Toyota Jidosha Kabushiki Kaisha

Nippondenso Co., Ltd.

Mitsuharu Taura

Toshiaki Mizuno

Shinichi Abe

Hidetoshi Amano

The basic fuel injection time duration or the basic injector opening time is computed on the basis of an intake pressure and an engine speed. A start temperature correction value is selected on the basis of the engine temperature at the time of or immediately after the start up of the engine and attenuated in accordance with the time elapsed after the start up of the engine, such that, the lower the engine temperature is at the time of start up, the greater the start temperature correction value is. The rate of fuel injection rate is controlled by correcting the basic fuel injection time on the basis of the start temperature correction value and a condition of the engine.

Method and apparatus for controlling fuel injection rate in internal

Disclosed is a method of controlling the air-fuel ratio of an air-fuel mixture to be supplied to an internal combustion engine. The method employs a feedback control in which the control is made to maintain the air-fuel ratio at the stoichiometric level in accordance with the air-fuel ratio read through the detection of a component of the exhaust gas and, at least during the idling of the engine after the warming up of the same, a lean control in which the control is made to maintain the air-fuel ratio at the leaner side of the stoichiometric level. The lean control is allowed when the mean value of the engine speed over a predetermined period is greater than a predetermined reference value during the idling after warming up of the engine, while the feedback control is conducted when the mean value is below the predetermined reference value. Disclosed also is an apparatus suitable for carrying out this method.

Method and apparatus for controlling air-fuel ratio in internal

The amount of engine acceleration is detected as the amount of change in the absolute pressure in the intake passage, and an asynchronous fuel injection is conducted regardless of the crank position as the amount of acceleration exceeds a predetermined reference value. In ordinary state of engine operation, the synchronous fuel injection is conducted in synchronism with the crank rotation such that the air-fuel ratio of the mixture coincides with the stoichiometric one, upon sensing the air-fuel ratio from the content of oxygen remaining in the exhaust gas. The mixture is made richer or leaner than the stoichiometric one in accordance with the state of operation of the engine. The judging level for the judgement as to whether the asynchronous fuel injection is necessary or not is increased or decreased in accordance with the air-fuel ratio so that the asynchronous fuel injection is conducted taking into account also the air-fuel ratio.

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Toyota, Japan

Mitsuharu Taura