Once i put it into overdrive and try to accelerate it feels like its in neutral until it reaches a certain rpm then the car has a jolt. So i replaced the transmission fluid and fliter and both were dark but there was a burnt smell. But that didnt do anything. I dont know if it needs a new solenoid or if the tranny is completely shot. Any responses and advice would be appreciated.

Additional Info. 1995 Z, 63,000 miles.

 

Put the shifter into D1, D2 and D3 and tell us how it behaves.
If you can start in D1 or D2 and manually shift to D3 and then to OD for 4th gear, that indicates the forward sprag is shot. Unfortunately relatively common and requires complete trans rebuild and a converter cut/clean or replacement.

 

my trans had done something similar to me where it would not shift out of first until it hit about 5000 rpm, we tore apart the whole tranny and it was the 1st gear accumulator spring dont know if this helps but it might

 

My transmission was acting up the same way. I just pulled it out and now its time for a new FLT trans.