Abstract: An actuator and valve assembly for a hydraulically-actuated electronically-controlled unit injector is disclosed which comprises an electrically-energizable actuator including a movable member and a poppet valve connected to the movable member. The poppet valve has a first seat and a second seat and is movable along an axis between first, second and third positions. The assembly further comprises a device for biasing the poppet valve towards its first position and a device for accommodating misalignment of the first and second seats relative to the axis. The poppet valve is advantageous because it has high fluid flow control capability in a one-piece single-stage configuration.