Abstract: An internal combustion engine is provided in which a prescribed amount of fuel is injected over a predetermined period until an air-fuel ratio sensor is activated when fuel cut control of the internal combustion engine is stopped to resume normal engine operation. If an EGR gas is inducted immediately before the fuel cut control is started, the prescribed amount is reduced.

Abstract: In some cylinder deactivation modes (e.g. virtual V-four operation mode in which two cylinders of a V-six engine are deactivated), ignition/combustion may take place in operating cylinders at uneven intervals. In this case, the output torque varies between the immediately subsequent operating cylinders after the deactivated cylinders in the firing order and the other operating cylinders. A multicylinder engine includes an ignition timing adjustment unit. When the ignition takes place in the operating cylinders at uneven intervals during cylinder deactivation, the ignition timing adjustment unit adjusts ignition timing in each of the operating cylinders to smooth the output torque of the operating cylinders.

Abstract: When the amount of fresh air drawn into a combustion chamber is designated Ma and the amounts of exhaust gas recirculated into the combustion chamber by external and internal recirculation mechanisms are designated Megre and Megri, respectively, the exhaust gas recirculation rate (Regre) is defined as (Megre+Megri)/(Ma+Megre+Megri). The base ignition timing applied when Regr=0 is set based on the operating state of an internal combustion engine. An advance amount (IGad) is set such that the characteristic of an increase in IGad with respect to an increase in Regr is a downward convex characteristic. The ultimate ignition timing is set to a timing that is advanced from the base ignition timing by the advance amount (IGad).

Abstract: An internal combustion engine is provided in which a prescribed amount of fuel is injected over a predetermined period until an air-fuel ratio sensor is activated when fuel cut control of the internal combustion engine is stopped to resume normal engine operation. If an EGR gas is inducted immediately before the fuel cut control is started, the prescribed amount is reduced.

Abstract: A control device of an internal combustion engine includes: a target negative pressure setting section that set a target negative intake pipe pressure during cold acceleration to a negative intake pipe pressure larger than a negative intake pipe pressure prior to the cold acceleration; a throttle valve control section that controls a throttle valve so that the negative intake pipe pressure increases during cold acceleration; and an intake valve control section that controls a variable valve mechanism of an intake valve, based on the target negative intake pipe pressure, to obtain a target intake air amount.

Abstract: In some cylinder deactivation modes (e.g. virtual V-four operation mode in which two cylinders of a V-six engine are deactivated), ignition/combustion may take place in operating cylinders at uneven intervals. In this case, the output torque varies between the immediately subsequent operating cylinders after the deactivated cylinders in the firing order and the other operating cylinders. A multicylinder engine includes an ignition timing adjustment unit. When the ignition takes place in the operating cylinders at uneven intervals during cylinder deactivation, the ignition timing adjustment unit adjusts ignition timing in each of the operating cylinders to smooth the output torque of the operating cylinders.

Abstract: A control device of an internal combustion engine includes: a target negative pressure setting section that set a target negative intake pipe pressure during cold acceleration to a negative intake pipe pressure larger than a negative intake pipe pressure prior to the cold acceleration; a throttle valve control section that controls a throttle valve so that the negative intake pipe pressure increases during cold acceleration; and an intake valve control section that controls a variable valve mechanism of an intake valve, based on the target negative intake pipe pressure, to obtain a target intake air amount.