94 Lesabre Tranny problem

Okay I'll try to best describe this: First started in the winter, when I first try to put the car into drive in the morning, the car sometimes wouldnt go into D, if I passed the D position and went back it would go in. Also, now when I'm on the highway seems like it wont go into 4th(OD) position, rpms would stay at 3000 rather than shift down. If I let go of the pedal it drops right down, but if I press it again goes right back up to 3000. MInd you this doesnt happen all the time, could this have a solenoid that overheats. Any ideas on what this could be. Someone mentioned to me it might just need a shifter adjustment whatever that means.

Thanks.

can anyone help with this, because my mother is having the same problem????