Patent attributes
A fuel injector for an engine is disclosed. The fuel injector has a plunger disposed within a bore, a nozzle member, a valve needle, a check valve, a spill valve, and a controller. The check valve is movable between a first position at which the valve needle is communicated with the bore, and a second position at which the valve needle is fluidly communicated with a drain. The spill valve is movable between a first position at which fuel flows from the bore to the drain, and a second position at which the fuel from the bore is blocked. The controller moves the spill valve toward its second position and the check valve toward its second position during a downward displacing movement of the plunger. The controller detects an unsuccessful movement of the check valve to the second position, and prematurely halts the current injection event in response to the detection.