Abstract: A multi-injection process includes performing intake synchronized injection in which fuel is injected in synchronism with an open valve period of an intake valve, and an intake asynchronous injection in which fuel is injected at a more advanced timing than during intake synchronized injection. A single-injection process includes injecting a required injection amount of fuel by intake asynchronous injection. An operating process includes operating a port injection valve for injecting fuel into an intake passageway. A selection process includes selecting the single-injection process if the temperature of an intake system of an internal combustion engine is not lower than a prescribed temperature, and selecting the multi-injection process if the temperature of the intake system is less than the prescribed temperature.

Abstract: A multi-injection process includes performing intake synchronized injection in which fuel is injected in synchronism with an open valve period of an intake valve, and an intake asynchronous injection in which fuel is injected at a more advanced timing than during intake synchronized injection. A single-injection process includes injecting a required injection amount of fuel by intake asynchronous injection. An operating process includes operating a port injection valve for injecting fuel into an intake passageway. A selection process includes selecting the single-injection process if the temperature of an intake system of an internal combustion engine is not lower than a prescribed temperature, and selecting the multi-injection process if the temperature of the intake system is less than the prescribed temperature.