Charge-injected internal combustion engine, and method of operating same

Abstract

A charge-injected internal combustion engine exhibits improved starting performance with charge-injection timing control. A charge-injected internal combustion engine has an air-fuel injection valve for directly injecting a compressed air-fuel mixture into a combustion chamber. The engine is also provided with an air pump, driven by the crankshaft for discharging compressed air, and a timing controller for setting injection timing of the air-fuel injection valve. When initial startup of the engine is detected, the controller sets the injection timing to the intake stroke. When the engine reaches a predetermined engine speed, or when the pressure of the injection air reaches a threshold pressure where injection of the air-fuel mixture is possible on the compression stroke, the timing controller switches the injection timing from the intake stroke to the compression stroke.