Control system for internal combustion engine

A control system for an internal combustion engine having fuel injection means for injecting fuel into combustion chambers of said engine, said control system comprising:

• fuel property estimating means for estimating a fuel property based on a combustion state of the fuel injected into at least one cylinder of said engine;
• and
• fuel injection control means for controlling said fuel injection means so that a specific amount of fuel is injected into the at least one cylinder and an amount of fuel corresponding to an operating condition of said engine is injected into other cylinders not including the at least one cylinder,
• wherein said fuel injection control means performs an additional fuel injection after the fuel injection of the specific amount with respect to the at least one cylinder when at least one of the following conditions 1) to 3) is satisfied:
• 1) a demand torque of said engine is equal to or greater than a predetermined value;
• 2) a fuel injection amount corresponding to said other cylinders is equal to or greater than a predetermined amount;
• and
• 3) a torque difference parameter indicative of a difference between a torque generated by the at least one cylinder and a torque generated by said other cylinders is equal to or greater than a predetermined threshold value.