Misfireing at Idle

[JR]

After having the new up-date no idle fix I now have an intermittee misfire at idle. It worked perfert for approximately 75 miles and then started misfiring at idle. It sounds like it's trying to drop a cylinder. It also pops out of the exhaust on deceleration at times. Other than that the bike runs fine. It accelerates normally and cruises at highway speeds fine. I'm running a Power Commander and TORs with an open or empty cat box. Any ideas?

JR

 

[RiderRocketman]

Your PCIII tune probably got messed up after the idle fix, which could have loaded a tune too different from your last into the ECU thereby messing up your PCIII tune. You might have to go back to the tune that was in there before or re-dyno the bike.

Symptoms could also just be a loose plug wire. I'd check that they are all snug at the plugs and coils.

 

[JR]

Misfiring at idle

I checked out all the plug connections last night. The weird thing is that it worked or performed flawlessly just after the adjustment. It wasn't until I got back into my home town (approx. 75 miles) that it started acting up. I also disconnected the PC last night while checking the connections but, I couldn't tell that it changed the idle situation at all. Have you ever heard of anyones PC going bad?

JR

 

[RiderRocketman]

I have heard of PCIIIs going bad but the timing of your failure suggests something to do with the idle fix. Could be that during the trip home the ECU learnt some bad habits off the O2 sensor, but you PCIII guys are supposed to have an O2 sensor "delete' so that doesn't mess with your tunes.

Might just have worn out wiring and the fiddling during the dealer work might have made a wire snap. I replaced all my plug wires this year (3 years old) because one of them wasn't contacting the plug well. Got a more consistent idle. You might have a blown ignition coil too.

I'd try diagnosing that PCIII and see if it is working. Might just be time to upgrade to Tuneboy. Then you can do more diagnostics and reset your ECU tune and what not.

 

[JR]

Misfire at Ilde

Well, I took my bike back to the dealer and they found the problem. A vacuum cap had blown off one of the throttle bodies. So, of course with this missing the engine created a slight miss at idle. Everything is fine again. Also, it's been about 500 miles now with the new MAP without any problems.

JR

 

[dongee]

I also had idle problems; turned out to a vacuum leak. I have tors and cat delete, so I loaded dougl's 20050-2 tune with TB. I set the idle at 820, and now the she idles just fine, sounds great, and hauls ass!

dongee