PURPOSE: To control an engine in an optimum way by detecting the change of the atmospheric condition indirectly from the change of the ignition timing and changing the maximum injecton quantity and EGR quantity in response to this change.

CONSTITUTION: The ignition timing is determined from signals of an ingition timing sensor 114 provided in an engine combustion chamber and a crank angle sensor 116. The fuel injecton timing is feedback-controlled by using this ignition timing. Since the signal applied to an injecton timing control actuator 94 indicates the atmospheric condition, the maximum injection quantity and EGR quantity are controlled in response to this signal. Accordingly, the engine can be controlled in an optimum way even if the atmospheric condition is changed.