I have a 1994 Buick LeSabre that was running good until the end of December. I stopped driving it for a couple of months and started driving it last week after getting my transmission filter & fluid changed. Its not wanting to go into gear unless you put it in 1st then switch it up to overdrive. I have to do this at every stop light and stop sign. It also has a problem with starting to when you go faster then 45 or 50 mph.

Besides having hard time getting out of park after starting the car, it also run's on high idle for about 20 min's with out kicking down each time it's started even when warm.