PURPOSE: To prevent the occurrence of combustion at time of a rest cycle attributable to sticking fuel and an incomplete combustion in a combustion cycle afterward, by stopping the introduction of fresh air or mixture out of a suction passage to the full, during execution of cycle injection.
CONSTITUTION: When it is judged to be the specified light load driving area by a driving load state judging device A, fuel injection of a fuel injection valve G directly spraying fuel to a combustion chamber is controlled by a fuel injection controlling device B so as to cause a combustion cycle and a rest cycle to be repeated at the specified period. And, at time of execution of cycle injection by this fuel injection controlling device B, the shutter valve E installed in a suction passage at the downstream of a throttle valve is closed. And, at time of execution of the cycle injection, a control valve F, installed in an assist passage being synchronized with the fuel injection by the fuel injection valve G and its one end is opened between the throttle valve and the shutter valve E while the other end is opened to the vicinity of a nozzle of the fuel injection valve G, is opened.
YOSHIMURA TAKESHI
WAKUYA SHINICHI
