Fuel injection timing control apparatus and control method thereof for in-cylinder injection gasoline engine

摘要

A fuel injection mode is flexibly controlled according to the actual extent of adverse effects on an internal combustion engine from both deterioration of exhaust gas emissions and fuel dilution caused by fuel adhering to the piston top face and the cylinder inner peripheral face. A dilution degree counter value C is counted up when a coolant temperature at engine startup THWST and an intake air quantity sum value after engine startup GASUM are each equal to, or less than, respective predetermined values. A fuel dilution flag is set to "ON" when the dilution degree counter value C is equal to, or greater than, a predetermined value CH. A fuel injection timing of an intake stroke injection is changed to a timing on the advance side when this fuel dilution flag is "ON."