The car should do just fine without any OVP at all. There are two ways that the OVP affects the running. First is that the KE controller handles mixture correction. NOW this is IMPORTANT: a warm running, correctly adjusted system, will idle as good or better if the control unit is disconnected (same as no OVP).
Second the KE controller handles idle speed control. Again the designers of the system built it to do just fine, broken.
SO, if yours isn't playing this way it would be logical that it has something to do with one of those activities. I would try disconnecting them individually and see which acts the same as removing the OVP fuse. To do this disconnect the EHA for the mixture correction part and separately disconnect the idle valve. if pulling the fuse causes the car to die then disconnecting these actuators one at a time should give similar results.
My guess is on the EHA. Anyone one want to say why? What has to be happening for unplugging the EHA to cause the engine to die?
Bosch Master, ASE Master, L1
33 years MB technician