A fuel injection control apparatus including a microprocessor. The microprocessor is configured to perform calculating a target injection time, determining a first crank angle defining a start of fuel injection and a second crank angle defining an end of fuel injection, controlling a fuel injector in an injection start priority mode in which the fuel is injected for the first target injection time from a first time point corresponding to the first crank angle or an injection end priority mode in which the fuel is injected for the second target injection time from a second time point corresponding to a target crank angle, and the controlling including controlling the fuel injector so as to inject the fuel in the injection start priority mode or the injection end priority mode in accordance with an injection mode.

A controller for an internal combustion engine is configured to execute: a process of switching the injection mode according to an engine operational state; an anomaly determination process of determining whether there is an anomaly in the injection system that is implementing a single injection mode during implementation of the single injection mode; a provisional determination process of provisionally determining whether there may be an anomaly in the injection system that is implementing the single injection mode during the implementation of the single injection mode; and an idle determination process of, if it is determined that there is an anomaly in the provisional determination process, prohibiting the automatic stop and executing, during an idle operation, the anomaly determination process by implementing an injection mode that uses only the injection system provisionally determined to have an anomaly in the provisional determination process.

A method for controlling the air-fuel ratio of a vehicle includes: calculating the air amount charged in a cylinder of an engine by using a fresh air amount, a residual air amount remaining inside the cylinder of the engine, and a backflow gas amount flowing back into the cylinder upon the valve overlap of an intake vale and an exhaust valve of the engine, correcting it with the purge gas flow rate supplied to an intake manifold of the engine when the active purge system is operated, calculating the final fuel amount by correcting the fuel amount injected by a fuel injection device with the amount of the fuel component contained in the purge gas when the active purge system is operated, and controlling the air-fuel ratio based on the final air amount and the final fuel amount.

A port injection valve injects fuel to an intake passage. In multiple injection processing, a demanded injection quantity of the fuel is divided into a synchronous injection quantity and a non-synchronous injection quantity in accordance with at least one of: the load, which is a physical quantity having a correlation with the amount of air to be filled; and the temperature of an internal-combustion engine. The fuel is injected through intake non-synchronous injection and intake synchronous injection in this order. In the intake synchronous injection, the fuel is injected synchronously with a valve-open period of an intake valve. In the intake non-synchronous injection, the fuel is injected at a timing more advanced than in the intake synchronous injection.

In an intake air flow rate calculation process, a pulsation correction coefficient calculation process is executed to calculate a pulsation correction coefficient, which is used to compensate for an output error of the air flow meter resulting from an intake air pulsation, based on an engine rotation speed, a throttle opening degree, and an atmospheric pressure, and the intake air flow rate is calculated by correcting the intake air flow rate with the pulsation correction coefficient.

A cold air intake system is provided for actively controlling airflow based upon user input and/or demand conditions. Two air inlets are provided into a sealed air box with the secondary air intake including an air control valve for modulating intrusion of intake air. The valve has a valve seat formed the housing sidewall and a flap door valve member actively actuated via a controller. The mass air flow sensor indicates total demand. A pressure sensor and a temperature sensor provide additional input from the airbox. The controller modifies the valve position based upon pressure, temperature and mass air flow. Control is biased to increase secondary air intake when airbox pressure decreases and biased to decrease secondary air intake when airbox temperature increases. Controller biasing occurs between 30° F. to 160° F. and over pressure ranges between 0.01″ H.sub.2O to 5″ H.sub.2O.

An engine controller, an engine control method, and a memory medium are provided. A second calculation process calculates an intake air amount without using a detected value of the intake air flow rate. A guard process sets a difference amount learning value as a learning reflected value when the difference amount learning value is less than or equal to an upper limit guard value and greater than or equal to a lower limit guard value. A calculation method switching process sets a sum of a second intake air amount and the learning reflected value as a calculated value of the intake air amount when it is determined that an intake air pulsation is great.

Provided are an internal combustion engine control device and control method in which a multi-injection process comprises performing an intake synchronized injection and an intake asynchronous injection to inject a required injection amount of fuel by operating a port injection valve for injecting fuel into an intake passageway. A variable process includes variably setting an injection timing for the intake synchronized injection on the basis of at least two of three parameters. The injection timing for the intake synchronized injection is expressed by the rotation angle of a crank shaft of an internal combustion engine. The three parameters include a rotational speed of the crank shaft of the internal combustion engine, a valve-opening start timing of an intake valve, and a temperature of an intake system of the internal combustion engine.

A method for controlling an engine of a vehicle includes: monitoring, by a controller, engine operation data including a crank position and an engine rotation speed; obtaining, by the controller, a measured air amount flowing into to a specific cylinder; calculating, by the controller, an expected air amount at an intake valve closing time based on the measured air amount; calculating, by the controller, a fuel amount based on the expected air amount; calculating, by the controller, an ignition timing based on the engine rotation speed and the expected air amount; and injecting, by the controller, the calculated fuel amount and performing ignition at the ignition timing.

Methods and systems are provided for operating a cylinder of an engine including a pre-chamber ignition system. In one example, a method may include determining amounts of pre-chamber gases in the cylinder prior to combustion, and adjusting an amount of fuel injected into the cylinder based on the amounts of pre-chamber gases in the cylinder. In this way, cylinder fueling may be compensated for additional air and/or fuel from the pre-chamber gases, which may increase an accuracy of the cylinder fueling and increase cylinder efficiency.