Marc ... Try this question on the Vintage board. I would try a bunch of things before I would play with the injection pump. Very little fuel goes to the injectors for each cycle so it maybe working but it may not be apparent. First, turn the engine without the plugs to insure oil pressure. Replace the plugs and fire the engine with primming gas or starting fluid. Only after it cranks and runs on starting fluid would I begin looking at the pump. First pump test would be to disconnect the pump linkage, hold the pump linkage in the full open position and fire the engine again with starting fluid. You should get something happen. If it still dead, begin with the injectors and work backwards.
Good luck and keep us posted.
190SL, 230SL 5-speed, 95 E320 Wagon, 01 E320 Wagon, MGB, Boxster 'S', 190SL "Barn Find"