trans

1995 3100 lumina delay on start up drives in regular but won't drive in overdrive , do i need a new transmissin or would flushing it fix the problem

don't do a flush, just a filter and fluid that comes out when you drop the pan. While refilling, put a bottle of trans-x or Seafoam trans additive. It sounds like you have a TCC (torque converter control lock-up) solenoid sticking or going bad and the additive might unstick it. If the above doesn't help, you probably need a TCC solenoid replaced.