Hi email me may be able to help just had same problems taken a while to sort but fixed it last week along with abs failure and pivot bevel box bearing bike keeps me on my toes. davidmarsden@gmail.com
Forgot to say snail, looking thru service record, my bike was ABS model, it was removed when bike was less than 3 years old, so it must have failed ! Seriously, we still rate the Behemoth Most Wonderful ?If it was a honda , it would be slated by press and public !
TPS reset doesn't fix a broken TPS .. In fact it's pretty pointless as the bike sets the TPS simply by you using it - the only way to reset the TPS on a 1200 us to reset all the parameters, which requires diagnostic equipment . Also remember that most of the advice you get on Internet forums is well intended but mostly guess work by people that haven't actually had your problem and are just repeating what they've read on other forums or from previous posts and passing it off as personal experience
Just as a quickie.
Re-check the seating of the thottle cable where it meets the injector on the right cylinder. Pull the outer up & down & check against the other side. It's common for them to snag.
As it's an old bike, when was the dreaded fuel pump controller last changed? Failure usually causes total failure, though.