Systems, apparatuses, and methods of controlling an ignitor are disclosed. A method includes: receiving, by a controller, fuel quality data regarding a fuel for a spark-ignition engine; determining, by the controller, a fuel quality metric based on the fuel quality data; and controlling, by the controller, an ignition energy characteristic of an ignitor in response to the fuel quality metric.

Systems and methods are provided for varying a compression ratio in an engine having a pressure reactive piston. The pressure reactive piston may include a piston crown, and a spring positioned within the piston crown, wherein the spring includes a first ring, a second ring comprising a plurality of apertures, a rolling element positioned within each of the plurality of apertures, and a third ring. The first ring, the second ring, and the third ring of the spring may be arranged concentrically and the second ring may be positioned between the first ring and the third ring.

An engine-equipped vehicle capable of preventing gear noise and gear wear when the engine is started is provided. A multicylinder engine, a gear transmission that shifts power from the multicylinder engine by a shift operation, a centrifugal clutch arranged in a power transmission path from the multicylinder engine to the gear transmission, and an electronic control device that controls an operation of the multicylinder engine are included and the engine is configured to be started with a partial cylinder operation start where under control of the electronic control device, only some cylinders are operated and an operation of other cylinders is stopped.

A method of controlling an ignitor for a spark-ignition engine includes receiving, by a controller, at least one of fuel quality data regarding a fuel for the spark-ignition engine or a characteristic regarding the ignitor for the spark-ignition engine. The method additionally includes controlling, by the controller, an ignition energy characteristic of the ignitor in response to the at least one of the fuel quality data regarding the fuel or the characteristic regarding the ignitor for the spark-ignition engine.

A control device for a vehicle including an internal combustion engine and an electric rotary machine connected to the internal combustion engine in a power-transmittable manner is able to perform torque-down through ignition delay control for delaying an ignition timing of the internal combustion engine and regeneration control for performing regeneration using the electric rotary machine when there is a torque-down request based on a vehicle state. The control device is configured to perform torque-down corresponding to a deficiency by delaying the ignition timing of the internal combustion engine when an actual torque of the electric rotary machine through the regeneration control is deficient for the torque-down request.

A method of controlling an ignitor for a spark-ignition engine includes receiving, by a controller, at least one of fuel quality data regarding a fuel for the spark-ignition engine or a characteristic regarding the ignitor for the spark-ignition engine. The method additionally includes controlling, by the controller, an ignition energy characteristic of the ignitor in response to the at least one of the fuel quality data regarding the fuel or the characteristic regarding the ignitor for the spark-ignition engine.

Systems, apparatuses, and methods of controlling an ignitor are disclosed. A method includes: receiving, by a controller, fuel quality data regarding a fuel for a spark-ignition engine; determining, by the controller, a fuel quality metric based on the fuel quality data; and controlling, by the controller, an ignition energy characteristic of an ignitor in response to the fuel quality metric.

Systems and methods for unsticking intake and exhaust valves of an engine are described. In one example, valves that may be adjustably timed relative to an engine crankshaft position may be adjusted to unstick intake and/or exhaust valve that are stuck open or closed. In addition, fuel injection timing and spark timing may be adjusted in an effort to unstick intake and/or exhaust valves.

A method for extracting characterizing features from an ion current trace retrieved from spark plugs of cylinders of an internal combustion engine, comprises the steps of: i. dividing the ion current signal into crank angle subintervals; 5 ii. calculating a measure of ion current in each crank angle subinterval; and iii. Performing a calculation on the measure of ion currents from different subintervals such that the result of the calculation is dimension free. Further it relates to a method of monitoring combustion processes where a plurality of ion current signals from a number of spark plugs (4A, 4B) are 10 retrieved and used in combination.

A method for controlling the ignition energy of a sparkplug electrode of an ignition system comprises: providing a base current (I.sub.base) and a base duration (D.sub.base) which corresponds to the current and duration, respectively, of a physical model at a fixed engine operating point; multiplying the base current (I.sub.base) and the base duration (D.sub.base) with a sparkplug state indicator (SSI) based correction factor and with an engine operating state (EOS) based factor for achieving a final global current (I.sub.glo) and a final global duration (D.sub.glo), respectively; and communicating the final global current (I.sub.glo) and the final global duration (D.sub.glo) to a control unit for controlling the ignition energy and ignition duration of the sparkplug electrode. Further executing real-time energy control based on misfire flag status and, in the end, making sure that the optimum energy is into application by realizing optimum energy tests.