Engine controller and engine controlling method

An engine controller, comprising:

• a fuel injection corrector configured to perform a cylinder-by-cylinder correction of a fuel injection amount so as to cause differences among air-fuel ratios of air-fuel mixture burned in a plurality of cylinders,
• wherein fuel injection corrector includes circuitry that is configured such that, in a case in which the cylinder-by-cylinder correction of the fuel injection amount results in a cylinder in which combustion is performed at an air-fuel ratio richer than an output air-fuel ratio, the output air-fuel ratio being an air-fuel ratio at which combustion torque is maximized, the circuitry performs a cylinder-by-cylinder correction of ignition timing such that the ignition timing of the cylinder in which combustion is performed at the air-fuel ratio richer than the output air-fuel ratio becomes more advanced than the ignition timing of other cylinders.

An engine controlling method, comprising:

• performing a cylinder-by-cylinder correction of a fuel injection amount so as to cause differences among air-fuel ratios of air-fuel mixture burned in a plurality of cylinders;
• and
• in a case in which the cylinder-by-cylinder correction of the fuel injection amount results in a cylinder in which combustion is performed at an air-fuel ratio richer than an output air-fuel ratio, which is an air-fuel ratio at which combustion torque is maximized, performing a cylinder-by-cylinder correction of ignition timing such that the ignition timing of the cylinder in which combustion is performed at the air-fuel ratio richer than the output air-fuel ratio becomes more advanced than the ignition timing of other cylinders.