An engine-knock controlling system for a carburetor-based engine includes one or more cylinders in which combustion occurs, wherein the system also includes a plurality of knock sensors coupled to an engine block, a first wiring harness, a first control unit, a second wiring harness, and a second control unit or an intermediate control unit, or a second control unit and intermediate control unit. The knock sensor(s) detects threatening engine-knock noise as an audible signal and transmits a signal through the wiring harnesses and control units to generate an ignition retarding action to correct the engine misfire and eliminate the knock/ping. Once the engine knock event is resolved, the processor of the first control unit transmits via the second wiring harness a signal to the second control unit or to the intermediate control unit, or to the second control unit and the intermediate control unit, to allow full-advance of ignition timing.

In a control device for an internal combustion engine in which internal EGR and external EGR are conducted, an ideal in-cylinder gas amount and an ideal in-cylinder gas temperature in an ideal state in which neither of EGR gas recirculates into a cylinder are calculated (steps 1 and 2). A mixed gas amount of intake air and the external EGR gas present on a downstream side of a throttle valve is calculated, based on a rotation speed of the internal combustion engine and intake air pressure (step 21) to detect a mixed gas temperature. An actual in-cylinder gas temperature and amount and an EGR ratio are calculated, based on the ideal in-cylinder gas amount, the ideal in-cylinder gas temperature, the mixed gas amount, and the mixed gas temperature (steps 24, 4, and 5), and an internal combustion engine is controlled based on the EGR ratio.

An engine-equipped vehicle capable of preventing gear noise and gear wear when the engine is started is provided. A multicylinder engine, a gear transmission that shifts power from the multicylinder engine by a shift operation, a centrifugal clutch arranged in a power transmission path from the multicylinder engine to the gear transmission, and an electronic control device that controls an operation of the multicylinder engine are included and the engine is configured to be started with a partial cylinder operation start where under control of the electronic control device, only some cylinders are operated and an operation of other cylinders is stopped.

A method for monitoring an engine cylinder in an internal combustion engine includes, for each engine cycle, detection of the ionisation current generated in the cylinder in a predetermined time interval of a combustion cycle, generation of a signal representing the ionisation current and comparing a maximum value of the signal with a threshold value. Successively, the value of one or more parameters associated with the signal can be changed with respect to an equal number of corresponding reference values when the maximum value of the signal exceeds the threshold value, to reduce the maximum value of the signal in the time interval of a successive combustion cycle. The presence of water in the cylinder can be determined when the maximum value of the signal exceeds the threshold value for a predetermined first number of combustion cycles occurring within a predetermined period of time.

The control device (50) operates to: calculate the ignition timing of each cylinder (101) of an engine (100) based on whether or not knocking is occurring; set, as a reference ignition timing, the ignition timing of any of the cylinders (101) for which the ignition timing is on the advanced angle side relative to the most retarded angle ignition timing on the most retarded angle side and on the retarded angle side relative to the most advanced angle ignition timing on the most advanced angle side; set an allowable timing difference range that is a range of an allowable timing difference with reference to the reference ignition timing; and when determining that the ignition timing of a cylinder (101) falls outside the allowable timing difference range, correct the ignition timing so that the timing difference with respect to the reference ignition timing falls within the allowable timing difference range.

An internal combustion engine of a vehicle is equipped with a plurality of cylinders, and ignition devices provided for the cylinders respectively. The vehicle is mounted with an ECU. The ECU performs an ignition timing decision process for deciding a basic ignition timing of the ignition devices in accordance with a load of the internal combustion engine. The ECU performs a misfire determination process for determining that a misfire has occurred on a condition that the torque has decreased below a threshold set in advance. The ECU performs a retardation process for controlling an ignition timing toward a retardation side from the basic ignition timing when a state of the vehicle satisfies a condition determined in advance. A determination on the occurrence of a misfire based on a relationship in magnitude between the torque and the threshold is not made during the retardation process, in the misfire determination process.

A fuel injection control apparatus including a microprocessor. The microprocessor is configured to perform calculating a target injection time, determining a first crank angle defining a start of fuel injection and a second crank angle defining an end of fuel injection, controlling a fuel injector in a first injection mode in which the fuel is injected for the first target injection time from a first time point corresponding to the first crank angle or a second injection mode in which the fuel is injected for the second target injection time from a second time point corresponding to a target crank angle, and the controlling including controlling the fuel injector so as to inject the fuel in an intake stroke in the first injection mode, while inject the fuel in a compression stroke in the second injection mode.

A reignition processing device for a gas engine for executing a reignition process of a cylinder during operation of a gas engine having multiple cylinders is provided with: an execution permission unit configured to, when at least one of the cylinders misfires, perform permission determination whether to execute the reignition process of the misfiring cylinder, on the basis of a damage diagnosis result based on an in-cylinder pressure of the misfiring cylinder, presence or absence of abnormality in a control device which performs combustion control and combustion diagnosis of the gas engine, an operational history related to the misfiring cylinder, and an operational state of the gas engine; and a reignition execution unit configured to execute the reignition process of the misfiring cylinder that is permitted by the permission determination to execute the reignition process.

In a control device for an internal combustion engine in which internal EGR and external EGR are conducted, an ideal in-cylinder gas amount and an ideal in-cylinder gas temperature in an ideal state in which neither of EGR gas recirculates into a cylinder are calculated (steps 1 and 2). A mixed gas amount of intake air and the external EGR gas present on a downstream side of a throttle valve is calculated, based on a rotation speed of the internal combustion engine and intake air pressure (step 21) to detect a mixed gas temperature. An actual in-cylinder gas temperature and amount and an EGR ratio are calculated, based on the ideal in-cylinder gas amount, the ideal in-cylinder gas temperature, the mixed gas amount, and the mixed gas temperature (steps 24, 4, and 5), and an internal combustion engine is controlled based on the EGR ratio.

An internal combustion engine of a vehicle is equipped with a plurality of cylinders, and ignition devices provided for the cylinders respectively. The vehicle is mounted with an ECU. The ECU performs an ignition timing decision process for deciding a basic ignition timing of the ignition devices in accordance with a load of the internal combustion engine. The ECU performs a misfire determination process for determining that a misfire has occurred on a condition that the torque has decreased below a threshold set in advance. The ECU performs a retardation process for controlling an ignition timing toward a retardation side from the basic ignition timing when a state of the vehicle satisfies a condition determined in advance. A determination on the occurrence of a misfire based on a relationship in magnitude between the torque and the threshold is not made during the retardation process, in the misfire determination process.