i have a 94 z28 and my trans is acting up in 1st gear...like taking off is fine part or 3/4 throttle and slips at wot or if going like 15-20 mph and hit wot rpms fly up and car dont accelerate....just puzzles me that its only full throttle when it acts up and only in 1st gear...any ideas? thanks

 

Could be an issue with either the forward clutch piston, forward accumulator piston accumulator or a 1-2 accumulator piston leaking and the higher pressure causes it to leak more than at lower pressures. It could also be the forward clutch not being able to hold with the additional load or even a pump. If this is really worn or warped the pump could allow oil pressure to get on the back side of the pump slide. This is causing pressure to go down under WOT and making the forward clutch slip do to lack of oil pressure with an increased load. Best of luck. Vince

 

here is an idea, your 1-2 is GONE!