CONTROL METHOD AND CONTROL DEVICE FOR ENGINE

摘要

PROBLEM TO BE SOLVED: To suppress a reduction in learning opportunities while avoiding wrong learning of an alcohol concentration in an engine that can use alcohol-containing fuel.SOLUTION: A PCM 50: calculates the amount of unburned fuel that drops to an oil pan in an unburned state and is mixed into engine oil, out of fuel that is injected from an injector 11 for directly injecting fuel to a combustion chamber; calculates the amount of vaporized fuel that is vaporized from the engine oil caused by a temperature rise and is recirculated to an intake passage, out of the unburned fuel; calculates the amount of remaining fuel that remains in the engine oil within the oil pan by subtracting the amount of the vaporized fuel from the amount of the unburned fuel; and learns an alcohol concentration of the fuel injected from the injector 11 on the basis of an oxygen concentration in exhaust gas after confirmation that the amount of the remaining fuel is equal to or lower than threshold remaining amount.