摘要 |
A control apparatus for a cylinder-injection engine includes an electronic control unit which calculates an average effective pressure according to throttle opening and engine rotation speed, calculates an intake air amount per intake stroke according to an intake air amount detected by an airflow sensor and engine rotation speed, and calculates a volumetric efficiency based on the calculated intake air amount. A fuel injection amount is calculated according to an intake air amount and a target air-fuel ratio calculated based on a target average effective pressure when a compression-stroke injection mode is selected, and according to the intake air amount and a target air-fuel ratio calculated based on the volumetric efficiency when an intake-stroke injection mode is selected, whereby a fuel injection control is made based on the target air-fuel ratio suited to the injection mode, while managing the target air-fuel ratio, thereby always ensuring a proper combustion control and a stabilized engine operating state. During the changeover of injection mode, the target air-fuel ratio, determined for an injection mode before the changeover, is changed, at a speed which changes stepwise, to that determined for an injection mode after the changeover, whereby an engine torque change caused by a sudden change in fuel injection amount is suppressed to a minimum, thereby reducing a torque shock. |