Re: 93 Tempo trans question
Could be the speed sensor, but the tempo speedometer is a cable driven unit.
The first thing I would check is the throttle pressure rod that goes from your transmission to your carburetor or throttle body linkage. This controls the shift points. Often the little plastic bushings that hold it on, get brittle from the heat, breaks into pieces and falls off causing the symptoms of over revving and hard shifting or slow shifting.
If that is not the problem then it could be a piece inside the trans. There is a plastic gear inside your transmission -- yes, plastic how genius is that!. That gear can warp and become perfectly rounded off. Replacing this is a pain in the butt. Almost the entire transmission has to be removed and reassembled.
A tranny shop can do it for you for around 150 - 200 in laboor, depending on your location it may be higher. If you do it yourself you can get the part for around 50USD. You will need to removed both axles, remove the tranny oil pan, remove the 6 bolts around the axle seal on the drivers side (these bolts are for the diff bearing retainer and one of them should be a Torx drive). You can then pull the retainer out while supporting the differential to prevent it from falling on the ground. Lower the diff assy. out (which includes the plastic gear) and replaced it. Reversing the steps for reassembly. BUT I WOULD LOOK AT THE FIRST SOLUTION PRIOR TO DOING THE TRANS WORK.