VARIABLE STROKE DIRECT INJECTION FUEL PUMP SYSTEM AND COMPUTER-IMPLEMENTED METHOD TO OPERATE THE SYSTEM
A variable stroke direct injection (DI) fuel pump system for an engine includes a DI fuel pump (136) having a stroke member (278) and configured to pump a quantity of fuel based on a stroke of the stroke member (278). The system includes a variable fuel pump actuator assembly (212) comprising an actuator member (270) configured to actuate the stroke member (278), a control valve (224) configured to control a flow of hydraulic fluid to the actuator member (270), and a hydraulic fluid pump (262) configured to pump the hydraulic fluid and be actuated by one or more lobes (216) of a camshaft (120). The system also includes an engine control unit (ECU) configured to control a variable stroke of the stroke member (278) by controlling the control valve (224) based on one or more operating parameters of the engine.