Help if you can.

2007 Nightster.

Bike has been running like a champ all year. Today I left and it was acting really hesitant, like it was cold and carburated. The bike was actually warm because I had already ridden it from work to the chiropractor and that drive was fine. So...I decided to skip the rest of my stops and try to make it home. Then I noticed when I would pull the clutch in the RPMs didn't really drop. No matter what speed/gear I was in....if I pulled in the throttle I'd say it took over 5 seconds for the RPMs to drop back down to an idle. So....at the next stop light the RPMs finally dropped and it wanted to stall again. I take off....same thing...really rough. Next light was the opposite....the damn thing had to have been running over 2500rpm while the clutch was in....and they were 2500 of the roughest RPMs I've ever heard. I have a Thundermax with Auto-Tune so I've been going through their troubleshooting as well as all the basics like a leak in the exhaust or AC. Checked to see if my 02 sensors were tight, etc. TMax says to look at the IAC plunger which is located in the mouth of the throttle body on the top. I'm pretty sure I found what they mean...it looks like a silver missle. I flip my off/run switch and it moves up and down but its REALLY minimal. Anyone know how far they are actually supposed to move? Also if I do get it to run at all right now it immediately stalls and backfires out the throttle body.

Sorry for the long post. I'm leaving Thursday for a camping trip and this is the last thing I needed to have happen. Any suggestions/ideas are more than appreciated.

 

I do know what you mean, i've ahd it happen a couple of times on my 08.
It's got a SE a/c, SERT, thunder header and dyno.
with mine it does better if i let it idle for a bit before riding. The idle kinda steadys off a little.
It feels like some kind of ecm /sensor learning thing.
But it runs just ***** to the wall around town.
It's a fun bike. it definately goes now versus stock.

 

I don't know, have you changed anything since it last ran properly? could it be bad gas?...try emptying the tank and refilling with new gas and give it a run. could you disconnect the thundermax and try it back in stock configuration to see if it's the thundermax? can the thundermax be re-booted? try unplugging the ECM and replugging it? maybe remove the maxi fuse and reinstalling maybe something will reset? check electrical connections at battery and frame ground locations?