On a 93 the VSS is mounted on the rear axle next to the pumpkin that has to be working, pull it out and check for metal shavings. The tach sensor has to be working, mounted on the IP gear housing. The FLIP/TPS mounted on the drivers side of the IP has to be working. Check all of those. The connectors might be corroded. Check them.
Did you ever check the fuses?
Did you ever check the fuses?