Abstract: An engine control system derives a basic fuel supply amount on the basis of preselected parameters including an intake air volume associated value and modifies the derived basic fuel supply amount in such a manner that the modified fuel supply amount becomes equal to the basic fuel supply amount derived on the basis of the preselected parameters when the engine is not in an acceleration state satisfying a predetermined first condition, and the modified fuel supply amount varies at a greater rate than variation rate of the basic fuel supply amount derived on the basis of the preselected parameters when the engine is in the accelerating state satisfying the predetermined first condition. The basic fuel supply amount as modified may be further modified with a correction value during the engine accelerating state satisfying a predeermined second condition.

Abstract: A fuel supply control system introducing the feature of learning in assuming or projecting an intake air flow rate while an engine driving condition is maintained in a sonic flow range, in which intake air path area is maintained substantially constant and intake air flow rate is varied linearly according to variation of an engine speed. The system also detects the engine driving condition in the sonic flow range and the engine speed maintained substantially constant to derive a basic fuel supply amount on the basis of boost pressure. The assumed intake air flow rate is derived on the basis of the basic fuel supply amount and the engine speed. The system derives the basic fuel supply amount on the basis of the assumed intake air flow rate and the engine speed when the engine speed varies within the sonic flow range.

Abstract: A fuel injection control system derives a correction coefficient for compensating overshooting component in measurement of an engine load indicative parameter, such as an intake air flow rate. The correction coefficient may be variable in such a manner that it increases according to increasing of the engine load. The correction coefficient may be used for correcting either the measured engine load parameter or the fuel injection amount derived taking the measured engine load.

Abstract: An engine control system introduces a technology of assuming actually required fuel amount to be delivered to each engine cylinder at opening timing of an intake valve of the engine cylinder. In order to derive the assumed fuel demand, a basic fuel supply amount is derived on the basis of a basic fuel supply control parameter including an engine speed data and an intake air amount representative data, an air induction path area variation ratio data and a lag time data from derivation of the air induction path area variation ratio data to opening of the intake valve. The assumed fuel demand data can be used not only for controlling fuel supply but also for spark ignition timing control, air/fuel ratio control and so forth so that the engine operation control may precisely follow the actual engine driving condition for optimizing the engine performance.

Abstract: A fuel supply control system derives a basic induction volume efficiency on the basis of an intake air pressure and modifies the basic induction volume efficiency with a correction value which is derived on the basis of an engine revolution speed and the intake air pressure. An induction volume efficiency is derived on the basis of modified basic induction volume efficiency, which derived induction volume efficiency is used for deriving a basic fuel supply amount with the intake air pressure. The basic fuel supply amount thus derived is used for controlling fuel supply for the engine. Derivation of the basic induction volume efficiency is performed by an interrupt routine which may be executed in a predetermined timing derived depending upon a time or in synchronism with engine revolution cycle. The correction value may be derived in a background job.

Abstract: An electronic air-fuel ratio control apparatus in an internal combustion engine provided with an oxygen sensor emitting an output voltage in response to an oxygen concentration including the same in nitrogen oxides in an exhaust gas from the engine which controls an air-fuel ratio of an air-fuel mixture by a feedback correction-control based on a oxygen sensor having the nitrogen oxides-reducing catalytic layer, the detection of a theoretical air-fuel ratio is performed on a richer side comparing with the output on the detection of a theoretical air-fuel ratio by an oxygen sensor without the nitrogen oxides-reducing function and is not changed even though the nitrogen oxides concentration changes. Accordingly the feedback air-fuel ratio control operates to decrease the amount of nitrogen oxides and to stabilize the air-fuel ratio control.

Abstract: A fuel injection control system is directed a sequential injection type fuel injection internal combustion engine for injecting fuel to each engine cylinder at different timings. Acceleration enrichment asynchronous fuel injection is initiated in response to an acceleration demand. Acceleration enrichment is further performed for subsequent injection cycles to compensate for engine load indicative sensor signals which differ from actual engine load due to errors in an air flow meter.

Abstract: An apparatus for use with a multi-cylinder internal combustion engine including a plurality of fuel injectors, each being operable in its open position for injecting fuel into an intake port with which an intake valve is in cooperation for regulating the entry of combustion ingredients into the corresponding cylinder. The apparatus includes a control circuit for operating the fuel injectors in a predetermined sequence. The control circuit determines a length of time one fuel injector to be operated is in its open position in response to selected engine operating conditions. The control circuit opens the one fuel injector at a time to terminate the determined time length substantially at the same time when the corresponding intake valve opens. In addition, the control circuit prolongs the determined time length in response to a demand for engine acceleration produced when the one fuel injector is in its open position.

Abstract: A fuel injection control system is directed for a sequential injection type fuel injection internal combustion engine for injecting fuel for each engine cylinder at different timing. Acceleration enrichment asynchroneous fuel injection is initiated in response to an acceleration demand. Acceleration enrichment is further performed for subsequent given injection cycles for compensation of smaller engine load indicative sensor signal than actual engine load due to error in an air flow meter.

Abstract: A fuel supply control system is specifically adapted for an internal combustion engine which performs multi-point injection to supply fuel to respective engine cylinders at mutually independent timing. The combustioning condition in each cylinder is monitored to detect occurrence of fluctuation of combustioning conditions exceeding a predetermined magnitude for initiating fuel delivery amount correction, for compensating fluctuation of engine speed, which is caused by fluctuation of combustioning conditions among the individual engine cylinders.

Abstract: An electronic air-fuel ratio control apparatus in an internal combustion engine provided with an oxygen sensor emitting an output voltage in response to an oxygen concentration including the oxygen in nitrogen oxides in an exhaust gas from the engine. The apparatus controls the air-fuel ratio of an air-fuel mixture by a feedback correction-control based on a fuel injection quantity in an on-off manner. By using an oxygen sensor having a nitrogen oxides-reducing catalytic layer, the detection of a theoretical air-fuel ratio is performed on a richer side compared to the output on the detection of a theoretical air-fuel ratio by an oxygen sensor without the nitrogen oxides-reducing function, and is not changed even through the nitrogen oxides concentration changes. Accordingly, the feedback air-fuel ratio control acts to decrease the amount of nitrogen oxides so as to stabilixe the air-fuel ratio control.

Abstract: An electronic air-fuel ratio control apparatus in an internal combustion engine provided with a learning correction function correcting a basic fuel injection quantity in response to engine states and with an oxygen sensor emitting an output voltage in response to an oxygen concentration including the same in nitrogen oxides in an exhaust gas from the engine controls an air-fuel ratio by a feedback-control of an air-fuel ratio based on a fuel injection quantity in an on-off manner. By using the oxygen sensor having the nitrogen oxides-reducing catalytic layer, the detection of a theoretical air-fuel ratio is performed on a richer side comparing with the output on the detection of a theoretical air-fuel ratio by an oxygen sensor without the nitrogen oxides-reducing function and is not changed even though the nitrogen oxides concentration changes.

Abstract: A setting device of basic fuel injection amount for an internal combustion engine in an operating region of acceleration comparing a detected amount of intake airflow with a retrieved amount of intake airflow stored with the area of opening of a throttle valve and the engine velocity used as parameter, and when the detected amount is less than the retrieved amount, modifying the detected amount on the basis of the change ratio of opening area in the throttle valve, the engine load and the engine velocity, thereby modifying the detected amount so that it is close to the amount required by the engine.

Abstract: An electronically controlled fuel injection device for an internal combustion engine during engine acceleration determines a basic amount of injected fuel based on the amount of intake airflow detected by an airflow meter and the engine velocity until the portion filled into the intake air manifold is detected, and then a basic amount of injected fuel based on the data of intake airflow which has been recorded excluding the portion filled into the intake air manifold.