Control system for internal combustion engine

摘要

A control system for an internal combustion engine having a fuel injection valve. A fuel injection timing is determined according to the detected engine operating condition. A target ignition timing of the fuel is calculated using a plurality of maps that store the target ignition timings according to the engine operating condition and an actual ignition timing of the fuel is detected. An ignition delay of the actual ignition timing with respect to the target ignition timing is calculated. The cetane number of the fuel is estimated according to the calculated ignition delay. The map to be used in calculating the target ignition timing is switched according to the estimated cetane number.