TunerPro helped me find what was goin' on with the tranny shifting issue on my red Z28. It tries to shift from 2nd to 4th gear under BIG POWER, whether @ WOT or not, when it drops to 2nd gear to pass a vehicle or just from a dead stop to get on the freeway...occasionally. Drivin' Miss Irene on Sundays the tranny shifts from 1-2 in .57 seconds & 2-3 in .68 seconds. Fluid level is constant...perfect (& clean)...under all conditions, and fluid temp. ranges from 157 to 194. Torque line pressure drops to zero when this occurs, stayin' there until re-engaging 2nd or 3rd gear when the RPMs fall to 2k - 2800 from red lining. "Tranny component slipping" bitmask shows OK, which leads me to believe it is a tuning issue. The previous owner had the PCM tuned for mpg over hp when he installed the cam, & that's the extent of my knowledge with that upgrade. So, Doctors, whaddaya think? Surgery to open the tranny cuz clutches are givin', or therapy on the PCM with tunin' tweaks?

 

There's a couple tranny builders that drop in to the "Drivetrain" forum once in a while. You might want to post this there.

 

I thought about that...would ya mind movin' it for me, please? I dunno how to do it without startin' over.