OK, I haven't run across this before on a 4 speed, especially a new 4l80. What's going on is it shifts normally with light to even 70 or 80 percent throttle, but try to go WOT, it just bounces off of the rev limiter until you let off slightly then it'll upshift. Data in the log doesn't even show the upshift being commanded even though it's way past the speed and rev limit setting for the upshift.
Background on the truck - it's an 01 silverado 5.3 with a retro magnuson eaton blower setup like what you typically would find on an older ford. The original 4l60 burnt up and the truck sat for yrs. Was sold to the new owner, new owner had a 4l80 installed along with upgraded injectors and pump.
I've shifted everything around trying to get it to shift - it just won't at least with wot. I'm to the point of wondering if the turbine shaft speed sensor was wired correctly, but usually when that's not there, the 80's won't shift at all. It does act like it's not seeing the rpm input though. If the sensor wiring is backwards, will it cause this? In other words if it's pinned backwards?
I even tried doing the OS swap full write again just in case something didn't take the first time, but no go. The speedo is off, but if anything should make it shift sooner not later - it's reading 10 mph higher than actual. I know there's a few things wrong in the tune in general, but they just wanted me to rough in fueling then get the trans working. I've even tried lowering shift speeds for all to the point that it's screwed up all regular shifting.
The OS came from a 2500 4wd - never had one cause a problem like this before, but who knows. Just couldn't find one from a 2wd to try.