I am not expert, just going off of what I have read and seen, so keep that in mind!!! I have my 2-3 TCC lockup set way below the actual shift point... For example I am commanding locking up in 3rd at 68mph @ 93.8% and 100%, but I actually shift into 3rd at ~81mph.... IMO setting the last IMO as trannys wear they need more time to do things like shift, lockup, etc... Do you know what your tranny temps were when it did not lockup vs when it did?

yeah, the temps were ~145* in Phoenix but more like 115* on the highway. IAT's were thru the roof too, starting runs at 126* sucks!

When my tranny gets hot it acts kinda funny, also what does your tranny fluid look like? IMO you might just need to loosen up the tolerances on some of the tranny parameters, BTW how many miles do you have on your TC and Tranny, if you don't mind me asking... From so of your posts it sounds like you exercise your truck daily (which IMO, is a good thing)

Lol, excersize.....:eyes:
I drive it daily but only go WOT on 'occasion'. Fluid is level, very clean and smells good....actually it smells tastey :nod:
I have about 18K on the combo, most of which is 5 miles each way to work and back so their pretty hard miles.

Have you tried posting on HPTunner forum? On the EFI Live forum there is a member named Joecar that is really good at adjusting/tunning tranny parameters... You try PMing him or checking out some of his threads, you will have to do a little translating inbetween EFI Live terms and HP Tuners thou.... Even thou I have EFI Live I frequent the HP Tuners board when I have problems, since that board has a much larger user base...

IM SORRY BILL I WASNT SAYING YOUR VERTER WAS GOING OUT... HE WAS SAYING YOUR TCC SOLENOID COULD BE TO BLAME... SORRY ABOUT THAT