Abstract: When atmospheric pressure (Pa) which varies according to altitude is higher than a predetermined pressure threshold (Path) during idle operation in which catalyst warm-up request is issued, an intake pressure is controlled, through a throttle valve (19), to an intake pressure at which an intake air amount required to promote the warm-up of a catalyst converter (26) is obtained. When the atmospheric pressure (Pa) is lower than the predetermined pressure threshold (Path), the intake pressure is controlled, through a throttle valve (19), to an intake pressure (Pa?Pb) at which a differential pressure (Pb) required by a brake booster (8) is obtained. Accordingly, negative pressure in the brake booster (8) can be secured while promoting the warm-up of the catalyst during the idle operation.

Abstract: When atmospheric pressure (Pa) which varies according to altitude is higher than a predetermined pressure threshold (Path) during idle operation in which catalyst warm-up request is issued, an intake pressure is controlled, through a throttle valve (19), to an intake pressure at which an intake air amount required to promote the warm-up of a catalyst converter (26) is obtained. When the atmospheric pressure (Pa) is lower than the predetermined pressure threshold (Path), the intake pressure is controlled, through a throttle valve (19), to an intake pressure (Pa?Pb) at which a differential pressure (Pb) required by a brake booster (8) is obtained. Accordingly, negative pressure in the brake booster (8) can be secured while promoting the warm-up of the catalyst during the idle operation.

Abstract: In an internal combustion engine control device, a predetermined margin torque is set such that it is possible to maintain a predetermined engine idling speed by adjusting ignition timing with respect to load fluctuations during idling operation. The margin torque is set to decrease, as a load, acting on the internal combustion engine during idling operation, increases. Accordingly, the margin torque can be set to an appropriate value, and thus it is possible to improve a fuel economy performance during idling operation of the internal combustion engine.

Abstract: In an internal combustion engine control device, a predetermined margin torque is set such that it is possible to maintain a predetermined engine idling speed by adjusting ignition timing with respect to load fluctuations during idling operation. The margin torque is set to decrease, as a load, acting on the internal combustion engine during idling operation, increases. Accordingly, the margin torque can be set to an appropriate value, and thus it is possible to improve a fuel economy performance during idling operation of the internal combustion engine.