Method and system to detect spark loss in a multiple spark plug per cylinder internal combustion engine

A method for controlling a multiple plug per cylinder internal combustion engine to detect spark plug misfire, the method comprising:

• modifying relative ignition timing between or among spark plugs associated with a particular cylinder to determine whether one spark plug's contribution to crankshaft angular acceleration is significantly different from the remaining spark plug(s)' contribution to crankshaft angular acceleration associated with the particular cylinder without disabling firing of any of the spark plugs associated with the particular cylinder.

A method for detecting spark plug misfire in a multiple cylinder internal combustion engine having first and second spark plugs associated with each cylinder, the method comprising:

• firing the first spark plug associated with a particular cylinder;
• and
• subsequently firing the second spark plug associated with the particular cylinder to allow monitoring of crankshaft rotation associated with the firing of the first spark plug to detect misfire while still initiating combustion within the cylinder when the first spark plug misfires.

A system for controlling an internal combustion engine having a plurality of spark plugs associated with each cylinder, the system including an engine controller in communication with the plurality of spark plugs, the controller comprising:

• instructions for modifying ignition timing for all but one spark plug associated with a selected cylinder;
• and
• instructions for monitoring at least one engine operating parameter to determine whether the one spark plug is misfiring.

The system of the engine controller further comprises:

• instructions for repeatedly modifying ignition timing and monitoring at least one engine parameter for each of the plurality of spark plugs associated with the selected cylinder.

A system for detecting spark plug misfire in a multiple cylinder internal combustion engine having at least two spark plugs per cylinder, the system comprising:

• a sensor for monitoring crankshaft rotation to detect a cylinder misfire in which all spark plugs associated with a particular cylinder misfire;
• and
• a controller in communication with the sensor, the controller selecting a first cylinder and a first spark plug associated with the first cylinder for testing during a first combustion cycle, firing the first spark plug, monitoring crankshaft rotation associated with firing the first spark plug to detect whether the first spark plug misfired, and firing at least one of the remaining spark plugs associated with the first cylinder during the first combustion cycle, wherein firing of the at least one remaining spark plug initiates at least partial combustion within the first cylinder in the event that the first spark plug misfired.