CONTROLLER FOR INTERNAL COMBUSTION ENGINE AND METHOD FOR CONTROLLING INTERNAL COMBUSTION ENGINE

A controller for an internal combustion engine includes processing circuitry. The processing circuitry executes a selecting process that selects one of a multi-injection process or a single injection process. The multi-injection process includes executing an intake synchronous injection and an intake asynchronous injection. The single injection process includes executing the intake asynchronous injection. In the intake synchronous injection, the fuel is injected in synchronization with a period in which an intake valve is open. In the intake asynchronous injection, the fuel is injected at timing advanced from timing of executing the intake synchronous injection. The processing circuitry changes ignition timing to a retarded side value in accordance with switching from execution of the multi-injection process to execution of the single injection process.