Patent ID: 7146964

Claim:
An engine control system comprising: a cylinder pressure sensor detecting pressure in a combustion chamber of an engine; and an electronic control unit feedback-controlling a control subject which relates to an engine control based on a detected value by the cylinder pressure sensor, wherein the electronic control unit includes: a heat-release-rate calculation means for calculating a heat-release-rate in the combustion chamber of the engine based on an output signal from the cylinder pressure sensor; a combustion mode determining means for determining whether a combustion mode of the engine is a first combustion mode or a second combustion mode in which a initial rising inclination of the heat-release-rate relative to a time axis or a crank angle is more moderate than that in the first combustion mode; a first feedback control means activated when the combustion mode is the first combustion mode, the first feedback control means deriving an ignition timing in which the calculated heat-release-rate exceeds a predetermined ignition determining value, the first feedback control means feedback-controlling the control subject based on the ignition timing; and a second feedback control means activated when the combustion mode is the second combustion mode, the second feedback control means deriving a peak arising timing of the calculated heat-release-rate, the second feedback control means feedback-controlling the control subject based on the peak arising timing.