An engine controller includes an ignition timing control unit and a rich imbalance determining unit. The rich imbalance determining unit designates one of multiple cylinders as a subject cylinder for determination and executes lean active control that commands a smaller amount of fuel injection for the subject cylinder than for the other cylinders. The rich imbalance determining unit determines whether an air-fuel ratio of the subject cylinder deviates to be richer based on a rotational fluctuation amount of a crankshaft during the execution of the lean active control. The ignition timing control unit executes an advancement limiting process that limits advancement of the ignition timing by the knock control during the execution of the lean active control.

A control device for an engine is provided, which includes a knock intensity sensor configured to detect a knock intensity, an output adjustment mechanism configured to adjust an engine output torque, and a controller configured to control the output adjustment mechanism based on the knock intensity. The controller executes a first control in which the output adjustment mechanism is controlled to reduce the knock intensity when the number of strong knocks that is the number of times the knock intensity becomes a second determination intensity or greater is a given determination number or less and when the knock intensity is greater than a first determination intensity, and executes a second control in which the output adjustment mechanism is controlled to reduce the maximum torque more than when the number of strong knocks is the determination number or less, when the number of strong knocks is greater than the determination number.

A control device for an engine is provided, which includes a knock intensity sensor configured to detect a knock intensity, an output adjustment mechanism configured to adjust an engine output torque, and a controller configured to control the output adjustment mechanism based on the knock intensity. The controller executes a first control in which the output adjustment mechanism is controlled to reduce the knock intensity when the number of strong knocks that is the number of times the knock intensity becomes a second determination intensity or greater is a given determination number or less and when the knock intensity is greater than a first determination intensity, and executes a second control in which the output adjustment mechanism is controlled to reduce the maximum torque more than when the number of strong knocks is the determination number or less, when the number of strong knocks is greater than the determination number.

An internal combustion engine includes an anisotropic thermal conductivity member (37, 51) provided on a wall surface defining a cylinder or a wall surface of a cooling water passage on a side of the cylinder, a thermal conductivity of the anisotropic thermal conductivity member in an axial direction of the cylinder being higher than a thermal conductivity of the anisotropic thermal conductivity member in a radial direction of the cylinder, and a thermally insulating member (38. 52) provided on an outer surface of the anisotropic thermal conductivity member with respect to the radial direction of the cylinder.

Methods and systems are disclosed for operating an engine that includes a knock control system that may determine contributions of individual noise sources to an engine background noise level. The contributions of the individual noise sources may be the basis for establishing the presence or absence of knock in one or more engine cylinders. The contributions of individual noise sources may be determined when engine cylinders are deactivated.

The present invention suppresses the worsening of stability due to a variation in EGR amounts between cylinders in a spark ignition engine. An engine control device for controlling a spark ignition engine equipped with an EGR means for recirculating exhaust gas in a combustion chamber and an air-fuel-ratio detection means for detecting the air-fuel ratio in each cylinder, the engine control device being characterized by being equipped with a means for changing the parameters for ignition control of a rich cylinder, when the air-fuel ratio of cylinders varies and there are richer cylinders and leaner cylinders relative to a prescribed air-fuel ratio during the execution of exhaust gas recirculation by the EGR means.

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.

Methods and systems are disclosed for operating an engine that includes a knock control system that may determine contributions of individual noise sources to an engine background noise level. The contributions of the individual noise sources may be the basis for establishing the presence or absence of knock in one or more engine cylinders. The contributions of individual noise sources may be determined when engine cylinders are deactivated.

A method of operating an internal combustion engine with at least one piston-cylinder unit, and preferably a plurality of the piston-cylinder units, whereby, in a detection mode of the internal combustion engine one or more knock-promoting measures are taken until knocking has occurred in at least one piston-cylinder unit, and the measure(s) is/are intensified until a termination criterion is reached, whereby it is detected in which of the piston-cylinder units knocking has occurred, and whereby, in piston-cylinder units detected as knocking, the ignition time for a normal operating mode of the internal combustion engine is retarded.

Provided is a vehicle control device with which improved fuel economy and lowered exhaust gas emissions can be effectively achieved without adversely affecting the driver when traveling while following a leading vehicle. The present invention has: a following-determination means that, during travel while following a leading vehicle, determines, on the basis of the speed of the host vehicle, the speed of the leading vehicle, and the distance from the leading vehicle, whether the host vehicle will be able to follow the leading vehicle by coasting; and an idle stop determination means that, when the following-determination means has determined that the host vehicle will be able to follow the leading vehicle by coasting, and the driving/travel state of the host vehicle satisfies other traveling idle stop criteria, determines that a traveling idle stop should be performed; and is provided with a determination criteria updating means for updating the determination criteria for the idle stop determination means in regard to criteria such as the leading vehicle characteristics, road surface conditions, and weather. In the event that it has been determined, from the determination conditions that have been updated in regard to the leading vehicle characteristics, etc., that following by coasting is possible, a control to shut off the on-board engine is performed.