Fuel injector with independent control of check valve and fuel pressurization

This invention relates generally to fuel injectors having check valves, and more particularly to fuel injectors having a direct hydraulic control of check valves. A hydraulically actuated fuel injector has an electronically controlled actuator that moves an actuation valve member. The actuator can position the actuation valve member at one position to cause pressurization of fuel in a nozzle chamber for fuel injection, and at another position to hydraulically bias a check to halt fuel injection while maintaining full fuel pressure in the nozzle chamber indefinitely.