Patent ID: 7255091

Claim:
A fuel injector for an internal combustion engine having a crankshaft, comprising: a cam-driven plunger reciprocatingly disposed within a bore to pressurize fuel within the bore; a nozzle member having a tip end with at least one orifice; a valve needle having a base end and tip end, being disposed within the nozzle member, and movable against a spring bias to allow a flow of pressurized fuel through the at least one orifice; an electronically controlled check valve in fluid communication with the bore and the base end of the valve needle, the electronically controlled check valve movable between a first position at which the bore is fluidly communicated with the base end of the valve needle, and a second position at which the base end of the valve needle is fluidly communicated with a drain; and a controller in communication with the electronically controlled check valve, the controller configured to: receive an indication of a desired start of injection timing relative to an angular position of the crankshaft, and a desired injection quantity; determine a displacement position of the plunger corresponding to the angular position of the crankshaft; determine a start of current for the electronically controlled check valve relative to plunger displacement within the bore that results in the desired start of injection timing; determine an end of current for the electronically controlled check valve relative to plunger displacement within the bore that results in the desired injection quantity; and affect the determined start and end of current for the electronically controlled check valve.