I know this is a real long-shot, but are you sure the throttle pulley on the side of the throttle body is not hanging up on something? This is almost starting to sound like something mechanical, rather than electrical......

Zach

 

12500 miles on mine and no issues! Love it!

 

From my research it's one of three things... TPS, IAC or my throttle body's butterfly is broken... This SUCKS! Time to start snoopin' and see what I can find.

Thanks for the suggestions so far, I will post my findings...

 

So it seems the problem was caused by the IAC screw on the throttle body. A strange coincidence that this problem occurred at the same time as my upgrade to the ThunderMax ECM's firmware. At any rate Zippers impressed me with their quick turnaround and Randy's support. I could live with this ECM on my bike for cross-country trips considering that with overnight shipping you can get it to Zippers and back in less than 48 hours...

 

A couple of things I've noticed watching these threads about "race tuners":

I think I will go with the T-Max again on my new bike for a couple of reasons. This problem, as well as a few others, turned out NOT to be the fault of the T-Max. However Zippers customer support was outstanding even though the problem wasn't caused by their ECM (they still overnighted an NEW module). We all know that customer support like that often does NOT come from Harley.

If the ECM ever does take a crap on us (which apparently is VERY rare), you still have the option of going back to the HD ECM if you happen to have it with you. You would probably need to install the factory air cleaner as well for any extended operation but could probably at least get yourself home without it as long as you take it easy...the bike will be running lean. I'm considering having my dealer install a slightly richer base map in my original ECM and not messing with all the dyno tuning. That way I could install the factory ECM as a spare. If I remember correctly, I think that Zippers told me that the factory ECM will work with the T-Max wide band O2 sensors.

There is a learning curve to this unit if you are going to tune it yourself. After all you're basically trying to become a race tuner overnight with all the adjustments that are available to you with the T-Max. Anyone who has ever raced and/or tuned race engines knows that the knowledge took some time to aquire...same thing with the wide range of possibilities available on the T-Max unit. But the people that seem to be having the best results are those who are installing the base map, letting Zippers make any adjustments that they want to their maps, and then just riding the darn thing and leaving it to learn.

Just my personal observations. Do you think I'm missing anything?