A method of operating an dedicated exhaust gas recirculation engine including a water gas shift catalyst by supplying ambient air and fuel to a dedicated cylinder at a first fuel to air equivalence ratio in the range of greater than 1.0 to 1.6 for a first number of engine cycles and, for a second number of engine cycles, supplying ambient air and fuel to the dedicated cylinder at a second fuel to air equivalence ratio in the range of 0.7 to less than 1.0. During the second number of cycles, spark timing of the dedicated cylinder is adjusted and a time delay when exhaust recirculated from the dedicated cylinder will be inducted into the cylinders is determined. At the end of the time delay, a second spark timing of the main cylinder is adjusted and the amount of fuel supplied to the main cylinders is increased.

A combustion control system and method for a turbulent jet ignition engine is presented. A controller is configured to access a trained feedforward artificial neural network (ANN) configured to model a first spark from a first ignition source and maximum brake torque (MBT) based on measured operating parameters, generate the first spark and MBT using the ANN, generate a second spark from a second ignition device, and determine a target spark timing. The ANN can be further configured to receive an input related to spark stagger.

A system includes an internal combustion engine having a number of cylinders, with at least one of the cylinder(s) being a primary EGR cylinder that is dedicated to provided EGR flow during at least some operating conditions. A controller is structured to control combustion conditions in the cylinders in response to one or more operating conditions associated with the engine.

A fuel injection strategy and ignition timing for a spark-ignition direct fuel injection engine are selected in response to monitored engine load in relation to a plurality of load regions. This includes selecting a preferred ignition timing based upon the engine load, and selecting a first fuel injection event that is executed post-ignition, wherein the first fuel injection event delivers a set fuel mass at a preset timing relative to the preferred timing for the spark ignition event regardless of the engine load. A first pre-ignition fuel injection event is selected, and includes a second fuel mass being injected at a second fuel injection timing, wherein an end-of-injection timing of the first pre-ignition fuel injection event is at a preset timing relative to the preferred ignition timing regardless of the engine load, and wherein the second fuel mass is determined in relation to the engine load.

Methods and systems are provided for reducing a spark plug soot load and a combustion chamber soot load by controlling spark plug timing while injecting water or washer fluid. In one example, water or washer fluid is injected during a torque reduction while advancing spark timing so as to provide at least a portion of the torque reduction while opportunistically cleaning soot from the spark plug and combustion chamber. By reducing spark plug soot load, misfire occurrence is reduced, while pre-ignition occurrence is reduced by decarbonizing the combustion chamber.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, estimates of engine fuel consumption for operating the engine with a plurality of cylinder modes or patterns while a transmission is engaged in different gears are determined and are used as a basis for deactivating engine cylinders.

Systems and methods for controlling knock in an internal combustion engine are presented. In one example, spark timing is retarded in engine cylinders where engine knock is indicated and spark is subsequently advanced after it has been retarded. The rate spark timing is advanced may be based on a way engine cylinders have been deactivated.

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

This disclosure is intended to suppress a noble metal supported by a three-way catalyst from being deteriorated by oxidation with the execution of fuel cut processing in a suitable manner. A control apparatus for a naturally aspirated gasoline engine is provided with a three-way catalyst, a first throttle valve, a second throttle valve arranged in the intake passage at the downstream side of the first throttle valve, an EGR valve, and a controller. When the controller carries out fuel cut processing and the temperature of the three-way catalyst is equal to or higher than a predetermined temperature, the controller introduces the EGR gas into a cylinder of the gasoline engine as intake air by fully closing the first throttle valve and by opening the EGR valve, and further controls an amount of the EGR gas by adjusting the degree of opening of the second throttle valve.

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.