Systems and methods for operating an engine that may be rotated by an electric machine during engine starting are described. In one example, an amount of electric current that is available to rotate the engine via the electric machine may be adjusted in response to an indication that a vehicle that includes the engine may be parked in a geographical area that may be flooded.

Provided is a discharge stopping device for stopping a spark discharge during discharge, including an ignition plug, an ignition coil, a power source device, a first switch, and a controller which causes a spark discharge to be generated by controlling the switching of the first switch, the discharge stopping device further including a second switch which is disposed in a current circulation path connecting both ends of a primary coil of the ignition coil and switches the current circulation path between connected and disconnected states, wherein the controller includes a re-energization control process unit which switches the first switch to a connected state and re-energizes the primary coil with current during occurrence of the spark discharge, and a circulation control process unit which switches a second switch to a connected state and sets a current circulation path to a connected state during occurrence of the spark discharge.

Provided is a discharge stopping device for stopping a spark discharge during discharge, including an ignition plug, an ignition coil, a power source device, a first switch, and a controller which causes a spark discharge to be generated by controlling the switching of the first switch, the discharge stopping device further including a second switch which is disposed in a current circulation path connecting both ends of a primary coil of the ignition coil and switches the current circulation path between connected and disconnected states, wherein the controller includes a re-energization control process unit which switches the first switch to a connected state and re-energizes the primary coil with current during occurrence of the spark discharge, and a circulation control process unit which switches a second switch to a connected state and sets a current circulation path to a connected state during occurrence of the spark discharge.

An engine automatic stop/restart device includes an ignition-prohibition-decision unit that prohibits an ignition for an engine, which is controlled by the ignition-control unit, when a reverse rotation of the engine is detected based on a crank-angle signal; and an ignition-prohibition-release-decision unit that releases an ignition prohibition, after the ignition is prohibited by the ignition-prohibition-decision unit; in which the ignition-prohibition-release-decision unit releases the ignition prohibition when regular rotational signals of the engine, of which count is greater than or equal to a predetermined count, is detected and an engine revolution number is greater than or equal to a predetermined revolution number, after the reverse rotation of the engine is detected, and before a crank is positioned at a compression top dead center of the engine.

An engine automatic stop/restart device includes an ignition-prohibition-decision unit that prohibits an ignition for an engine, which is controlled by the ignition-control unit, when a reverse rotation of the engine is detected based on a crank-angle signal; and an ignition-prohibition-release-decision unit that releases an ignition prohibition, after the ignition is prohibited by the ignition-prohibition-decision unit; in which the ignition-prohibition-release-decision unit releases the ignition prohibition when regular rotational signals of the engine, of which count is greater than or equal to a predetermined count, is detected and an engine revolution number is greater than or equal to a predetermined revolution number, after the reverse rotation of the engine is detected, and before a crank is positioned at a compression top dead center of the engine.

The present invention relates to a method, system, and computer program product for controlling an internal combustion that comprises a cylinder having a space arranged to receive air and fuel, a piston disposed in the cylinder, and a crankcase being in fluid communication with the cylinder. The method comprises determining an uncontrolled behavior due to fluid flow between said crankcase and said cylinder space and combustion of such fluid. The step of determining an uncontrolled behavior comprises the steps of: determining whether a powertrain of the vehicle is disengaged; determining whether the engine speed is increasing; and determining whether said cylinder space is receiving fuel. The method further comprises determining that an uncontrolled behavior is occurring if the conditions that: said powertrain is disengaged, the engine speed is increasing and said cylinder space is not receiving any fuel, are fulfilled.

The present invention relates to a method, system, and computer program product for controlling an internal combustion that comprises a cylinder having a space arranged to receive air and fuel, a piston disposed in the cylinder, and a crankcase being in fluid communication with the cylinder. The method comprises determining an uncontrolled behavior due to fluid flow between said crankcase and said cylinder space and combustion of such fluid. The step of determining an uncontrolled behavior comprises the steps of: determining whether a powertrain of the vehicle is disengaged; determining whether the engine speed is increasing; and determining whether said cylinder space is receiving fuel. The method further comprises determining that an uncontrolled behavior is occurring if the conditions that: said powertrain is disengaged, the engine speed is increasing and said cylinder space is not receiving any fuel, are fulfilled.

An engine control device includes an electronic control unit. The electronic control unit is configured to perform a spark discharge with an ignition plug for each cylinder by cutting off energization after elapse of a predetermined period from start of energization to an ignition coil for each cylinder of the engine, to stop the spark discharge caused by the ignition plug for each cylinder after supply of fuel to the engine is stopped when operation of the engine is stopped, and to control an ignition plug so as to stop the spark discharge caused by the ignition plug from a cylinder after a rotation speed of a crankshaft decreases gradually and the rotation speed of the crankshaft reaches a preset threshold value or less, after the stop of the supply of fuel to the engine.

An engine control device includes an electronic control unit. The electronic control unit is configured to perform a spark discharge with an ignition plug for each cylinder by cutting off energization after elapse of a predetermined period from start of energization to an ignition coil for each cylinder of the engine, to stop the spark discharge caused by the ignition plug for each cylinder after supply of fuel to the engine is stopped when operation of the engine is stopped, and to control an ignition plug so as to stop the spark discharge caused by the ignition plug from a cylinder after a rotation speed of a crankshaft decreases gradually and the rotation speed of the crankshaft reaches a preset threshold value or less, after the stop of the supply of fuel to the engine.

A method for preventing back fire of an engine by a device for preventing back fire of an engine, may include monitoring operating information of the engine; determining whether the back fire occurs by using the operating information of the engine; and controlling an ignition timing to be retarded when the back fire occurs as the determination result.