W123/200, Auto

Recently the car stalled while driving, a sudden loss of power and dropped in rpm before engine stalled. When restarting, the engine have difficulties in ramming up the rpm to pass 3000rpm before stalling again. Only after a couple of restarts will the engine returns to normal idling and operating conditions. However, while driving there is always a loss of power/rpm intermitently in between the normal driving conditions.

Please advice, as I have renewed the AC pump, serviced the carb plus renewing the diaphragm.

What other areas to check...