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.

Methods and systems are provided for adjusting a location of a fuel injection in response to a substitution rate and a desired EGR flow. In one example, a method may include injecting a first fuel to a combustion chamber via a direct injector positioned to inject directly into the combustion chamber, injecting a second, different, fuel to the combustion chamber via an exhaust port injector positioned to inject toward an exhaust valve of the combustion chamber, and combusting the first and second fuels together in the combustion chamber.

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.

Additional approaches for the reduction of particulate emissions in gasoline engines using optimized port+direct injection are described. These embodiments include control of the amount of directly injected fuel so as to avoid a threshold increase in particulates due to piston wetting and reduction of cold start emissions by use of air preheating using variable valve timing.

An HT cooling system cools at least a cylinder block with HT cooling water. An LT cooling system cools an intake port with LT cooling water that is at a lower temperature than the HT cooling water. A controller performs an ignition retard control that involves correcting the ignition timing based on the result of detection of a knock by a knock sensor, and a cooling enhancement control that involves enhancing cooling by the LT cooling system in the case where a knock is detected compared with the case where no knock is detected. The way of cooling by the HT cooling system is unchanged whether a knock is detected.

A control device is capable of executing: an ignition time calculation process of calculating a target ignition time of an ignition plug; a stop process of stopping combustion control for some cylinders of a plurality of cylinders; and a compensation process of controlling a motor generator during the stop process, such that the motor generator compensates a drive power that is lost due to the stop of the combustion control. The control device prohibits the execution of the stop process when the target ignition time calculated in the ignition time calculation process is on a retard side of a predetermined prescribed time.

To provide a controller and a control method, for an internal combustion engine, that can detect occurrence of knocking appropriately, even though the frequency distribution of the knock signal is distorted according to the occurrence state of knocking. The controller for the internal combustion engine calculates the background level by processing a low pass filter to the knock signal; and performs a low side frequency increase which makes a low side frequency, which is a cutoff frequency of the low pass filter in the case where the knock signal is smaller than an output value of the low pass filter, higher than a high side frequency, which is a cutoff frequency of the low pass filter in the case where the knock signal is larger than the output value of the low pass filter.

A method for checking the association of structure-borne noise sensors of an internal combustion engine having a plurality of cylinders, which internal combustion engine can be operated in diesel operation or with individualized gas injection and in the case of which internal combustion engine a structure-borne noise sensor is arranged in the region of each cylinder, wherein the output signals of the structure-borne noise sensors reflect a knock index and are captured by a computing unit, wherein the internal combustion engine is operated in order to perform the method. The output signals of all structure-borne noise sensors are determined during at least one working cycle, which is formed by two revolutions of a crankshaft, in the respective positions of the crankshaft. The output signal of a cylinder is compared with the average value or the median value of the output signals of other cylinders.