was fortunate enough to get my hands on a very clean 05 with about 40k on the odometer. The guy I purchased it from said when he purchased it last summer it had a Check Engine light and it was for the Air Temperature Sensor which he replaced, he said he wasn't able to finish the job completely because he wasn't able to hook it up to something or other. It runs great but at random times it will idle up to 1500rpm or more when I stop at red light etc but will fall back down to nice low idle after some time, it will even be idled up while riding and makes my one mile gravel driveway very sketchy at times. I have looked around for a few hours online tonight and it seems this bike is more advanced than my Valkyries and Shovelhead the check engine light is not on but the idle issue makes it less fun than I know it can be when problem is corrected. Does it need some sort of tune? which is all new territory for me. Any info on where to start would be so appreciated. I already know this is probably going to be my favorite motorcycle. Thanks

 

[jake shaw]

Welcome to the forum. The primary TPS (throttle position sensor) may be causing your idle problem. also lube all the linkages in and around the throttle bodies. Good luck.

 

[atomsplitter]

Welcome from sunny North Texas. The TPS was prone to glitches on some of the earlier models. If the bike runs OK otherwise that's where I would start looking. If it was surging at low speed it is likely throttle body synchronization, but idle speeed up sounds like TPS.

 

[KyMoonshine]

Welcome to the forum. The primary TPS (throttle position sensor) may be causing your idle problem. also lube all the linkages in and around the throttle bodies. Good luck.

Thank you for your response, should I just replace the TPS and eliminate it as suspect?

 

[KyMoonshine]

Welcome from sunny North Texas. The TPS was prone to glitches on some of the earlier models. If the bike runs OK otherwise that's where I would start looking. If it was surging at low speed it is likely throttle body synchronization, but idle speeed up sounds like TPS.

Thank you, I was really hoping this community was as nice as the Valkyrie community is, it's nice to have a informative group that doesn't humiliate you for asking a question I'll look into the TPS as soon as my pinched nerve heals

 

[bikecrazy]

I had that problem with my '05, and replacing the TPSs (I replaced both) fixed it.

 

[Kevin frazier]

You really need tune ecu to set a tps, or balance throttle bodies or reset a code. Get tune ecu get it going. See sensor page, test and adjustments and you will have an idea of whats up. It is quite a bit to get going but tune ecu is a must to diagnose with an issue like this. You can atleast rule out many things. Could be fuel filter, fuel pump, what pressure are you getting, thats going deep to show tune ecu is 1st step in diagnosing. Im assuming youre not using tune ecu by your post. Lots of help here so you can get it going no problem, lonelec cable, tuneecu.fr, android device tablet, phone for some stuff, theres other ways but tuneecu i think is used by most.

 

[KyMoonshine]

Thank you, today on the ride to work it stayed at 2100rpm in traffic when riding and when at stop lights, it finally dropped down to normal as I rode into the parking lot, its about a ten min ride in heavy traffic, I really have to sort it out for it to be ridable

I use VAG-COM on all my old VW TDIs so I guess I'll buy Tune ECU and try to find to correct cable and do some learning lol

 

[KyMoonshine]

I had that problem with my '05, and replacing the TPSs (I replaced both) fixed it.

So there are two TPS sensors? or are you referring to the Air Temp sensor and TPS sensor?

 

[bikecrazy]

So there are two TPS sensors? or are you referring to the Air Temp sensor and TPS sensor?

I'm not a mechanic, but my understanding is there are two TP sensors, one towards the front of the bike, and one towards the back. I think I've read it's the front TPS that is usually the bad one, but it's an old bike so I replaced both.