A control device for an internal combustion engine including an in-cylinder injection fuel injection valve, and a port injection fuel injection valve, has a controller that controls injection amount ratios of the in-cylinder injection fuel injection valve and the port injection fuel injection valve in accordance with a driving condition of the engine. A fuel cut is performed at a predetermined deceleration of the internal combustion engine. The injection amount ratio of the in-cylinder injection fuel injection valve is corrected to be decreased at a fuel cut recovery at which a fuel supply is restarted from the fuel cut state, during a predetermined period from the start of the recovery.

A diesel engine, in particular a high-power diesel engine, which has a variable valve train including an adjusting unit for adjusting a valve opening time, a valve lift, a camshaft phase position and/or a valve steering, and a control or regulating unit for controlling the adjusting unit. The control and/or regulating unit includes at least one operational mode provided for starting the engine when the engine is at a low temperature, in which the control and/or regulating unit is provided to adjust the valve opening time, at least during a preliminary phase for at least one inlet valve, which overlaps at least with one compression stroke of an associated cylinder, and to interrupt an injection of fuel at least into the cylinder associated with the inlet valve. The invention also relates to a method for starting such a diesel engine.

For exhaust gas recirculation (EGR) fueling control, at least one donor cylinder of a plurality of cylinders in an engine provides exhaust gas to an air intake for the plurality of cylinders. A fuel variable restriction initially provides fuel concurrent with an intake stroke for the at least one donor cylinder in response to a transition from withholding the fuel to the plurality of cylinders.

An internal combustion engine mounted on a vehicle includes an exhaust passage provided with a catalyst. A controller for the internal combustion engine includes a processor. The processor is configured to perform an auto-stopping process on the engine when the engine is idling, perform an auto-restarting process on the engine when the engine is automatically stopped, correct an amount of fuel injected into the engine so that the fuel injection amount of the engine is increased by a correction amount after the auto-restarting process is started, and change the correction amount in accordance with an amount of oxygen stored in the catalyst at a point of time when the auto-stopping process is started.

Methods and arrangements for transitioning an engine between a deceleration cylinder cutoff (DCCO) state and an operational state are described. In one aspect, transitions from DCCO begin with reactivating cylinders to pump air to reduce the pressure in the intake manifold prior to firing any cylinders. In another aspect, transitions from DCCO, involve the use of an air pumping skip fire operational mode. After the manifold pressure has been reduced, the engine may transition to either a cylinder deactivation skip fire operational mode or other appropriate operational mode. In yet another aspect a method of transitioning into DCCO using a skip fire approach is described. In this aspect, the fraction of the working cycles that are fired is gradually reduced to a threshold firing fraction. All of the working chambers are then deactivated after reaching the threshold firing fraction.

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.

An internal combustion engine comprises an exhaust purification catalyst and a downstream side air-fuel ratio sensor which is arranged at a downstream side of the exhaust purification catalyst. A control system can perform fuel cut control which stops the feed of fuel to the internal combustion engine during operation of the internal combustion engine, and, after the end of fuel cut control, performs post-return rich control which sets the exhaust air-fuel ratio to a rich air-fuel ratio. The control system correct the output air-fuel ratio of the downstream side air-fuel ratio sensor, based on a difference between the stoichiometric air-fuel ratio and the output air-fuel ratio in the output stabilization time period, which is a time period when the amount of change per unit time of the output air-fuel ratio of the downstream side air-fuel ratio sensor is a predetermined value or less, in the time period after the end of the fuel cut control and before the output air-fuel ratio of the downstream side air-fuel ratio sensor becomes a rich judged air-fuel ratio or less.

A control system comprising a variable valve timing mechanism (B) able to set a closing timing of an intake valve (7), a fuel injector (13) for feeding fuel to a combustion chamber (5), an intake air amount detector (17) for detecting an amount of intake air fed to an intake passage from the outside air, and a pressure sensor (16) for detecting the pressure in the intake passage downstream of a throttle valve (16). When air in the combustion chamber (5) is blown back to the intake passage when injection of fuel is restarted after the fuel injection is stopped at the time of deceleration operation, the basis for calculation of the fuel injection amount in the initial cycle when fuel injection is restarted is switched from the amount of intake air detected by the intake air amount detector (17) to the pressure in the intake passage detected by the pressure sensor (18).

Methods and arrangements for transitioning an engine between a deceleration cylinder cutoff (DCCO) state and an operational state are described. In one aspect, transitions from DCCO begin with reactivating cylinders to pump air to reduce the pressure in the intake manifold prior to firing any cylinders. In another aspect, transitions from DCCO, involve the use of an air pumping skip fire operational mode. After the manifold pressure has been reduced, the engine may transition to either a cylinder deactivation skip fire operational mode or other appropriate operational mode. In yet another aspect a method of transitioning into DCCO using a skip fire approach is described. In this aspect, the fraction of the working cycles that are fired is gradually reduced to a threshold firing fraction. All of the working chambers are then deactivated after reaching the threshold firing fraction.

In a control device for an internal combustion engine, when a fuel-supply cutoff process ends and fuel injection restarts, an increase ratio based on which a base injection amount is increased is set such that the increase ratio when a duration of the fuel-supply cutoff process is long is higher than the increase ratio when a duration of the fuel-supply cutoff process is short. In addition, the increase ratio is decreased with a lapse of time after fuel injection restarts. Further, a decrease rate that is an amount by which the increase ratio is decreased within a prescribed period of time is set such that the decrease rate in the case where the duration of the fuel-supply cutoff process is long is higher than the decrease rate in the case where the duration of the fuel-supply cutoff process is short.