A method for identifying a fuel injector characteristic may include generating a signal to supply electrical current to the fuel injector, and monitoring the electrical current supplied to the fuel injector. The method may also include identifying the characteristic of the fuel injector based on the electrical current, the characteristic including a type of fuel injector, and performing a corrective action based on the type of fuel injector which was identified based on the electrical current.

Electronic fuel injection control system for an internal combustion engine, the internal combustion engine being equipped with at least one fuel feeding line provided with a fuel tank, at least one throttle valve, at least one injector, at least one fuel pump, at least one fuel return line having at least one solenoid valve, at least one first fuel return duct that connects the injector to the solenoid valve, at least one overpressure valve, at least one second return conduit adapted to connect the overpressure valve and the solenoid valve with the tank, wherein the fuel return line is provided with at least one calibrator allowing at least the state of said fuel pump and relative performances thereof to be verified.

A fuel filter monitoring method includes receiving pressure signals that are indicative of a pressure drop across at least one fuel filter of a fuel supply system configured to supply fuel to at least one fuel injector of an internal combustion engine and receiving a condition signal indicative of a condition of a fuel supply system, the condition signal being generated by one or more of a geographic location sensor, an altitude sensor, and/or a fuel temperature sensor. The method includes estimating a remaining life of at least one fuel filter of the fuel supply system based on the pressure signal and the condition signal and outputting a notification indicative of the estimated remaining life.

Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes adjusting port-fuel injecting parameters in response to a learned direct injector fueling error.

An injector failure diagnostic device 1 diagnoses injector failures for a multi-cylinder internal combustion engine 2 having injectors 21 to 24, each injector injects fuel to the corresponding cylinder. The injector failure diagnostic device 1 includes: an operating sound obtainment unit 12 configured to obtain current operating sound that is operating sound when all of the injectors operate, and obtain pseudo-failure operating sound sequentially for each of the injectors, the pseudo-failure sound being operating sound generated by stopping the fuel injection from one injector while maintaining the operation of the remaining injectors; and a faulty injector identification unit 13 configured to determine whether or not the pseudo-failure operating sound of each injector obtained by the operating sound obtainment unit 12 is similar to the current operating sound to identify a faulty injector.

An injector diagnosis device 1 includes: an engine sound model generator 14 configured to generate a normal engine sound model and an abnormal engine sound model based on the number of cylinders of the engine and a combustion pattern of the engine; an operating sound obtainment unit 12 configured to obtain the operating sound of the engine operating with the combustion pattern; a frequency characteristics calculation unit 13 configured to calculate the frequency characteristics of the operating sound obtained by the operating sound obtainment unit 12; and an injector diagnosis unit 15 configured to diagnose whether or not the injectors have a failure based on the frequency characteristics of the operating sound which is calculated by the frequency characteristics calculation unit 13, and the normal engine sound model and the abnormal engine sound model which is generated by the engine sound model generator 14.

Appropriate detection of an abnormality of voltage information, which is a basis for correcting a fuel injection amount, becomes possible. For this reason, a fuel injection control device 127, which has a drive IC 208 controlling a fuel injection drive unit 207a to supply a high voltage to a solenoid 405 so as to open a fuel injection valve 105 and controlling the fuel injection drive unit 207a to supply a low voltage to the solenoid 405 so as to hold a valve-open state of the fuel injection valve 105, includes: a drive voltage input unit 211 that measures and outputs voltage information based on an upstream voltage of the solenoid 405 of the fuel injection valve 105 and a downstream voltage of the solenoid 405; a fuel injection amount correction unit 213 that corrects a fuel injection amount of the fuel injection valve 105 based on the voltage information output from the drive voltage input unit 211; and a voltage input function abnormality detection unit 212 that detects whether an output of the drive voltage input unit 211 is abnormal based on the voltage information output from the drive voltage input unit 211.

A method for monitoring a fuel supply system in an internal combustion engine includes the steps of: recording a first pressure value in the fuel supply system in a region of the fuel supply system associated with a pre-filter and upstream of a low pressure pump; recording a second pressure value in the fuel supply system downstream of the low pressure pump in a region of the fuel supply system associated with a primary filter; monitoring the first pressure value and the second pressure value for an error state of the fuel supply system; and recognizing the error state only if the error state is plausible on a basis of both the first pressure value and the second pressure value.

Methods and systems are provided for balancing fuel delivery amongst all engine fuel injectors. In one example, a method may include selectively adjusting an injection timing of one or more fuel injectors of a plurality of fuel injectors to increase an inter-injection period between two consecutive fuel injections in response to a request to balance amounts of fuel injected by the plurality of fuel injectors

A booster pump increases fuel pressure in a high-pressure system of a fuel supply system. A decompression mechanism reduces the fuel pressure. In case of a discharge abnormality of the booster pump which causes rise in the fuel pressure, the fuel pressure control system performs an abnormality handling to cause the decompression mechanism to stop the rise in the fuel pressure. In case of the discharge abnormality, and on determination of a warning-required state, in which the fuel pressure in the high-pressure system possibly exceeds a threshold pressure, a control device causes a warning state, in which the fuel pressure does not exceed the threshold pressure before the rise in the fuel pressure stops, even if the discharge abnormality occurs.