US Patent 7198031 Control device of internal combustion engine

An engine ECU executes a program including the steps of: selecting a map for a warm state or a map for a cold state based on an engine coolant temperature after an engine is started and rapid catalyst warm-up ends; calculating DI ratio r; calculating when to inject fuel from an intake manifold injector as time in synchronization with air intake if a load factor is equal to or greater than a threshold value and fuel is injected from injectors at a ratio predetermined therebetween; and otherwise calculating when to inject fuel from the intake manifold injector as during a period in which an intake valve is closed.