Patent ID: 6845926

Claim:
A unit fuel injector, the injector internally preparing fuel during an injection event at a pressure sufficient for injection into an internal combustion engine by means of an intensifier piston, comprising: a single needle valve for injecting a single fuel into the internal combustion engine; and a selectively actuatable controller being in fluid communication with a source of pressurized actuating fluid and being in fluid communication with a substantially ambient actuating fluid reservoir, the controller having a first valve, responsive to a first electric actuator, for selectively independently porting actuating fluid to and venting actuating fluid from the intensifier piston and a second valve operably fluidly coupled to a needle valve first closing surface and responsive to a second electric actuator for selectively independently porting actuating fluid to and venting actuating fluid from the needle valve during the injection event for controlling opening and closing of the needle valve; wherein actuating fluid ported by the second valve to the needle valve first closing surface generates a force acting to close the needle valve.