Your car has both items. The charge overpressure switch shuts off the fuel pump if boost pressure gets too high. The EZK unit determines the spark advance and controls the Power Stage. The Power Stage is the ignition amplifier and controls coil current. It is located above the battery on the inside of the left fender well in your turbo car. The Power Stage could be your problem.

I would suspect the Hall effect sensor, or the wires to it. Does the tach drop to zero when the engine stalls? If so, you have a problem with the low voltage side of the ignition system. Sometimes the Hall effect connector breaks out of the distributor and hangs by it's wires. That is great for an intermittent stop. Ask me how I know!