a pressure relief valve normally blocking the auxiliary passageway can be opened to alleviate the pressure on the first valve application_number US 38089182 A description in order to facilitate understanding of the present invention first a brief description of a prior art distribution type fuel injection pump system will be given with reference to fig1 in fig1 fuel is conducted from an inlet 1 to a pump chamber 3 by the rotation of a vane pump 2 the cross sectional view of which is shown at 2a rotated through 90 u00b0 for clarity the fuel within the pump chamber 3 is drawn via an intake passageway 4 and a registering one of a plurality of grooves 6 to a high pressure pump chamber 7 by the rotational and reciprocal movement of a plunger 5 developed in response to rotation of the vane pump 2 fuel is forced out by the action of the plunger 5 through a plunger passageway 8 and a registering one of a plurality of distributing grooves 9 to the corresponding discharge port 10 and hence via the corresponding delivery valve 11 to the corresponding fuel injection nozzle not shown for injection into the corresponding engine cylinder also not shown the force of a main spring 13 determined by a control lever 12 which is connected to the accelerator pedal not shown and the force of a governor sleeve 15 of a governor 14 determined.