A device is provided for pumping fuel through an internal combustion engine, comprising a pump cylinder and a piston reciprocable within the pump cylinder to define a pump chamber open at one end in which fuel is pressurized during a pump stroke of the piston. A fuel supply means is provided for supplying fuel to the pump chamber. The fuel supply means includes an electromagnetically actuated fuel control valve having an armature secured thereto, with the armature residing in a fuel-filled armature cavity. The armature electromagnetically cycled between a first position closing the fuel control valve and thereby closing the flow of fuel to the pumping chamber and a second position opening the control valve thereby allowing fuel to flow to the pumping chamber. The armature is a flat plate secured to the control valve and constructed with a series of flow through holes and/or slots of prescribed geometry to (i) assist in precluding cavitation errosion of the armature and/or fastener securing it to the control valve by the fuel within the armature cavity, and (ii) to enhance the hysteresis characteristics of the fuel control valve. Various embodiments are provided.