Originally Posted by
village_idiot
The throttle closure is happening because you are hitting your rev limiter before completing the shift. The rev limit is 6500 and set to ETC. Your transmission is looking to see 38mph, and 6200rpm before commanding the 1-2 shift. Start by lowering your commanded rpm/mph on the WOT 1-2 to allow a little more buffer between commanded and rev limit.
Personally, I would start by lowering the commanded WOT shift RPM on the 1-2 to say 6000 and make a pass to get data without being on the rev limiter (hopefully). If it still hits the limiter, bring the MPH down from the 38 and make a pass