A control device for an internal combustion engine executes an automatic stop control and automatic start-up control for an intermittent operation of the internal combustion engine. In the automatic start-up control, the control device is configured to commence a restart by starting fuel injection from a fuel-injection-start cylinder. In the automatic stop control, the control device is configured to: execute an air-fuel-ratio rich processing that controls an air-fuel ratio such that the air-fuel ratio becomes richer than the stoichiometric air-fuel ratio before a start of the fuel cut; execute a throttle closing processing that closes a throttle valve in synchronization with the fuel cut; and execute a throttle opening processing approaches the atmospheric air pressure before a cylinder destined to be the fuel-injection-start cylinder later completes the last intake stroke in the course of the engine stop after execution of the throttle closing processing.

The invention relates to a method for starting an internal combustion engine for a motor vehicle, said internal combustion engine having at least two cylinders, a valve drive with at least one inlet valve and at least one outlet valve for each of the cylinders, wherein at least the closing times of the inlet valves can be variably adjusted, and a direct injection system, in particular a gasoline direct injection system, the starting process being initiated by a direct injection and ignition in one of the cylinders. During a starting process, the closing time of at least one inlet valve differs from at least one of the other cylinders dependent on at least one current state value.

A method of implementing start-stop in an internal combustion engine, the engine having exhaust gas recirculation (EGR) from at least one dedicated EGR (D-EGR) cylinder. For stopping the engine, the camshaft is locked, and a hydraulic cam phaser is used to cushion the engine inertia. The engine is stopped such that one of the D-EGR cylinders is in top-dead center position. For starting the engine, that D-EGR cylinder is fuel-injected, and exhaust bleed-off performed if necessary.

An engine control device for a saddle riding vehicle includes a mechanical centrifugal clutch for connecting and disconnecting driving force from an engine to a driving wheel, a throttle operator to adjust output power of the engine, a motor to rotate a crankshaft of the engine, and a control unit to control the motor and a fuel injection system. The control unit executes injection stopping control for stopping fuel injection during deceleration of the vehicle and executes, when an opening operation of the throttle operator is performed after an engine speed becomes equal to or lower than a centrifugal clutch disconnection speed at which the centrifugal clutch is disconnected, acceleration assist control for rotating the crankshaft with the motor.

Apparatuses, methods, and systems for starting an internal combustion engine under cold start conditions are disclosed. A combustible mixture is supplied to a plurality of cylinders of the internal combustion engine, where a number of ignition devices are operably connected with less than all of the plurality of cylinders so that at least one of the plurality of cylinders does not include an ignition device. In one form, only one ignition device is included in a bank of cylinders. In response to a cold start condition, a spark by the plurality of ignition devices is generated to cause ignition of the combustible mixture and start the internal combustion engine. In response to a normal or non-cold starting condition, the internal combustion engine is started by compression ignition where none of the ignition devices generate a spark.

A control device is provided for controlling a vehicle that includes: an internal combustion engine having a fuel injection valve, an ignition device and an in-cylinder pressure sensor; and an electric motor configured to rotate to drive a crankshaft of the internal combustion engine. The control device is configured, when an assist torque is applied to the crankshaft by means of the electric motor, to perform an ignition start-up operation that starts fuel injection and ignition from an expansion stroke cylinder to start up the internal combustion engine. The assist torque is a torque by which the crankshaft is not caused to rotate, and is greater when an in-cylinder pressure in a compression stroke cylinder is higher.

A method for starting an internal combustion engine of a motor vehicle includes detecting before a direct starting of the internal combustion engine that a piston which is disposed translationally moveably in a start cylinder of the internal combustion engine is in an upper half of, or in a middle of, a stroke of the piston. In response to the detecting, rotating an output shaft of the internal combustion engine in a direction of rotation of the output shaft such that the piston is in a lower half of the stroke of the piston and in an intermediate position. The method further includes rotating the output shaft in a second direction of rotation before and/or during fuel being first directly injected into the start cylinder such that the piston is moved out of the intermediate position in a direction of an upper dead center of the piston.

A method of implementing control logic of a compression-ignition engine is provided. A controller outputs a signal to a injector and a variable valve operating mechanism so that a gas-fuel ratio (G/F) becomes leaner than a stoichiometric air fuel ratio, and an air-fuel ratio (A/F) becomes equal to or richer than the stoichiometric air fuel ratio, and to an ignition plug so that unburnt mixture gas combusts by self-ignition after the ignition plug ignites mixture gas inside a combustion chamber. The method includes steps of determining a geometric compression ratio and determining the control logic defining an intake valve close timing IVC. IVC (deg.aBDC) is determined so that the following expression is satisfied: if the geometric compression ratio is 10<17,

0.4234.sub..sup.222.926.sub.+207.84+CIVC0.4234.sub..sup.2+22.926.sub.167.84+C

where C is a correction term according to an engine speed NE (rpm),

C=3.310.sup.10NE.sup.31.010.sup.6NE.sup.2+7.010.sup.4NE.

A start control system for an engine is provided. The engine is a direct injection engine, and the engine is provided with a starter motor. The start control system includes an electronic control unit. The electronic control unit is configured to execute fuel injection and ignition in a cylinder in an expansion stroke so as to start the engine without using the starter motor, when the electronic control unit determines that a restart condition of the engine is satisfied immediately before the engine is stopped. The electronic control unit is configured to control an ignition delay time based on at least one of a rotational direction and a rotational speed of a crankshaft, during execution of the fuel injection. The ignition delay time is a period of time from fuel injection into the cylinder in the expansion stroke to ignition.

When a crankshaft reversely rotates immediately before a stoppage of an engine, the amount of fuel injection in a cylinder in an expansion stroke is controlled to acquire a target air-fuel ratio in accordance with the amount of air in the cylinder. When the electronic control unit determines that the exhaust valve is opened at the time of reverse rotation, the amount of fuel injection is determined by considering a change in the amount of air due to exchange of gas with an exhaust path.