Pretty new to tuning here. I had an e-mail tune for my 2005 Tahoe. Truck runs good, has good power, but fighting an issue where with cruise on at 65mph, going down a grade, I can feel the TC locking and unlocking. I can see some misfires during coast, and I do have misfires when idling, but I have been told this is to be expected even with a baby cam. While driving I do not have any misfires.
I did already try making the MIN TCC PWM delay to 90. That did not change anything.
Truck is a 2005 Tahoe Z71 with an LQ4 swapped. LQ4 has a baby Summit 8718R1 cam, LS6 valve springs, Summit stock replacement pushrods, Melling trunnion upgraded stock style rocker arms. Have a low mileage set of OE LS2 injectors in it that were flow benched and all tested good. Running stock 5.3 manifolds, stock cats and Y-pipe to a 3" MBRP Cat-back. Running the stock LM7 intake manifold with OE airbox and intake tube. A lot of stock stuff. Only thing that I am unsure of, age wise, is the O2 sensors. Truck has 304k and these could be the original.
I have all new coils, NGK TR6 plugs gapped at .35 and new plug wires.
I have uploaded the tune and most recent datalog and the VCM scanner config. Around the 15 min 20 sec mark I begin a descent down a grade on the thruway maintaining 65mph with the cruise on. This is when I mostly will notice this lock unlock lock unlock situation.
Appreciate any thoughts or advice.