Abstract: This disclosure provides a fuel injector system and method in which the timing of events in during period of fuel injection of a piezoelectric-actuated fuel injector are estimated based on sensed forces within the injector. The force sensor is positioned between a piezoelectric actuator and a hydraulic link assembly mechanically coupled with the piezoelectric actuator, and the force sensor operable to output a signal corresponding to forces between the piezoelectric actuator and the hydraulic link assembly. From information contained in the sensor output signal, timing in the injection period of at least one fueling characteristic based can be estimated to allow for adjusting fuel injector characteristics to compensate for variations affecting fuel injection, such as manufacturing tolerances, environmental conditions, and deterioration/wear.

Abstract: This disclosure provides a fuel injector system and method in which the timing of events in during period of fuel injection of a piezoelectric-actuated fuel injector are estimated based on sensed forces within the injector. The force sensor is positioned between a piezoelectric actuator and a hydraulic link assembly mechanically coupled with the piezoelectric actuator, and the force sensor operable to output a signal corresponding to forces between the piezoelectric actuator and the hydraulic link assembly. From information contained in the sensor output signal, timing in the injection period of at least one fueling characteristic based can be estimated to allow for adjusting fuel injector characteristics to compensate for variations affecting fuel injection, such as manufacturing tolerances, environmental conditions, and deterioration/wear.

Abstract: A fuel measurement and control system for a gaseous fuel engine having a solenoid actuated fuel flow control valve which is electronically actuated to control a desired metering duration when the control system is operating in a fuel flow control mode. The fuel measurement and control system further includes mode control valve for switching the control system between a fuel flow control mode and a positive fuel shutoff mode, wherein the fuel flow control valve is prevented from opening when the control system is operating in a positive fuel shutoff mode. The fuel flow control valve includes a pressure balance chamber to balance the biasing forces acting on the valve from the gaseous fuel, wherein gaseous fuel is introduced into the pressure balancing chamber to provide the balancing forces.