86 buick lesabre tranny problem

got a problem with this tranny, doesn't want to shift unless it gets up to 4,000 or 5,000 RPM's...checked vacuum lines, there ok, checked fluid, and its ok even changed it when i replaced filter in tranny...any help would be appreciated

There is a cable that goes from the throttle to the tranny that might need to be reset. The cable is mounted to the bracket using the adjuster assembly, and has a metal tab and a sliding peice on the end. The sliding piece is sqare (1/4 in thick), and connects to the cable right before the throttle. The other side of the slider is a fatter peice (1 in thick) that has a silver tab. Push the tab firmly in, and push black piece on the end of the adjuster all the way back into the adjuster unit. Then, go in the car and force the gas pedal all the way down to the floor (just slam your foot down. You might hear a popping noise, but that is the adjuster doing its thing). That should take care of the problem.