| 摘要 |
In response to a switching demand from an all-cylinder operation to a reduced-cylinder operation, the amount of air to be taken into each of cylinders 2A to 2D is made larger than the amount of air during the ail-cylinder operation in a normal state. Preparatory control of changing the ignition timing of ignition device to a timing on the retard side with respect to the ignition timing during the all-cylinder operation in the normal state is executed. After termination of the preparatory control, the reduced-cylinder operation is started. During execution of the preparatory control, the valve closing timing of an exhaust valve 9 is changed to a timing on the advance side with respect to the valve closing timing thereof during the all-cylinder operation in the normal state so as to reduce the amount of internal EGR gas in at least a part of an operating range C. |
