An energization control unit is configured to perform a constant current control by repeatedly switching between an on-state and an off-state of at least one upstream switch provided in an energization path of a coil of a fuel injection valve to control opening of the fuel injection valve in a drive period in which the coil is energized to drive the fuel injection valve. A current detection unit is configured to detect a coil current flowing through the coil. A valve-opening detection unit is configured to detect valve-opening timing of the fuel injection valve based on a change in at least one frequency spectrum of the coil current in a constant current control period in which the constant current control is performed. A valve-opening correction unit is configured to correct valve opening of the fuel injection valve based on a detection result of the valve-opening detection unit.

A method for identifying a type of a fuel injector installed in an internal combustion engine includes generating a control signal to supply electrical energy from a power source for actuating the fuel injector, monitoring the electrical energy, identifying a pattern in the electrical energy, the pattern being indicative of the type of the fuel injector, and outputting a notification indicative of an incorrect injector type based on the pattern.

A system includes one or more processors that are configured to obtain a measured fuel consumption rate for an internal combustion engine while the engine is operating at a predetermined operating condition to perform a mission. The one or more processors are also configured to compare the measured fuel consumption rate with an expected fuel consumption rate for the predetermined operating condition. Further, the one or more processors are configured to determine whether an injector flow limiter is in a latched condition based on the measured fuel consumption rate compared with the expected fuel consumption rate. Also, the one or more processors are configured to perform a responsive action responsive to determining that the injector flow limiter is in the latched condition.

The present invention provides a high-efficiency and highly-reliable fuel injection control device that controls a fuel injection valve of an internal combustion engine and can perform injection amount control in accordance with a deterioration degree of the fuel injection valve. A fuel injection control device controlling a fuel injection valve of an internal combustion engine includes a deterioration determination unit that determines a deterioration state of the fuel injection valve, an injection amount learning unit that learns the injection amount of the fuel injection valve, and a learning frequency change unit that changes the learning frequency of the injection amount learning unit in accordance with the deterioration state of the fuel injection valve.

Methods and systems are provided for monitoring a fuel injector of an internal combustion engine. In one embodiment, a method includes: receiving a set of feature data, the feature data sensed from a fuel injector during a fuel injection event; processing, by a processor, the set of feature data with a decision tree model to generate a prediction of a fault status; and selectively generating, by the processor, a notification signal based on the prediction.

An injector failure cylinder diagnosis method based on signal deviation of an injector failure diagnosis system measures, by a controller, noise/vibration signals due to the combustion of an engine, separates an injector abnormal frequency band signal as an injector signal from the noise/vibration signals, divides cylinder number time series data, which use a signal maximum value of the noise/vibration signals as a cylinder #1, into segments, extracts a feature vector after confirming a segment number of the cylinder #1 with a vibration reduction signal of the noise/vibration signals re-measured using one of the cylinders as an idle cylinder and sorting it by injector causing vibration time series data, and confirms a failure injector with the feature vector, thereby independently diagnosing whether the injector for each cylinder is normal or abnormal considering the deviation of the noise/vibration signals between the injectors for each cylinder from the measured noise and vibration signals.

A control device and a diagnostic method according to the present invention is applicable to an internal combustion engine provided with a first fuel injection valve and a second fuel injection valve for a cylinder. When there is an abnormality that makes an air-fuel ratio of the internal combustion engine richer than a specified value, it is determined whether the first fuel injection valve or the second fuel injection valve has the abnormality, based on change of the air-fuel ratio occurring as a result of first injection control for performing fuel injection while changing a distribution ratio of a fuel injection amount distributed to the first fuel injection valve to a fuel injection amount distributed to the second fuel injection valve, and a value of the air-fuel ratio obtained as a result of second injection control for performing fuel injection while maintaining the distribution ratio at a predetermined ratio.

A method of testing a fuel injection system or components thereof includes running a high pressure fuel pump to provide fluid under pressure to the fuel injection system or components. The pump flow is controlled via an inlet metering valve by controlling current or voltage supplied to the inlet metering valve dependent on the power to the fuel pump.

Disclosed is a method of alerting to the state of a high-pressure pump of an engine including a relief valve, a threshold pressure defining the opening pressure of the relief valve, the pump supplying fuel under pressure to a chamber equipped with a pressure sensor, including the following steps: initializing a computer when the engine is cut off during which cut-off a threshold pressure and a value of a first counter are collected in a memory associated with the computer; measuring the pressure of the fuel in the chamber; incrementing the first counter if the pressure of the fuel in the chamber is above or equal to the threshold pressure; and triggering an alert when the value of the first counter crosses a predetermined threshold.

Provided is an injector control unit capable of preventing unintended fuel injection other than an engine drive period. The injector control unit includes a cutoff mechanism for cutting off current supply to the injector from at least the ignition OFF to the next ignition ON.