Misfire under acceleration

[FredTheMan]

Hey all. Let me throw out the issues I have experienced on my 08 XB12STT, perhaps some of you can nudge me in the right direction.
1. Dead gauges happened a few times during a ride. Key off/on again and all good.
2. Fan coming on during a ride even when ambient is a cool 75F. RPM between 2500-3500 most of the ride.
3. Misfire under acceleration over 3500 RPM. Bike runs like a dog.
4. Changed spark plugs and spark leads, no difference.
5. Take to HD who says I need a new TPS. Fitted, TPS reset, and all perfect for 150 miles.
6. Misfire under acceleration back. Back to HD who now say it is leaking intake seals because AFV jumps between 80 and 140. Changed seals, no change. Idle rough between 500 and 1000 RPM with the occasional pop through intake.
Now I figure I must have a bum ECM but the guys from EBR and Tuniversity do not think so. They both say that poor idling or misfire is unlikely related to the mapping. Any ideas, please!

 

[kelly]

have the same problem now and then, always seems to be the other end of the ground cable was loose. well cant say i had the fan issue. there is a number of other things to check. just sit down with your bike and go over everything see what ya see ys know.

 

[thewanmanrules]

What mods have you done... Exhaust, K$N etc... or None... If none... Start with Grounds... Look Mainly at the Steering Head... Next is check the connectors on the ECM... Check the connectors for the VR and Stator for Corrosion... Also... Check your Voltage at the battery at Idle and 2500 rpms...

 

[newbueller91]

i had the same thing and those that went to the buell dragon 5 meet know how much time i spent trying to solve it.....when i put the engine back in the bike after getting it painted i put the fuel injector wires in backwards, so if you have dropped the motor or unplugged these wires for some reason just switch them, the front cylinder is getting more fuel do to the ecm automaticly give the back cylinder more to compisate for the heat due to the lack of air flow.

but that might not be it at all, if not go for the grounds.
hope this helps, good luck

 

[alan1018]

I'm still working on this same issue on my 07' STT, one thing I did myself was go into the ECM program with a spy cable and turned off the servo that controls the exhaust butterfly. I do have a modified exhaust and a K&N filter so I don't need the servo on anyway and after doing this it stopped the surging. The surging did however start up again because I blew the back off my exhaust and had to drive 100 miles with a gaping hole in it. Going to reinstall the fixed exhaust and reset the TPS and see how it goes. I'll follow up with you to let you know...

 

[alan1018]

I told you I'd follow up so just wanted to let you know I'm having the same issues even after I reset the tps, surging over 4k rpms and the check engine light coming on and off. I'm still doing some research to see what it is. Anything that you've heard keep me posted. Riding is not much fun since this issue has come up...

 

[spd579]

Cam position sensor

 

[spd579]

I mean crank*