Controller for internal combustion engine, control method for internal combustion engine, and memory medium

A control method for an internal combustion engine, wherein

• the internal combustion engine in which the control method is performed includes:
• cylinders;
• port injection valves that inject fuel into intake ports;
• and
• direct injection valves that inject fuel into the cylinders, and
• the control method comprises:
• changing a port injection ratio according to an engine operating state of the internal combustion engine, the port injection ratio being a ratio of a port injection amount that is an amount of fuel injected by the port injection valves to an amount of fuel supplied to the cylinders from the port injection valves and the direct injection valves;
• executing an injection reducing process that causes a fuel injection amount in a reduced-injection cylinder to be smaller than a fuel injection amount in other cylinders, the reduced-injection cylinder being one or some of the cylinders;
• and
• limiting increases in an adhered fuel amount in the intake ports by regulating the port injection ratio during execution of the injection reducing process.

A non-transitory computer readable medium that stores a program that causes a processor to execute a control process for an internal combustion engine, wherein

• the internal combustion engine for which the control process is executed includes:
• cylinders;
• port injection valves that inject fuel into intake ports;
• and
• direct injection valves that inject fuel into the cylinders, and
• the control process includes:
• changing a port injection ratio according to an engine operating state of the internal combustion engine, the port injection ratio being a ratio of a port injection amount that is an amount of fuel injected by the port injection valves to an amount of fuel supplied to the cylinders from the port injection valves and the direct injection valves;
• executing an injection reducing process that causes a fuel injection amount in a reduced-injection cylinder to be smaller than a fuel injection amount in other cylinders, the reduced-injection cylinder being one or some of the cylinders;
• and
• limiting an increase in an adhered fuel amount in the intake ports by regulating the port injection ratio during execution of the injection reducing process.