1994 Ford Tempo

Upon accelerating the transmission does not shift into the upper gears without letting off on the accelerator slightly. After it shifts up it wants to shift back and forth like it's bucking. Also while this is happening the speedometer is very irratic. I disconnected the EGR valve vacuum line and then the transmission would not shift at all, stayed in first gear. I disconnected the hose from the EGR valve temperature sensor results - no trans shift at all. I disconnected the electrical plug from the bottom of the EGR valve temperature sensor - no shifting and the speedometer would not work at all. Was shifting fine when I cut the car off then the shifting problem started when I started it back up and has continued since.