You need to have fuel pressure for the system to work. You can't condemn the distributor till you have checked fuel pressure.
Does the airflow meter flap offer resistance when the pump runs compared to when its not running. The pressure drops in half instantly on fuel pump shut-off this is a distinct difference in the feel of the flow plate. Jump the fuel pump to test the feel with pressure (?). Also while cranking try pushing down on the plate massive misaddjustment can keep fuel from flowing till large plate movements.
Bosch Master, ASE Master, L1
33 years MB technician