I have a 1994 z28. The only prob I have is when I first start the car. I let it warm for about 10 or 15 min then drive it takes off slow and does not seem to shift gears (its an automatic) then if I turn it off ie. Get gas then start it back up and start driving its perfect! Any advise would be nice. Maybe a transmission flush????

 

With the cold weather right now, that might contribute.......... Mine shifts harsh until the tranny has warmed up when driving......

 

You might try scanning it for any transmission trouble codes. There could be an intermittent shift solenoid problem. Most trans codes don't make the check engine light come on. Any codes should be stored as long as you have not unpowered the computer or had too many drive cycles where the trouble no longer occured.