I've got a 2007 FXDWG. Thunderheader, PowerCommander III, Feuling 525 cams, K&N air-cleaner, O2 sensor plugs. Just fyi, this is EFI.

This setup had been running fine for couple of years. Last week, this happened:
- After I've ridden 5 minutes or so, rpm's will stay up around 3000. This is in gear or out.
- Sometimes when I pull in the clutch, after 5-8 seconds, the idle will slowly come down.
- Often, I have to pull over, turn the bike off, then restart. Idle is normal until I've started riding again.
- When giving it gas, it will cut-out and pop, then accelerate.

The only change to my setup is the installation of a Jagg oil cooler, since the basic setup I mentioned above.

Plugs look okay, butterfly in TB is opening/closing okay.

I'm stumped.

 

Can you pull up a monitor of what your motor is doing using the PCIII? Symptoms sound like a possible engine temp sensor problem, just my best guess. Had mine go out recently, bought one for $35 and replaced myself, and I get solid engine temp readings now. Idle was all over the place and now steady.

 

Unplug the PC3 and see if the issues persist. PC3s go bad. Plug the bike directly into the ECU and leave the PC3 out of the circuit completely. It might not run the best (no tune), but I would bet the RPM thing will disappear. If this ends up being the case, buy a used PC3, transfer the settings and you would be back in business.

Most folks simply do NOT protect the PC3 correctly from water and rain, the PC is NOT waterproof itself. Also, look at all the pins where the PC plugs into the bike. Clean those with toilet bowl cleaner and a q tip. Lime-away works well for this purpose, too.

PCs are bad MOJO in general for a bike, due to DJ using square pins and our bike come with round pins.

 

I always say if it's an idle problem check the IAC (idle air control) first. If that is the problem its a cheap easy fix.

 

Thanks. I considered that the pcIII might have gone bad. I checked the diag codes, found P0134 Front Oxygen Sensor Inactive, P0374 CKP Sensor Synch Error. I cleared those and rode it again and those aren't reappearing. I'm also wondering about fuel pump and/or filter. But definitely will disconnect the PC and see what happens.

 

That would be first in my process of elimination too.

Yet another reason NOT to use EPA compliant "air cleaners" that put oily air into the throttle body.

 

I dropped the ball. I think of DBW bikes all the time... Yes, first order of business would be to spray some carb cleaner at the IAC and try to get the goop out.

 

Was definitely worth the $6 for me!!

 

This issue still occurring.
* I took the PCIII out of the equation and problem still happened.
* I carb-cleaned the IAC, wasn't too bad, a little black came out while cycling the fuel system.
* I replaced the ETS.
* I replaced plugs and wires and put in a new battery. They were due anyway.

A refinement of when this happens; engine is a full operating temperature. I've been riding freeway @ > 65mph. If I pull over, turn off the ignition, then restart, the idle is normal until I start riding again. Once symptoms start, bike hesitates/sputters off the line, misfires.

If I pull into the garage when the bike is hot, shut it off, restart, idle seems normal. I then whacked the throttle open all the way, quickly. The RPMS stayed @ 3k or greater. So now I'm wondering about the throttle position sensor.

 

If this were an automobile I would also look for vacuum leaks.