A method is provided for avoiding incorrect combustion misfire fault detection in an internal combustion engine in a motor vehicle with a dual mass flywheel. In order to detect combustion misfiring, a characteristic variable, which is dependent on the acceleration of the internal combustion engine, is determined continuously during the ongoing operation of the internal combustion engine and compared with a predefined irregular running threshold value. When the irregular running threshold value is exceeded, a combustion misfire is detected, wherein the frequency of detected combustion misfiring, for example at a specific number of crank shaft revolutions, is detected. When a defined frequency threshold is exceeded, a combustion misfire fault detection is activated. When a dual mass flywheel bounce is detected with the simultaneous detection of combustion misfiring, the injection of at least one cylinder is reduced or switched off for a predefined frequency or for a predefined time.

Methods and systems are provided for a hydrogen combustion engine. In one example, a method may include operating the hydrogen combustion engine at one of two combustion air ratios, wherein a combustion air ratio between the two is avoided via adjusting one or more operating parameters.

An internal combustion engine includes a port injector that injects fuel into an intake port and a direct injection injector that injects fuel directly into a combustion chamber. When the internal combustion engine is in a low load condition while requiring fuel injection, a controller stops fuel injection through the port injector so that an entire required fuel injection amount is injected through the direct injection injector. As a result of this processing, the fuel pressure of the direct injection injector is reduced quickly in the low load condition.

Methods and systems are provided for monitoring and adapting sensors and actuators in the induction system and exhaust system of an internal combustion engine during a period of time in which fresh air is flowing through the internal combustion engine without fuel delivery. According to the disclosure, the period of time in which fresh air is flowing through the internal combustion engine when fuel delivery is turned off and the monitoring and adapting is being carried out is extended by transferring torque produced by electric motor to the internal combustion engine.

A variable valve operating system assembled in an engine includes a first rocker arm contacting with a valve, a second rocker arm no contacting with any valve, a lost motion spring bringing the second rocker arm into contact with a cam, and switching device for switching the first/second rocker arms to a coupled or uncoupled state. An operation control apparatus for the engine includes element for determining whether or not an engine speed is higher than a first speed at which supply of fuel is allowed to be temporarily stopped, and element for setting a requested quantity of increase/decrease in internal resistance of the engine. When the engine speed is higher than the first speed and an accelerator opening degree is 0%, the switching device switches the first/second rocker arms to the coupled or uncoupled state based on the requested quantity.

Methods and systems are presented for assessing the presence or absence of engine torque deviation which may indicate air-fuel ratio imbalance between engine cylinders. In one example, the method may include assessing the presence or absence of engine torque variation based on engine torque deviation from a desired engine torque during a deceleration fuel shut-off event.

A PCM (50) that is an engine control device functions to acquire a master vac negative pressure which is the negative pressure of a stabilized chamber of a master vac (126) which amplifies a brake pedal depressing force applied to a brake pedal (102), and also acquire a brake working fluid pressure that is a braking hydraulic pressure produced by a master cylinder (144) in accordance with the brake pedal depressing force amplified by the master vac (126), and in a case where both accelerator pedal (104) and a brake pedal (102) are depressed or actuated simultaneously, determine whether or not it is necessary to decrease engine output based on such master vac negative pressure and brake working fluid pressure to execute the output decreasing control for decreasing the engine output.

Provided is an engine working apparatus capable of smoothly decelerating an engine. The engine working apparatus includes: an internal combustion engine including a piston reciprocally movable in a cylinder and a combustion chamber defined by the piston; an ignition plug configured to ignite air-fuel mixture in the combustion chamber; a detector configured to detect a rotation number of the internal combustion engine; and a controller configured to control an ignition timing of the ignition plug based on the detected rotation number, execute feedback control of determining the ignition timing based on a deviation between a target rotation number and the detected rotation number, and to execute the feedback control when the detected rotation number satisfies a predetermined deceleration condition.

An apparatus for controlling a low-pressure exhaust gas recirculation (LP-EGR) system for freezing prevention includes an intake air temperature sensor configured to measure a temperature of intake air introduced from outside, at least one engine driving sensor used to diagnose and learn a driving state of an engine, the LP-EGR system configured such that at least a portion of exhaust gas flows into the LP-EGR system as intake air, and a controller configured to perform diagnosis and learning of the driving state of the engine using the at least one engine driving sensor or to operate the LP-EGR system depending on the temperature of the intake air measured by the intake air temperature sensor when coasting conditions of a vehicle are satisfied.

Disclosed are a vehicle and an engine control method for more conveniently restarting an engine in the state in which a function of automatically turning off the engine is activated during braking for improving fuel efficiency. The engine control method includes turning off an engine through an idle stop and go (ISG) system during braking due to manipulation of a brake pedal, determining whether at least one preset starting condition is satisfied based on information on a forward environment, and turning on the engine irrespective of whether manipulation of the brake pedal is released when any one of the at least one starting condition is satisfied.