A controller for determining an injection strategy for a fuel injector within a hydrogen fuel injection system within an engine, the controller comprising: an input arranged to receive an engine operating parameter and a pressure signal associated with the pressure of hydrogen fuel available for injection from the injector in the fuel injection system; a processor arranged to determine an injection strategy for the injector in dependence on the received pressure signal and engine control parameter, the determined injection strategy comprising one or more injector control signals to control operation of the fuel injector; an output arranged to output the one or more control signals to the fuel injector.

A fuel pump includes an electromagnetic intake valve including a coil winding portion formed by winding an electromagnetic coil around a bobbin and a magnetic circuit configuration portion constituting a magnetic circuit when a current flows through the electromagnetic coil. The magnetic circuit configuration portion includes a yoke disposed so as to surround the coil winding portion, and a predetermined part facing, across a gap, the coil winding portion in a radial direction of the electromagnetic intake valve. The dimension of the gap is set such that the coil winding portion and the predetermined part come into contact with each other first when an impact force directed from an outer side to an inner side in the radial direction of the electromagnetic intake valve is applied to the yoke or the coil winding portion.

In order to reduce the friction of a dry-running solenoid valve (1) with a valve housing (2), in which an electric coil (3) and a magnet armature (5) are arranged, and with a valve element (8) which can be actuated by the magnet armature (5) in an axial actuating direction for opening and closing the solenoid valve (1), in which the coil (3) generates a magnetic flux which, when the solenoid valve (1) is actuated, flows via a magnetically conductive valve housing outer wall (2c) of the valve housing (2) to the magnet armature (5), it is provided according to the invention that a magnetically conductive flux element (12) be provided in the valve housing (2) and introduce at least 80%, preferably at least 90%, and particularly preferably 100%, of the magnetic flux flowing over the valve housing outer wall (2c) into an armature end face (5B), facing the coil (3), of the magnet armature (5).