Control system for internal combustion engine

摘要

A control system for an internal combustion engine wherein fuel injection timing is determined according to a detected engine operating condition. An actual ignition timing of the fuel is detected and an ignition delay correction amount is calculated wherein the actual ignition timing coincides with a target ignition timing set according to the engine operating condition. A cetane number of the fuel is estimated using a plurality of conversion tables for converting the ignition delay correction amount to the cetane number of the fuel. The fuel injection timing is corrected with the ignition delay correction amount. An exhaust gas recirculation control value map used for calculating a control value of the recirculation amount of exhaust gases is switched according to the estimated cetane number. The conversion table used for estimating the cetane number is switched according to the estimated cetane number.