Valve timing detection in fuel system using off cycle sweep

A fuel system comprising:

• a fuel pump including a plunger movable between an advanced position and a retracted position in a plunger cavity formed in a housing;
• a spill valve movable between an open position and a closed position to open and close, respectively, fluid communication between the plunger cavity and a fuel port formed in the housing;
• a control valve assembly including a solenoid actuator, and a control valve movable in the housing in response to energizing the solenoid actuator;
• a control system having an electrical circuit including the solenoid actuator, and an electronic control unit, the electronic control unit being structured to:
• pulse the solenoid actuator with a plurality of current pulses of varied duration while the spill valve is at the open position;
• monitor an electrical property in the electrical circuit induced by moving the control valve between a first position and a second position in response to each respective one of the plurality of current pulses;
• and
• determine a valve timing of the control valve based on the monitored electrical property.

A fuel control system comprising:

• an electronic control unit structured to:
• pulse a solenoid actuator in a fuel system with a plurality of current pulses during at least one off cycle of a plunger in the fuel system;
• monitor an electrical property in an electrical circuit including the solenoid actuator induced by moving a valve in the fuel system in response to each respective one of the plurality of current pulses;
• determine a valve timing of the valve based on the monitored electrical property;
• and
• electronically trim the valve based on the determined valve timing.