Operating an internal combustion engine (110) having at least two combustion chambers (1-6) and at least one exhaust-gas catalytic converter (130). In one example, a beginning of the load operation phase of the internal combustion engine (110) that adjoins a coasting phase is detected. A combustion chamber of the at least two combustion chambers (1-6) is determined as the first combustion chamber; and one of other the combustion chambers is selected as the purging combustion chamber. An exhaust gas of the purging combustion chamber is directed into the same exhaust-gas catalytic converter (130) as an exhaust gas of the first combustion chamber. A first fuel quantity is fed into the purging combustion chamber such that the first fuel quantity, prior to igniting the fuel in the purging combustion chamber, is discharged to be partially or fully non-combusted in the direction of the exhaust-gas catalytic convertor (130).

Methods and systems for operating an engine that includes adjustable poppet valve timing and an exhaust gas recirculation valve are described. In one example, the exhaust gas recirculation valve is opened and the timing of the poppet valves is retarded so that an amount of fresh air that is pumped by the engine to an after treatment device may be reduced.

A control apparatus for an internal combustion engine includes circuitry configured to control a fuel injector of the internal combustion engine to stop injecting fuel to reduce torque generated by the internal combustion engine during upshift. The circuitry is to acquire a target injection amount parameter corresponding to a target injection amount of the fuel to be injected by the fuel injector to operate the internal combustion engine based on an operation state parameter corresponding to an operation state of the internal combustion engine. The circuitry is to acquire a minimum injectable amount parameter corresponding to a minimum injectable amount of the fuel injectable from the fuel injector. The circuitry is to control the fuel injector to start injecting the fuel when the minimum injectable amount parameter exceeds the target injection amount parameter while the fuel injector is controlled to stop injecting the fuel during the upshift.

A CPU of a control device is configured to perform a specific cylinder fuel cutoff process of causing an internal combustion engine to operate such that supply of fuel to some cylinders out of a plurality of cylinders is stopped and supply of fuel to the other cylinders is maintained and a fastening force decreasing process of decreasing a fastening force of a lockup clutch of a torque converter. The CPU is configured to start the specific cylinder fuel cutoff process in a state in which the fastening force has been decreased through the fastening force decreasing process when the specific cylinder fuel cutoff process is performed in a state in which the internal combustion engine operates with a load.

A control device and a control method for a multi-cylinder internal combustion engine including a post-processing device are provided. The control device includes an electronic control unit executing a temperature raising process of raising the temperature of the post-processing device and a recovery-time process. The temperature raising process includes a stopping process and a rich process. In the stopping process, supply of fuel to several of cylinders is stopped. In the rich process, the air-fuel ratio of an air-fuel mixture for different ones of the cylinders other than the several cylinders is made lower than the stoichiometric air-fuel ratio. In the recovery-time process, the concentration of unburned fuel in exhaust gas discharged to the exhaust passage is made higher than an equivalent concentration, when the temperature raising process is stopped. The equivalent concentration is the concentration of unburned fuel being just enough to react with oxygen in the exhaust gas.

A system according to the principles of the present disclosure includes a storage capability module and at least one of an engine speed control module and a spark control module. The storage capability module determines a capability of a catalytic converter to store oxygen. The engine speed control module controls a speed of an engine based on the oxygen storage capability of the catalytic converter. The spark control module controls a spark timing of the engine based on the oxygen storage capability of the catalytic converter.

A control apparatus of an internal combustion engine is provided. The internal combustion engine includes a port injection valve that injects fuel into an intake-air port, and a cylinder injection valve that injects fuel into a cylinder. The control apparatus includes an electronic control unit that controls the port injection valve and the cylinder injection valve such that when returning from a fuel cut, a value of a port increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a port injection, differs from a value of a cylinder increase amount correction, which is a fuel increase amount correction in which a fuel amount is decreased with a lapse of time during a cylinder injection.

Methods and systems are provided for protecting an exhaust catalyst from degradation during a DFSO event. Exit from DFSO due to pedal input received from an operator with a jittery foot is averted by filtering the pedal input differently when operating in a DFSO mode as compared to when operating out of the DFSO mode. Exit from DFSO is confirmed after receiving a higher than threshold pedal position input for a sustained period of time, or when an integrated fuel injection amount exceeds a threshold amount.

Methods and systems are provided for a fuel system. In one example, a method includes comparing a resistance of a solenoid coil of a direct injector to a threshold resistance. The method further includes selecting one of a transient or a steady-state pressure-based injector balancing (PBIB) model in response to the comparison.

An engine device includes: an engine; and a control device that executes a return rich control that controls the engine so that an air-fuel ratio becomes rich over a predetermined period after the engine returns from the fuel cut. When the engine is intermittently stopped during the execution of the return rich control, the return rich control is executed for a period shorter than the predetermined period after the engine is restarted. Thus, when the engine is intermittently stopped during the execution of the return rich control and the engine is restarted thereafter, it is possible to suppress a total period of the return rich control from becoming long. As a result, it is possible to suppress an increase in the amount of hydrocarbons in the exhaust gas and suppress deterioration of emissions.