I have a 94 Cav Z24 that had the same problem, u get about 50-55 mph that is when the Torque Converter would engange and then when u slow down to a stop the car would stall out.
Its easy to unplug the solenoid. Its a Blue Clip that has 3-4 wires coming out of it. I was able to reach from under my car with someone on topside to guide me and unplug it.
Since then the car has been doing fine.