An engine includes an air intake system, an exhaust system, a single-cylinder-sourced EGR system, an exhaust sensor that is disposed to monitor exhaust gas from the single one of the cylinders, and a diverter valve. A controller includes an instruction set that executable to determine operation of the engine in a fuel cut-off mode, discontinue fuel flow to the single one of the cylinders, divert exhaust gas from the single one of the cylinders to the air intake system, determine an airflow, temperature, and an equivalence ratio of the diverted exhaust gas from the single one of the cylinders, determine a mass flowrate of oxygen in the diverted exhaust gas, integrate the mass flowrate of oxygen in the diverted exhaust gas, and discontinue the diverting of the exhaust gas from the single one of the cylinders when the integrated mass flowrate of oxygen is greater than a threshold value.

An internal combustion engine includes an ignition plug and an electronic control unit. The electronic control unit is configured to: (i) execute a lean-burn operation in a first operation region, (ii) execute an operation in a second operation region at an air-fuel ratio lower than an air-fuel ratio during the lean-burn operation, and (iii) control a gas flow in a cylinder so that a ratio of a change in a gas flow speed around the ignition plug during ignition to a change in an engine rotation speed in a first engine rotation speed region within the first operation region is smaller than the ratio in a second engine rotation speed region within the second operation region.

Methods and systems are provided for reducing temperature of an engine or single cylinder(s) of the engine at start/stop events where the engine is stopped from combusting air and fuel, and in response to an overheating engine condition. In one example, a method comprises activating an electric air compressor to direct cooling air flow through a first single cylinder of the engine, to reduce a temperature of the first single cylinder to a desired temperature prior to a request to restart the engine. In this way, a single cylinder indicated to be overheating may be effectively cooled, without employing methodology that would otherwise cool the engine as a whole, which may thus prevent engine degradation and which may conserve power of an onboard energy storage device.

Provided is a control device for an internal combustion engine that includes an EGR device equipped with an EGR cooler bypass passage and a flow-rate-ratio control valve equipped with a valve disc and capable of controlling a flow rate ratio. The control device is configured, when an opening degree control execution condition is met, to execute a vibration reduction control for controlling the flow-rate-ratio control valve such that the opening degree of the valve disc becomes greater than or equal to a vibration reduction opening degree that is greater than a minimum opening degree within an opening degree control range of the valve disc. The opening degree control execution condition includes a requirement that a parameter (pulsation level value) that becomes greater when exhaust pulsation acting on the valve disc is greater is equal to or greater than a first threshold value.

A method for operating an internal combustion engine for a motor vehicle including receiving measurement signals of a cylinder pressure sensor and determining cylinder pressure fluctuations as a function of the received measurement signals of the cylinder pressure sensor. The method also includes increasing an exhaust gas recirculation rate of the internal combustion engine as a function of the determined cylinder pressure fluctuations until a predefined limiting value of the cylinder pressure fluctuations is reached. In addition, the method includes determining an actual value of the exhaust gas recirculation rate if the predefined limiting value of the cylinder pressure fluctuations is reached, and storing the determined actual value as a setpoint value for the exhaust gas recirculation rate of the internal combustion engine.

An internal combustion engine has a control device, an EGR valve that adjusts an EGR rate, a PCV valve that adjusts an opening degree of a first PCV passage that communicates an inside of a crankcase and a downstream side of a throttle valve. The control device operates the throttle valve in a closing direction in response to a deceleration request. The control device adjusts an opening degree of the PCV valve based on an immediately preceding EGR rate immediately before reception of the deceleration request.

A multi-stage turbo supercharging system includes: a bypass passage which bypasses a turbocharger from among a plurality of turbochargers, in an intake passage or an exhaust passage of the engine; a bypass valve disposed in the bypass passage; an operation mode selection part; a bypass valve opening degree map selection part configured to select at least one bypass valve opening degree map in accordance with the operation mode selected by the operation mode selection part, from among a plurality of bypass valve opening degree maps which represent respective relationships between a plurality of control parameters of the engine and an opening degree of the bypass valve; a bypass valve opening degree determination part configured to determine an opening degree command value for the bypass valve on the basis of the bypass valve opening degree map and control parameter information representing the plurality of control parameters; and a bypass valve opening degree control part configured to control the opening degree of the bypass valve on the basis of the opening degree command value for the bypass valve.

The present disclosure relates to a method for removing residual purge gas in operating an active purge system and includes determining evaporation gas purge stop in a control unit, closing a PCSV mounted on a purge line connecting a canister and an intake pipe, and determining whether all of the evaporation gas flowed into the intake pipe is flowed into a combustion chamber, so that all of the evaporation gas flowed into an intake pipe during travelling can be flowed into and combusted in the combustion chamber.

An ECU includes a cooling water temperature sensor, an intake air temperature sensor, a storage unit, a determination unit, and a calibration unit. In an after-run control performed after the internal combustion engine stops, the determination unit compares a cooling water temperature Tw detected by the cooling water temperature sensor with a first threshold value T1 and determines that the environment is not the cold environment in which an EGR differential pressure sensor is likely to be frozen, if the cooling water temperature Tw is equal to or higher than the first threshold value T1, or if the cooling water temperature Tw is less than the first threshold value T1 but is equal to or higher than a second threshold value T2 which is lower than the first threshold value T1 and an intake air temperature Ta from the intake air temperature sensor is equal to or higher than a third threshold value T3, and determines that the environment is the cold environment otherwise. When the environment is determined as not to be the cold environment, the calibration unit obtains a calibration reference value based on the detection value from the EGR differential pressure sensor. The storage unit stores the calibration reference value obtained by the calibration unit.

A storage device stores mapping data and association data. The mapping data defines a mapping that outputs an estimated value of the temperature of a catalyst using a warm-up operation amount variable and the previous value of the estimated value as an input. The association data associates the integrated value of an intake air amount of an internal combustion engine from the startup of the engine and the temperature of the catalyst. The execution device repeatedly calculates the estimated value based on the output of the mapping. When the correspondence relationship between the integrated value and the estimated value is different from the correspondence relationship between the integrated value and the temperature of the catalyst in the association data, the warm-up process is determined to have an anomaly.