A diesel engine of the present invention includes a turbocharger including: a turbine provided on an exhaust passage; a compressor provided on an intake passage; and a plurality of nozzle vanes provided around the turbine to control a flow velocity of an exhaust gas colliding with the turbine, angles of the nozzle vanes being changeable. In a case where a ratio of a volume of a combustion chamber when the intake valve is closed to a volume of the combustion chamber when a piston is located at a top dead center is denoted by an effective compression ratio ε.sub.e, and a total displacement of the engine is denoted by V (L), the effective compression ratio ε.sub.e is set to satisfy Formula (1) “−0.67×V+15.2≦ε.sub.e≦14.8.”

The present invention relates to a control apparatus and method for an internal combustion engine including two fuel injection valves in the intake port of each cylinder. In the present invention, fuel injection from a first fuel injection valve is activated while fuel injection from a second fuel injection valve is temporarily stopped at the resumption of fuel injection from the deceleration fuel cut-off state in response to a decrease in the engine rotation speed. The amount of minimum fuel injection to each cylinder that ensures the accuracy of fuel measurement can be reduced, and fuel is injected from the first fuel injection valve in an amount equal to or greater than the amount of minimum fuel injection. Thus, fuel injection can be resumed at a lower engine speed than when fuel injection is resumed from the two fuel injection valves.

The present invention relates to a control apparatus and method for an internal combustion engine including two fuel injection valves in the intake port of each cylinder. In the present invention, fuel injection from a first fuel injection valve is activated while fuel injection from a second fuel injection valve is temporarily stopped at the resumption of fuel injection from the deceleration fuel cut-off state in response to a decrease in the engine rotation speed. The amount of minimum fuel injection to each cylinder that ensures the accuracy of fuel measurement can be reduced, and fuel is injected from the first fuel injection valve in an amount equal to or greater than the amount of minimum fuel injection. Thus, fuel injection can be resumed at a lower engine speed than when fuel injection is resumed from the two fuel injection valves.

A fuel property determination apparatus for an internal combustion engine is applied to an internal combustion engine that is equipped with an ignition plug and an ignition timing controller. An electronic control unit provided in the fuel property determination apparatus executes a determination process of making a determination on a property of a fuel supplied to the internal combustion engine based on an ignition sufficiency ratio, during a predetermined period after startup of the internal combustion engine. The electronic control unit is configured to determine that the property of the fuel is heavy when a determination index value that is obtained by subjecting the ignition sufficiency ratio to a smoothing process is equal to or larger than a predetermined threshold. The electronic control unit is configured to set a smoothing coefficient to a value corresponding to each of a first period, a second period, and a third period.

A method for managing the mass of fuel injected into the cylinder of an internal combustion engine fed by direct injection. The pressure and the pressure drop per unit of time are monitored (13) during the starting phase. If the pressure becomes too low (7), or if it drops too quickly (9), the mass of fuel injected on each cycle is adjusted (15) in order to maintain a high fuel pressure in the injector (37). The method can be applied, for example, in the event of low-temperature starting using any type of fuel, for example pure or mixed ethanol.

Methods and systems are provided for operating a cylinder of an engine including a pre-chamber ignition system during a cold start condition. In one example, a method may include performing a post-injection in the cylinder, and then performing a pre-chamber combustion during an exhaust stroke of the cylinder. In this way, a temperature of a catalyst of the engine may be increased, which may decrease vehicle emissions during the cold start condition.

A method to reduce during the start of an engine undesired emissions from the engine, where an SCR catalytic converter for the cleaning of exhaust gases is arranged in an exhaust passage at the engine. The method includes controlling the dosage of fuel to the engine with a certain delay relative to what is the case during essentially optimal combustion in order to reduce the development of heat that results from the combustion of fuel through non-optimal combustion. Also a computer program product comprising program code to implement a method of reducing emissions. Also an arrangement to reduce during the start of an engine undesired emissions from the engine and a motor vehicle that is equipped with the arrangement.

Disclosed are a vehicle and an engine control method for more conveniently restarting an engine in the state in which a function of automatically turning off the engine is activated during braking for improving fuel efficiency. The engine control method includes turning off an engine through an idle stop and go (ISG) system during braking due to manipulation of a brake pedal, determining whether at least one preset starting condition is satisfied based on information on a forward environment, and turning on the engine irrespective of whether manipulation of the brake pedal is released when any one of the at least one starting condition is satisfied.

The invention relates to a control device for an internal combustion engine using the center-of-gravity position of a heat generation rate for combustion control. This control device controls the center-of-gravity position of a heat generation rate to correspond to a reference position in a case where an engine cooling water temperature is equal to or higher than a reference cooling water temperature and controls the center-of-gravity position of a heat generation rate to correspond to a crank angle further on an advance side than the reference position in a case where the engine cooling water temperature is lower than the reference cooling water temperature.

At the time of starting up an engine (9) using an assist motor generator (10), a main controller (28) lowers a lower limit value in a charge/discharge range of an electricity storage device (19) from a first lower limit value (min1) to a second lower limit value (min2) through an energy management control part (28B). The main controller (28) heightens the lower limit value in the charge/discharge range of an electricity storage device (19) from the second lower limit value (min2) to the first lower limit value (min1) when the start of the engine (9) is completed. Further, the main controller (28) displays engine stop prohibition information on a display device (30) when the start of the engine (9) is completed and when an SOC of the electricity storage device (19) falls below the first lower limit value (min1).