Method and systems are provided for, in response to a state of charge (SOC) of a vehicle battery increasing above a threshold SOC, reducing an alternator charging based on one or more of a spark timing, an engine speed, an air-fuel ratio, and an engine load. In this way, fuel consumption may be reduced while maintaining a battery SOC for operation of front-end accessories may be achieved, and fuel consumption may be reduced during aggressive vehicle driving conditions such has high engine loads near transmission downshift thresholds and high engine speeds.

An internal combustion engine includes a twin entry type turbocharger with which a first exhaust passage and a second exhaust passage respectively communicate individually, a communication path that causes the first exhaust passage and the second exhaust passage to communicate with each other, a communication valve that opens and closes the communication path, an abnormality diagnosis device that diagnoses presence or absence of abnormality of the communication valve, a variable valve timing mechanism capable of changing a period of valve overlap of the engine, and a control device. When it is determined that abnormality of a valve closure failure of the communication valve is present, the control device operates the mechanism to reduce the valve overlap in an operating state in which the communication valve is closed, more than in a case where it is determined that abnormality of a valve closure failure of the communication valve is absent.

A control system of an internal combustion engine which performs diffusion combustion by compression autoignition on fuel injected in a main injection in at least a partial operating range and which performs stratified combustion by spark ignition using a spark plug on fuel injected prior to the main injection. The control system determines whether or not the diffusion combustion occurs and performs combustion by spark ignition using the spark plug on the fuel injected in the main injection when it is determined that the diffusion combustion does not occur.

A control system of an internal combustion engine which performs diffusion combustion by compression autoignition on fuel injected in a main injection in at least a partial operating range and which performs stratified combustion by spark ignition using a spark plug on fuel injected prior to the main injection. The control system determines whether or not the diffusion combustion occurs and performs combustion by spark ignition using the spark plug on the fuel injected in the main injection when it is determined that the diffusion combustion does not occur.

An engine control system for a vehicle includes a target torque module that determines a target torque output of an engine based on at least one driver input. A target air per cylinder (APC) module determines a target APC for the engine based on the target torque. A target mass airflow (MAF) module determines a target MAF through a throttle valve of the engine based on the target APC, a number of activated cylinders of the engine, and a total number of cylinders of the engine. A throttle control module determines a target throttle opening based on the target MAF and controls opening of the throttle valve based on the target throttle opening.

An engine control system for a vehicle includes a target torque module that determines a target torque output of an engine based on at least one driver input. A target air per cylinder (APC) module determines a target APC for the engine based on the target torque. A target mass airflow (MAF) module determines a target MAF through a throttle valve of the engine based on the target APC, a number of activated cylinders of the engine, and a total number of cylinders of the engine. A throttle control module determines a target throttle opening based on the target MAF and controls opening of the throttle valve based on the target throttle opening.

In at least some implementations, a method of controlling engine idle speed includes comparing engine speed to a speed threshold where the speed threshold may include a range of speeds, if the engine speed is outside of the speed threshold, adjusting the timing of an ignition spark up to a threshold amount of ignition timing adjustment, and if the engine speed is not within said speed threshold after adjustment up to the threshold amount of ignition timing adjustment then adjusting the air/fuel mixture provided to the engine to bring the engine speed within said speed threshold.

In at least some implementations, a method of controlling engine idle speed includes comparing engine speed to a speed threshold where the speed threshold may include a range of speeds, if the engine speed is outside of the speed threshold, adjusting the timing of an ignition spark up to a threshold amount of ignition timing adjustment, and if the engine speed is not within said speed threshold after adjustment up to the threshold amount of ignition timing adjustment then adjusting the air/fuel mixture provided to the engine to bring the engine speed within said speed threshold.

An apparatus of controlling a vehicle and a method thereof are provided. The operating region of an engine is operated with theoretical air-fuel ratio. The apparatus includes a supercharger that supplies compressed air to a the combustion chamber of the engine and a spark plug that ignites mixed air supplied to the combustion chamber. An intake valve selectively opens and closes the combustion chamber for inflowing the mixed air therein. A variable valve apparatus adjusts an opening timing and closing timing of the intake valve and a controller adjusts an ignition timing of the spark plug and the closing timing of the intake valve through the variable valve apparatus based on the operating region of the engine.

A handheld work apparatus has a combustion engine (4) for driving a tool. The combustion engine (4) has an ignition device, a device for metering fuel and a control device (31). The control device (31) engages when an engagement speed (n.sub.E1, n.sub.E2) is reached, in order to limit the speed (n) of the combustion engine (4). In order to allow the speed (n) to be set in an easy manner at full throttle, the work apparatus has a device for setting the engagement speed (n.sub.E2) by the user.