I continue to have problems with my 06 Road King with 25degree inj,Kerker's,k/naf. and PCIII.When I first begin to ride the engine is fairly smooth. When the motor gets to normal temp it starts running rough. The exhaust seems to hit harder. It gets to be a pain in the back! I think its the ECM. With every thing I here about this Thundermax. Do you get rid of the ECM then add the Thundermax? Or is it the same principle as the PCIII? Note: the Bike did the same before the add on's. HD said nothing wrong. Every thing within specs. Any ideas would be great.

 

The ThunderMax replaces the ecm and if you use the auto tune it replaces the O2 sensors also. I don't know what you mean by, the exhaust seems to hit harder, but I would think you should be able to adjust some of the problemif not all of itout with the PC3.

 

Several possibilities, the way I see it.[*]Injector operative imbalance. While running in a closed-loop (O² feedback) the anomaly could conceivably be handled acceptably. The Delphi (stock) ECU runs that way at low/moderate throttle settings but goes open-loop (like the PC-III does everywhere) elsewhere. The problem would rear it head without changes to the fuel maps. And is this a transient state or maybe trending? The TMAX or DTT replacement ECUs could conceivably cover such a condition fairly well by running closed-loop all the time.[*]Too lean and the engine is overheating.[*]Stock ECU needs to be reflashed.[*]Got one or more "iffy" motor mounts.

 

glens,
can you explain more about your injector operative imbalance? Also what can be done to correct it.

Thanks,

 

Add some good injector cleaner to a tank of fresh fuel and suffer through it. Seemed to help my situation after a tank of particularly nasty gas recently. Apart from draining the junk out it can take a while. Like having an elective operation. During the recovery the discomfort is as bad or worse than the original symptoms but after a while you forget all about it and are glad you did it.

I mean one not flowing the same rate as the other, though it's expected they're identical. This could be caused by physical problems like maybe one is a little (more?) clogged. Maybe one's got a suboptimal connection somewhere in the wiring harness or the harness itself is damaged and not cleanly passing signal to it. Such problems could be largely masked by closed-loop mode since a lean condition would be indicated in the offending exhaust and so long as the difference from "normal" isn't too great (out of range) the ECU will just tell it to fire longer enough to get the job done. If the obstruction (assuming cause) clears then the report will become "too rich" and the ECU will accommodate that, too, whenever it can.

It would probably be a good idea to suffer through a tank of injector-cleaned gas before going to a dyno. It would be a shame to have a slightly-clogged injector be factored into the map and have the clog clear later. Then it would run rougher than expected (open-loop) and another appointment would be in order.

How to get **** about it? You could yank the intake assembly, pull one of the feed wires and crank the engine a certain number of revs, collecting the fuel for measurement. Then do the other [edit: using the same wire again]. Maybe yank one injector wire and run at idle in open-loop mode and sniff the exhaust. Then put the same wire on the other injector and do it again [edit: did I just say that? Silly me]. Probably several ways to accomplish this without dedicated bench-test gear. If you have several injectors to choose from you could find a matched pair.

This would be akin to target shooters indexing the brass so they load it into the chamber in the same orientation every time it's reloaded. Necessary on a day-to-day rider? Probably not. But it wouldn't surprise me if a lot of money were on the line for a race, stuff like this gets done in preparation. I know I'd do it.

Maybe I'll allocate some funds for a TMAX or DTT after some more research into which one I like better. So far it may be the DTT (it seems more like Unix to me and I'm a long-hair that way from way back). The PC-III does an admirable job but cannot cope with injector balance changes very well.

 

[*]
He's got an '06 RK which is open loop all the time. O2 sensor, closed loop touring models started in 2007

 

Didn't catch that, I guess. But it doesn't matter. If his injectors are imbalanced and not tuned-for as such the engine will run roughly. Just one of the possibilities. My mention of going closed-loop full-time only pertained to the TMAX or DTT anyway. Mention of the Delphi going closed-loop pertains to anybody with an '07 who finds this thread as a result of searching for similar problems to what they're having, if they do search successfully. The search feature here seems woefully inadequate in my experience; most times I cannot even find a post by me searching for exact words I know I'd used.