Patent ID: 7363912

Claim:
A fuel injection controller of a multi-cylinder engine, the fuel injection controller comprising: a learning condition determination device that determines whether a learning condition for performing injection for learning from an injector into a specific cylinder of the engine is satisfied; a learning injection command device that outputs a command injection amount to the injector to perform the injection for the learning into the specific cylinder when the learning condition is satisfied; an index value calculation device that calculates a difference between a rotation state of the engine in the case where the injection for the learning is performed and the rotation state of the engine in the case where the injection for the learning is not performed as a rotation speed index value; an injection amount calculation device that calculates an actual injection amount actually injected from the injector based on the rotation state of the engine; and an injection amount correction device that calculates a difference between the actual injection amount and the command injection amount outputted to the injector as a characteristic deviation and that corrects the command injection amount to decrease the characteristic deviation, wherein the index value calculation device calculates a plurality of rotation speed index values, and the injection amount correction device sets a lower degree of the correction of the command injection amount in the case where a variation in the rotation speed index values is equal to or greater than a specified value than a degree of the correction of the command injection amount in the case where the variation in the rotation speed index values is less than the specified value.