A method for operating an internal combustion engine, in particular a gas engine, preferably a lean gas engine, which has at least one cylinder, in order to improve the combustion process, a prechamber is provided for igniting a mixture in a main chamber. A pressure curve is detected by a pressure sensor in the main chamber dependent on a crank angle, and the quantity of supplied fuel is controlled or regulated for each individual cylinder using a fuel metering device and the pressure sensor dependent on a desired output and/or a desired torque and/or a desired rotational speed of the internal combustion engine.

A wheelie suppressing device comprises a wheelie determiner section which detects a wheelie state; and a wheelie suppressing section which performs a wheelie suppressing control for suppressing an engine output when the wheelie determiner section has detected the wheelie state, wherein the wheelie suppressing control includes a first suppressing control for suppressing the engine output while performing fuel feeding and an ignition operation, and a second suppressing control for suppressing the engine output by performing the fuel feeding or the ignition operation at a reduced rate.

An internal combustion engine includes a number of cylinders and a controller operably connected to interpret operating parameters related to the operation of the number of cylinders. A cylinder torque adjustment for each cylinder is determined from the operating parameters to provide a torque balancing response that reduces noise, vibration and/or harshness in engine operation.

An ECU outputs an ignition signal and a discharge waveform control signal. An ignition device performs a closing operation of an ignition switching device while the ignition signal is input into the ignition device. The ignition device adjusts a current flowing through a primary coil to a discharge current command value determined based on the discharge waveform control signal, by performing an opening-closing operation of a control switching device in a period in which the discharge waveform control signal is input into the ignition device after an input of the ignition signal into the ignition device is stopped. The ECU sets the discharge current command value that is a command value for a discharge current of a spark plug to a higher value as a rotation speed is higher, and prolongs a duration, in which discharge controller controls the discharge current, as the rotation speed is lower.

A control apparatus for an internal combustion engine is configured to: calculate measured data of MFB based on in-cylinder pressure detected by an in-cylinder pressure sensor; execute engine control based on a measured value of a specified fraction combustion point that is calculated based on the measured data of MFB; and calculate a first correlation index value for the measured data (current data) and the reference data of MFB and a second correlation index value for the current data and the immediately preceding past data. The engine control is suspended that uses the measured data of the specified fraction combustion point based on the current data when both of the first correlation index value and the second correlation index value are less than a determination value.

Methods and systems are provided for addressing spark plug soot fouling. In one example, a method may include alternating one or more combustion events with spark timing advanced with one or more combustion events with nominal spark timing. The approach allows spark plug over-heating, and related issues such as knock, to be reduced.

Feedback control is executed based on a measured CA10 and a measured CA50 that are calculated based on measured data for MFB. The measured data is corrected in accordance with a pattern of a waveform of measured data for a heat release amount, and measured data for MFB is calculated. A correlation index value showing a degree of correlation between the calculated measured data for MFB and reference data corresponding thereto is calculated. If the correlation index value is less than a determination value, control is performed to prohibit reflection in the aforementioned feedback control of each of the measured CA10 and the measured CA50 which are measured in the combustion cycle in which the relevant correlation index value is calculated.

A variety of methods and arrangements for improving the fuel efficiency of internal combustion engines based on skip fire operation of the engine are described. In one aspect the skip fire decisions are made on a working cycle by working cycle basis. During selected skipped working cycles, the corresponding cylinders are deactivated such that air is not pumped through the cylinder during the selected skipped working cycles. In some implementations, the cylinders are deactivated by holding associated intake and exhaust valves closed such that an air charge is not present in the working chamber during the selected skipped working cycles.

A method of limiting belt slip in a continuously variable transmission (CVT) of a vehicle. The CVT is operatively connected to an engine. The method includes determining a slip speed of a belt of the CVT, determining the accumulated energy based on the slip speed of the belt and an engine torque produced by the engine, and controlling the engine torque in an intervention mode when the accumulated energy is greater than a threshold energy. Controlling the engine torque in the intervention mode comprises controlling at least one of cycling the engine torque, and limiting the engine torque. Systems and vehicles for performing the method are also disclosed.

A cylinder control system of a vehicle includes a cylinder control module and an air per cylinder (APC) prediction module. The cylinder control module determines a desired cylinder activation/deactivation sequence. The cylinder control module also activates and deactivates valves of cylinders of an engine based on the desired cylinder activation/deactivation sequence. The APC prediction module predicts an amount of air that will be trapped within a next activated cylinder in a firing order of the cylinders based on a cylinder activation/deactivation sequence of the last Q cylinders in the firing order. Q is an integer greater than one.