System and method for misfire detection for dual spark plug engine

A system for detecting a source of a misfire for a turbulent jet ignition (TJI) engine having a first ignition device disposed in a pre-chamber of a cylinder head and a second ignition device disposed for communication with a main combustion chamber, the system comprising:

• a controller configured to:
• determine engine operating conditions;
• generate a first spark from the first ignition device at a first time;
• generate a second spark from the second ignition device at a second time;
• activate a skipfire mode based on a determination that the engine operating conditions are satisfactory for maintaining Ion sense misfire detection while reducing main chamber spark plug wear, wherein the satisfactory engine operating conditions include a throttle position outside of wide open throttle, wherein in the skipfire mode, the controller is configured to generate the first spark from the first ignition device at the first time and generate a modified second spark at a modified second time, the modified second time being later than the second time;
• and
• determine a misfire event within an Ion sense window based on sensing ionization of gasses at the main combustion chamber subsequent to firing the first and second ignition devices at the respective first and modified second times.