1989 Other Oldsmobile Models Oldsmobile Cutlass Ciera not sh

There's something unusual going on with my 1989 olds cutlass ciera. It only shifts at the redline. The transmission acts as if the pedal is constantly at full throttle, even though it's not. If I floor it when the car is in 2nd gear at low speed, the tranny does not go back down to first. It just stays in second. Once I slow down enough, it goes back to first gear.

so heres the summary: the tranny only shifts at the redline. It goes to 2nd at 45 mph, and 3rd at 85 mph, and it doesn't go fast enough to even get near the redline in 3rd gear, so it won't go into 4th. When I do a kickdown to attemtp to get it to shift into a lower gear, it doesnt do it.

My theory: Either a throttle position sensor or a engine vacuum sensor has gone awry, because i've heard that the ECU uses one or the other to determine when to make the tranny shift.