Fuel injection control system for engine

A fuel injection control system for an engine including a fuel injection valve, said fuel injection control system comprising:

• means for calculating a required fuel amount during a predetermined calculation cycle and for calculating a injected fuel amount to be injected from the fuel injection valve on the basis of the required fuel amount;
• means for calculating, after a fuel injection of a fuel from the fuel injection valve on the basis of the calculated injected fuel amount, a lack of fuel amount immediately before a re-calculation of a required fuel amount during the calculation cycle at the end of an intake stroke, said lack of fuel amount being calculated by subtracting the calculated injected fuel amount from the re-calculated required fuel amount;
• said lack of fuel amount being additionally injected during the intake stroke;
• said lack of fuel injection amount being calculated by addition of a fuel injected from the fuel injection valve and deposited on an inner wall of an intake pipe to achieve a first amount, and subtracting a fuel released from the deposited fuel to flow into an engine cylinder from the first amount.

A fuel injection control system for an engine comprising:

• at least one engine cylinder;
• a throttle valve;
• at least one upstream injection valve being disposed in an upstream position with respect to the throttle valve;
• at least one downstream injection valve being disposed in a downstream position with respect to the throttle valve;
• a direct fuel flow calculating unit;
• an indirect fuel flow calculating unit;
• a downstream fuel calculating unit, said downstream fuel calculating unit outputting a combined fuel flow from the upstream position and said downstream injection valve;
• a downstream direct fuel flow calculating unit;
• a downstream indirect fuel flow calculating unit;
• an adding unit, said adding unit outputting an actual fuel amount to said cylinder;
• and
• a comparison unit, said comparison unit calculating a lack of fuel amount immediately before recalculating a recalculated required fuel amount at a calculation cycle coming at the end of an intake stroke of said cylinder, said lack of fuel amount being calculated by subtracting a sum of a required fuel amount and said actual fuel amount from the recalculated required fuel amount.