Abstract: A method of diagnosing a fault in a common rail fuel system having a proportional-integral-derivative (PID) controller includes determining a first integral output corresponding to a first fuel flow condition and a first rail pressure setting. The method includes comparing the first integral output with a threshold integral output and determining a second integral output corresponding to a second fuel flow condition and the first rail pressure setting, when the first integral output is greater than the threshold integral output. The method includes determining a third integral output corresponding to the first fuel flow condition and a second rail pressure setting, when the first integral output is greater than the threshold integral output. The method includes identifying a failure in at least one of a flow control valve arrangement and a pressure relief valve of the common rail fuel system based on the first, second, and the third integral outputs.

Abstract: A machine includes a compression ignition engine fueled from common rail fuel injectors that predominately inject natural gas fuel that is compression ignited with a small pilot injection of liquid diesel fuel. When an engine shutdown command is communicated to an electronic controller, the supply of gaseous fuel to the gas rail is stopped and the gaseous fuel common rail is depressurized by continuing to run the engine and inject gaseous and liquid fuels while commanding a liquid pressure greater than the gas pressure. After the gas rail pressure has achieved an acceptable shutdown pressure, the engine is stopped. The gas rail pressure is then reduced to atmospheric pressure followed by the liquid fuel common rail being reduced to atmosphere pressure after stopping the engine.

Abstract: A common rail fuel system includes a common rail supplied by an inlet metered high pressure pump and fluidly connected to a plurality of zero-leak fuel injectors. An electronic controller controls pressure in the common rail predominantly responsive to a rail pressure error when outside of an overshoot avoidance condition corresponding to the error being less than a first threshold and a time rate of change of the error being greater than a second threshold. Pressure in the common rail is controlled predominantly responsive to the time rate of change of the error during the overshoot avoidance condition.

Abstract: A common rail fuel system diagnostic algorithm is executed by an engine control and real time to detect and identify a faulty fuel system component. Rail pressure data is processed through a digital resonating filter having a resonance frequency corresponding to a fault signature. A peak magnitude and phase of the output from the digital resonating filter reveals a degradation level of a fuel injector, and a phase of the output identifies which fuel injector is faulted.

Abstract: A method of diagnosing a fault in a common rail fuel system having a proportional-integral-derivative (PID) controller includes determining a first integral output corresponding to a first fuel flow condition and a first rail pressure setting. The method includes comparing the first integral output with a threshold integral output and determining a second integral output corresponding to a second fuel flow condition and the first rail pressure setting, when the first integral output is greater than the threshold integral output. The method includes determining a third integral output corresponding to the first fuel flow condition and a second rail pressure setting, when the first integral output is greater than the threshold integral output. The method includes identifying a failure in at least one of a flow control valve arrangement and a pressure relief valve of the common rail fuel system based on the first, second, and the third integral outputs.

Abstract: A machine includes a compression ignition engine fueled from common rail fuel injectors that predominately inject natural gas fuel that is compression ignited with a small pilot injection of liquid diesel fuel. When an engine shutdown command is communicated to an electronic controller, the supply of gaseous fuel to the gas rail is stopped and the gaseous fuel common rail is depressurized by continuing to run the engine and inject gaseous and liquid fuels while commanding a liquid pressure greater than the gas pressure. After the gas rail pressure has achieved an acceptable shutdown pressure, the engine is stopped. The gas rail pressure is then reduced to atmospheric pressure followed by the liquid fuel common rail being reduced to atmosphere pressure after stopping the engine.

Abstract: An electronic controller for a common rail fuel system detects a fault when a time sum accumulated error exceeds a threshold. The time sum accumulated error is left unchanged when the operating condition is transient, and either adds to or subtracts from the time sum accumulated error responsive to a rail pressure error and the operating condition being steady state.

Abstract: A common rail fuel system includes a common rail supplied by an inlet metered high pressure pump and fluidly connected to a plurality of zero-leak fuel injectors. An electronic controller controls pressure in the common rail predominantly responsive to a rail pressure error when outside of an overshoot avoidance condition corresponding to the error being less than a first threshold and a time rate of change of the error being greater than a second threshold. Pressure in the common rail is controlled predominantly responsive to the time rate of change of the error during the overshoot avoidance condition.

Abstract: A common rail fuel system diagnostic algorithm is executed by an engine control and real time to detect and identify a faulty fuel system component. Rail pressure data is processed through a digital resonating filter having a resonance frequency corresponding to a fault signature. A peak magnitude and phase of the output from the digital resonating filter reveals a degradation level of a fuel injector, and a phase of the output identifies which fuel injector is faulted.