We are having a G8 being a pain the neck.
Back story G8 came in with a smoked 6l80. Metal everywhere. Customer didn't like the price of new pump, stator, and TEHCM so we told him to bring us a core. We rebuilt the core he brought us. Reybestos reds, Koleene steels, zip kit, plus the normal seals and such. We installed a Circle D 265mm 3600 single disc stall as this car has some unknown spec pretty big cam. Car had a 9.5" PTAC 3600 triple disc when we first recieved it.
We tuned the car after the rebuild with no major issues. Customer takes car home for a week and then calls to report a P0796 and limp mode condition. This is also the same situation that caused the customer to first reach out to us. Said he had to drive it 20 miles home and then parked it. We go pick it up and trailer it back to the shop. We start bouncing this situation off one of our mentors in building these. He said put a new TEHCM in, his shop quit reusing them a few years back due to issues like this. We noticed a pin pushed almost all the way out on the connector so we also installed a new pigtail at this time. We pull trans pan and have red fluid. Install our new TEHCM and have it programmed. Upload our tune and this is what we get now ( log Converter_Normal 1:58 time stamp) When the conveter it locked with TCC pressure and you go to give throttle input, it unlocks and starts this harsh bucking/slipping. We showed this log to our mentor and he thinks the converter is done but did say reach out on the tuning side before we pull this thing again. We did pull the trans when this issue came up. Everything air checked before pulling. Disassembled every clutch pack, they were perfect, rechecked clearences, reassembled and air checked again.
So we are asking for some guidence on the tune side here. Is there anything we can try at this point? If the converter is bad what toasted it? That way we can get in front of it once getting this converter rebuilt.
And just brainstorming here, would the G8s 2.92 rear gears make something like this happen? or a pain to get this stall dialed in?
I also attatched a log of the car with the conveter commanded unlocked. Thing drove fine.
Thanks in advance