A method using compensation learning strategy for a diagnostic of an internal combustion engine component includes operating the component via an actuator command to establish a first operating parameter representative of a first mode of component operation. The method also includes identifying a drift in the first parameter negatively affecting the first mode of operation. The method additionally includes determining compensation to the actuator command to counteract the first parameter drift during the first mode of operation. The method also includes determining compensation to the first parameter using the determined actuator command compensation. The method additionally includes applying the determined parameter compensation directly to the first parameter. The method also includes operating the component using the actuator command to establish a second operating parameter representative of a second mode of component operation. Furthermore, the method includes identifying a drift in the second parameter negatively affecting the second mode of operation.

A method using compensation learning strategy for a diagnostic of an internal combustion engine component includes operating the component via an actuator command to establish a first operating parameter representative of a first mode of component operation. The method also includes identifying a drift in the first parameter negatively affecting the first mode of operation. The method additionally includes determining compensation to the actuator command to counteract the first parameter drift during the first mode of operation. The method also includes determining compensation to the first parameter using the determined actuator command compensation. The method additionally includes applying the determined parameter compensation directly to the first parameter. The method also includes operating the component using the actuator command to establish a second operating parameter representative of a second mode of component operation. Furthermore, the method includes identifying a drift in the second parameter negatively affecting the second mode of operation.

A blowback air amount is an amount of air that is part of the air that has flowed into a combustion chamber and is blown back into an intake passage before an intake valve closes. If the blowback air amount increases, a controller causes a fuel injection valve to inject fuel by an amount increased with respect to a fuel amount for a case in which the blowback air amount remains constant. The controller sets an increase amount of fuel injected from the fuel injection valve to a greater value when the stoichiometric air-fuel ratio of the fuel injected from the fuel injection valve is small than when the stoichiometric air-fuel ratio of the fuel injected from the fuel injection valve is great.

There is provided: a NOx occlusion reduction-type catalyst that is provided in an exhaust passage of an internal combustion engine, occludes NOx in exhaust when the exhaust is in a lean state, and reduces and purifies the occluded NOx when the exhaust is in a rich state; an exhaust injector that is provided in the exhaust passage and is positioned further upstream than the NOx occlusion reduction-type catalyst; a NOx-purging control unit that performs NOx purging of reducing and purifying the NOx occluded in the NOx occlusion reduction-type catalyst by lowering the exhaust to a prescribed target lambda by fuel injection by the exhaust injector; and a NOx-purging-prohibition processing unit that inhibits performance of the NOx purging in a case where the exhaust cannot be lowered to the target lambda even if the fuel injection is performed at a maximum limit injection amount of the exhaust injector.

Disclosed is a procedure to minimize NOx during varying engine loads in a 4-stroke diesel engine including at least one cylinder with a cylinder head, first piston on a connecting rod, one actuator mounted on the cylinder head and one of the actuator operated second piston lockable via a hydraulic circuit in various positions in a combustion chamber. The second piston, at the latest during the current compression stroke is actuated by the actuator and locked in the combustion chamber, where it by the first piston introduced air is compressed in a predetermined compression ratio to meet an existing engine load wherein the free operated inlet valve is brought to close the inlet stroke at a piston position where the volume of the combustion air as introduced at the end of the compression stroke gives the predetermined compression ratio and that the injector injects the stated amount of fuel.

A method is provided for controlling an engine exhaust with an upstream sensor and a downstream sensor. The method comprises adjusting a set-point for the downstream sensor based on a rate of change of air mass flow upstream of the engine and adjusting fuel injection to control exhaust fuel-air ratio (FAR) at the downstream sensor to the adjusted set-point, and to control exhaust FAR at the upstream sensor to an upstream sensor set-point.

A first intake air amount an engine is calculated based on a detected value of an intake air flow rate of an air flowmeter. A second intake air amount is calculated based on any one of a detected value of an intake pipe pressure and a throttle opening degree instead of the detected value of the intake air flow rate. When it is determined that the intake pulsation is not large, a difference amount of the second intake air amount from the first intake air amount is calculated. A corrected second intake air amount, which is a sum of the second intake air amount and the difference amount, is set as an intake air amount calculated value when it is determined that the intake pulsation is large.

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 diagnosing leakage of a fuel vapor dual purge system is provided. The method includes determining whether an operation region of a vehicle is an operation region in which a turbocharger is operated and adjusting a flow amount of intake air flowing into the turbocharger according to an operation region in which the turbocharger is operated. A hydrocarbon collecting amount of a canister connecting fuel vapor generated in the fuel tank is calculated and a flow amount of the fuel vapor passing first and second purge lines is adjusted. A leak of the fuel vapor is diagnosed in the first purge line and the second purge line.

A method for controlling fuel injection to an engine may include calculating an amount of air passing through a throttle, which is actually controlled, from a calculated amount of air in an intake manifold, which is calculated from a pressure value detected by a pressure sensor installed in the intake manifold connecting the throttle and a cylinder to each other, and a calculated pressure change in the intake manifold. The method may further include predicting an actual amount of air to be sucked into the cylinder when mixed with fuel from the calculated amount of air in the intake manifold and the calculated amount of air passing through the throttle. The method may also include injecting an amount of fuel according to the predicted actual amount of air to be sucked into the cylinder.