98 Mystique low transmission line pressure

CD4E transmission line pressure falls to 0 after going through the gears manually. I have a gauge hooked up to the line pressure tap. After stopping and restarting the engine, the pressure comes back for a short time again. I think it is electrically related to the EPC (Electronic Pressure Control) solenoid. It could also be the TPS (Throttle Position Sensor). Has anyone had this same issue and corrected it?

Replaced the solenoid pack and still have the same issue. That eliminated the EPC solenoid. WHAT ELSE WOULD CAUSE THIS?????