Any 6l80 experts around?

[67Steven]

Thanks for the help.

I ran the truck up to Wong's Performance in Vancouver yesterday since he is a GM Corvette guru. The truck drove great 34 miles up there, not a hint of trouble.

He used a Tech2 and found 2 codes: Lost comms with CAN/BUS and ABS controller, nothing else. Apparently these were set up in my tune as 'throw a code, but not a CEL'. He removed them and updated my tune- then we ran it on the dyno. All the shift tables looked correct and it shifted where it was supposed to according to the scanner. No problems at all, ran up and down gears, the transmission was within 1 mph of the dyno and the Tech2. Got the engine temps up to 250 degrees and no problems, (other than a leaking radiator cap I discovered) We figured the codes might have been the culprit, so I drove home.

On the way , it occurred again. Engine really chugged to keep going until I could pull over. I am beginning to think it is occurring when the transmission has to shift up and down repeatedly- winding road the first few times, and stop and go traffic yesterday. I did notice that it held second gear instead of shifting to first at low speeds a couple of times. Since I had to get home, I reset the pigtail and drove the rest of the way home.

One additional item. When I pulled over, I was at a slight incline. I put it in park and hopped out to pull the plug. After a second or two, the truck rolled back to rest on the park pawl- almost like the transmission 'released' itself.

If it was the tune, why would it not act this way from the start? It drives awesome first thing in the morning- could heat be a cause of this? Should I run the trans through a dedicated remote cooler and not through the radiator?

Steven