Abstract: An internal combustion engine exhaust gas recirculation valve control apparatus which, during exhaust gas recirculation (EGR) control, can correct positional error due to stepping out of a stepping motor actuating an exhaust gas recirculation valve and effect EGR control with increased accuracy. A controller initializes the stepping motor during EGR control when the target opening degree of the exhaust gas recirculation valve becomes `fully closed` by driving the stepping motor to cause a valve body to abut a valve seat.

Abstract: An apparatus capable of performing correct determination of a misfire limit without involving influence by differences between individual internal combustion engines, and thus capable of realizing highly precise lean control. During lean control, a mean deviation MD.sub..lambda.=1 of angular-velocity differences, which has been learned during the adoption of the stoichiometric air-fuel ratio (i.e., during .lambda.=1) in the relevant internal combustion engine, is subtracted from the current mean deviation MD.sub.L of angular-velocity differences occurring in the engine, so that the fuel injection amount is corrected in accordance with the resultant difference .DELTA.MD, which is attributable to an increase in the risk of misfire. Thus, the mean deviation component MD.sub..lambda.=1 which corresponds to the stoichiometric air-fuel ratio and which may differ between individual internal combustion engines, is eliminated, and only the component .DELTA.

Abstract: In a lean burn control system for an internal combustion engine, when surging in the engine is caused due to lowering of an engine lean limit, a first correction circuit decreases a target air-fuel ratio irrespective of whether the system is operated under an open loop control or a feedback control. On the other hand, when the surging is caused due to variation in output characteristic of an air-fuel ratio monitoring sensor, a second correction circuit decreases the target air-fuel ratio only when the system is operated under the feedback control. Accordingly, the target air-fuel ratio as corrected by the first correction circuit is used in the open loop control, while the target air-fuel ratio as corrected by the first and second correction circuits is used in the feedback control.

Abstract: A fuel injection device increases an increment value of fuel after cut-off of assist air so that the air/fuel ratio for combustion can be held constant to stabilize the idling rotational speed. The device has control means for controlling, based on various detection signals indicative of an engine cooling water temperature, an engine rotational speed, an amount of intake air, etc., a valve-opening time of a fuel injection valve in accordance with a predetermined control program, and also controlling an on/off control valve for cutting off air supplied to fuel atomizing means. Fuel incrementing means increases an amount of liquid fuel supplied to the fuel injection valve depending on opening/closing of the on/off control valve and the temperature of engine cooling water. When the on/off control valve is closed and an engine is in a state of steady operation, the increment value of the liquid fuel supplied to the fuel injection valve can be gradually increased by the fuel incrementing means.

Abstract: A fuel feed apparatus of an internal combustion engine comprises: a passage member which is formed with a fuel passage serving to direct fuel injected from a fuel injection valve toward respective intake valves of the internal combustion engine, assist air passage through which assist air is jetted so as to cross the fuel injected from the fuel passage, and a cylindrical guide portion serving to regulate a spray cone angle of the fuel when the assist air is jetted from the assist air passages; and an interrupter device for interrupting the supply of the assist air to the air assist passages in accordance with the operating condition of the internal combustion engine, so that sprays of fuel directed to the plurality of intake valves individually are formed by the fuel passage when the interrupter device cuts off the assist air, while a single spray of fuel atomized by the assist air the spray cone angle of which is regulated by the guide portion is formed when the interrupter device allows the assist air to be