The invention relates to a method for operating an internal combustion engine system (2), wherein the internal combustion engine system (2) is provided with an air intake duct (3), an exhaust gas duct (4) and an exhaust gas recirculation (EGR) system (5), wherein the EGR system (5) comprises an EGR conduit (6) that fluidly connects the exhaust duct (4) and the intake duct (3), and wherein a gas feeding device (7) configured to feed exhaust gas from the exhaust duct (4) to the intake duct (3) is arranged in the EGR conduit (6). The method is characterized in that it comprises the step of: providing a flushing liquid in the EGR conduit (6) upstream of the EGR gas feeding device (7) so as to flush and clean the EGR gas feeding device (7). The invention also relates to an internal combustion engine system (2) configured for being operated by such a method and to a vehicle (1) provided with such an engine system (2). The invention further relates to means for controlling the above method.

An engine including an exhaust bypass valve and an intake bypass valve. The exhaust bypass valve is disposed in an exhaust bypass channel connecting an outlet of an exhaust manifold and an exhaust outlet of a turbocharger to each other. The intake bypass valve is disposed in an intake bypass channel connecting an inlet of an intake manifold and an inlet of the turbocharger. An intake pressure sensor detects a pressure of the intake manifold. If an instruction value indicating an upper limit or a lower limit of the valve opening degree of the intake bypass valve is continuously output for a predetermined time or more, an engine control device determines that an abnormality occurs in at least one of the exhaust bypass valve and the intake bypass valve.

An EGR device is provided with: an EGR passage for allowing a portion of exhaust gas from an engine to flow to an intake passage; an EGR valve for adjusting an EGR flow rate through the EGR passage; a throttle valve provided in the intake passage; and an electronic control device which calculates a fully closed reference intake pressure based on an operating state of the engine during EGR valve fully-closing, and which diagnoses an abnormality due to valve-opening locking of the EGR valve based on the calculated fully closed reference intake pressure. The ECU determines a foreign matter biting abnormality of the EGR valve based on the intake pressure, and based on the result of adding the fully closed reference intake pressure, calculated according to the rotational speed and the load of the engine, to an intake-pressure increase allowance calculated according to the rotational speed.

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.

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.

Methods and systems for calculating a plurality of aging factors in a system operating an engine. The calculated aging factors may include one or more of fuel injector drift, exhaust gas recirculation valve obstruction, and mass air flow sensor bias. Mass flow throughout the system, and pressures and temperatures within the system, are observed in an approach that relies on mass preservation concepts to estimate drift, obstruction and bias estimates.

When it is determined that there is a likelihood of occurrence of an abnormality in a supercharger, a maximum engine rotation speed and a maximum MG2 rotation speed are changed to a low rotation speed side and operating points of an engine and a rotary machine are controlled such that an engine rotation speed and an MG2 rotation speed are respectively within ranges which do not exceed the changed maximum rotation speeds. Accordingly, even when the supercharger does not operate normally and an abnormal increase in a supercharging pressure occurs, it is possible to curb a high-rotation state of the engine rotation speed and the MG2 rotation speed. As a result, even when an abnormal increase in the supercharging pressure occurs, it is possible to curb a decrease in durability of components.

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.

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.