An engine control device for an engine provided with a supercharger, including a cylinder injection valve and a port injection valve. The device includes an injection controller that controls injections of fuel through the cylinder injection valve and through the port injection valve, on the basis of at least a load on an engine. The injection controller, in a low load operating state, causes the fuel to be injected through the port injection valve; in an intermediate load operating state, causes the fuel to be injected through the cylinder injection valve during an intake stroke, and causes the fuel to be injected through the port injection valve; and in a high load operating state, causes the fuel to be injected through the cylinder injection valve at least during an intake stroke and during a compression stroke.

Methods and systems are provided for restarting an engine when a high pressure fuel pump is degraded. In response to an indication of high pressure fuel pump degradation, fuel may be injected during an intake stroke, rather than a compression stroke, for a selected number of combustion events since the engine restart. By shifting to an intake stroke injection, the engine may be started even when sufficient fuel rail pressures are not available.

A method for detecting a fault during operation of an internal combustion engine having manifold injection and direct injection; the internal combustion engine being controlled in two different combustion cycles, in each instance, for introducing a fuel quantity and a corresponding air quantity into a combustion chamber of the internal combustion engine, with different distributions of the fuel quantity to the manifold injection and the direct injection in the two combustion cycles; for each of the two combustion cycles, a value of a ratio of the air quantity introduced into the combustion chamber to the fuel quantity introduced into the combustion chamber being ascertained; and if at least one of the two values differs from a corresponding comparison value by more than a first threshold value, a type of fault during operation of the internal combustion engine being deduced in light of the difference.

A control apparatus of an internal combustion engine having an injector which directly injects fuel into a combustion chamber of a cylinder and a spark plug which ignites an air-fuel mixture containing the fuel injected by the injector includes an air-fuel ratio acquisition unit acquiring an air-fuel ratio of the air-fuel mixture in the combustion chamber, a nitrogen oxide concentration acquisition unit acquiring a concentration of nitrogen oxide in a combustion gas exhausted from the internal combustion engine, and a stratification level estimation unit estimating a level of stratification as a measure of level of distribution of the air-fuel mixture at a predetermined air-fuel ratio or below in a vicinity of the spark plug. The stratification level estimation unit estimates the level of stratification according to the air-fuel ratio acquired by the air-fuel ratio acquisition unit and the concentration of nitrogen oxide acquired by the nitrogen oxide concentration acquisition unit.

A direct injection injector injects all of fuel having an idle required fuel amount required for an idle operation and makes a port injection injector inject no fuel from a second time to a third time so that an internal combustion engine executes idle operation from second time to third time. A fuel cut operation in which the fuel is not injected from both the direct injection injector and the port injection injector is executed from third time so that operation of the internal combustion engine is stopped at or after third time. At least one of the direct injection injector and the port injection injector inject the fuel so that operation of the internal combustion engine is restarted when a predetermined engine restart condition is satisfied under a state where operation of the internal combustion engine is stopped at or after third time.

A lift amount variable mechanism is configured to switch a cam for driving an intake valve (drive cam) between two types of intake cams in lift amount (i.e. a large lift cam and a small lift cam). In a first embodiment of this disclosure, the lift amount variable mechanism is controlled by an ECU so that the small lift cam is selected as the drive cam for control that promotes activation of an exhaust gas cleaning catalyst (catalyst warm-up control).

Internal combustion engine has direct injection fuel injection valve and port injection fuel injection valve. A requested fuel injection amount is calculated according to an engine operation condition. When the requested fuel injection amount is in first operation region in which the minimum fuel injection amount of direct injection fuel injection valve is exceeded, a direct injection fuel injection valve fuel injection amount is adjusted based on the requested fuel injection amount and a fixed amount, while maintaining a port injection fuel injection valve fuel injection amount at the fixed amount. First operation region is at least a region in which the requested fuel injection amount exceeds the direct injection fuel injection valve minimum fuel injection amount. In first operation region, the port injection fuel injection valve fuel injection amount is fixed at the minimum fuel injection amount of port injection fuel injection valve.

A method for engine drivability robustness includes: dividing, by an engine controller, an engine state into a starting condition, a stop condition, and a deceleration condition; dividing an injection mode index of a fuel injection into a suction compression injection of the starting condition, a suction split injection of the stop condition, and a suction compression split injection of the deceleration condition, respectively, depending on a low volatile fuel condition; and performing a variable indexing mode to prevent an engine off by applying a lambda control factor for a rich lambda control by an increase in fuel amount to the deceleration condition.

An internal combustion engine is provided with an EGR device and is configured to be capable of executing an operation based on a first air-fuel ratio and an operation based on a second air-fuel ratio leaner than the first air-fuel ratio. In a case where an ECU decreases the amount of air flowing into a combustion chamber and decreases an EGR rate in response to a predetermined torque reduction request for the internal combustion engine, the ECU performs the operation based on the first air-fuel ratio in a case where an immediately preceding EGR rate immediately before the torque reduction request is made is lower than a first threshold and performs a stratified combustion operation based on the second air-fuel ratio in a case where the immediately preceding EGR rate is equal to or higher than the first threshold.

In an internal combustion engine an air-fuel ratio is switched between at least two target values without generating torque fluctuations, while a deterioration in fuel consumption performance and exhaust performance is suppressed. When a condition for switching a combustion mode from stoichiometric combustion to lean combustion and a condition that the amount of change in a target torque is less than or equal to a predetermined value are satisfied, a target EGR rate is increased towards an EGR limit prior to switching the target air-fuel ratio. The target air-fuel ratio is maintained at the stoichiometric air-fuel ratio until the target EGR rate reaches the EGR limit, and in response to the target EGR rate reaching the EGR limit, the target air-fuel ratio is changed towards a lean air-fuel ratio.