Provided herein is an optimizable hydrogen generation system for producing and injecting hydrogen gas as a fuel supplement into the air intake of internal combustion and/or diesel engines. Hydrogen gas (H.sub.2) and oxygen gas (O.sub.2) are produced with one or more pairs of cells to adjust the amount of hydrogen gas supplied to the engine, while the oxygen gas is vented to the atmosphere.

Provided herein is an optimizable hydrogen generation system for producing and injecting hydrogen gas as a fuel supplement into the air intake of internal combustion and/or diesel engines. Hydrogen gas (H.sub.2) and oxygen gas (O.sub.2) are produced with one or more pairs of cells to adjust the amount of hydrogen gas supplied to the engine, while the oxygen gas is vented to the atmosphere.

Provided herein is an optimizable hydrogen generation system for producing and injecting hydrogen gas as a fuel supplement into the air intake of internal combustion and/or diesel engines. Hydrogen gas (H.sub.2) and oxygen gas (O.sub.2) are produced with one or more pairs of cells to adjust the amount of hydrogen gas supplied to the engine, while the oxygen gas is vented to the atmosphere.

Methods and systems are provided for adjusting a throttle based on an intake oxygen sensor output. In one example, a method may include adjusting a position of a throttle based on a dilution threshold and a total aircharge dilution level, the total dilution aircharge level based on an output of an intake oxygen sensor. Additionally, spark timing may be adjusted based on the total aircharge dilution level.

Methods and systems are provided for adjusting a throttle based on an intake oxygen sensor output. In one example, a method may include adjusting a position of a throttle based on a dilution threshold and a total aircharge dilution level, the total dilution aircharge level based on an output of an intake oxygen sensor. Additionally, spark timing may be adjusted based on the total aircharge dilution level.

A method for reducing NOx emissions during operation of an internal combustion engine in commerce which, when burning hydrocarbon fuel as a primary fuel, in the absence of any secondary fuel, has a characteristic stoichiometric ratio. The method includes: in the absence of electrolytic activity, providing and entraining a quenching species in a gaseous medium; and then interacting the quenching species with constituents present during oxidation of the primary fuel in a combustion chamber of the engine.

A control device predicts whether temporary reduction occurs to a charging efficiency of fresh air in an in-cylinder gas by an influence of an EGR rate of the in-cylinder gas, which increases later than increase of a charging efficiency of the in-cylinder gas, if a first arithmetic operation is applied to calculating a target throttle opening degree based on a target charging efficiency which is increasing, in a case of shifting to an acceleration operation, by using a prediction model expressing dynamic characteristics of an internal combustion engine. When it is predicted that temporary reduction occurs to the charging efficiency of the fresh air, the control device calculates the target throttle opening degree by a second arithmetic operation by which an increase speed of a throttle opening degree is restrained more than by the first arithmetic operation, instead of calculating the target throttle opening degree by the first arithmetic operation.

An internal combustion engine includes a direct injection valve that directly inject gaseous fuel from an injection hole into a cylinder by separating a needle from a seat, and a blow-by gas treating device that recirculates blow-by gas from a crankcase to an intake passage. The control device executes a suction process of suctioning gas in the cylinder into an injection hole of the direct injection valve when the blow-by gas is being recirculated by the blow-by gas processing device.

An internal combustion engine includes a direct injection valve that directly inject gaseous fuel from an injection hole into a cylinder by separating a needle from a seat, and a blow-by gas treating device that recirculates blow-by gas from a crankcase to an intake passage. The control device executes a suction process of suctioning gas in the cylinder into an injection hole of the direct injection valve when the blow-by gas is being recirculated by the blow-by gas processing device.

Methods and systems are provided for adjusting a throttle based on an intake oxygen sensor output. In one example, a method may include adjusting a position of a throttle based on a dilution threshold and a total aircharge dilution level, the total dilution aircharge level based on an output of an intake oxygen sensor. Additionally, spark timing may be adjusted based on the total aircharge dilution level.