Turbulent jet ignition engine misfire detection

A method for detecting a source of a misfire for an engine having turbulent jet ignition (TJI) during a service routine, the method comprising:

• coupling a diagnostic tool to an engine controller of the TJI engine, the TJI engine comprising at least (i) a first cylinder having a first main spark plug and a first pre-chamber having a first pre-chamber spark plug;
• and (ii) a second cylinder having a second main spark plug and a second pre-chamber having a second pre-chamber spark plug;
• commanding an increase in revolutions per minute (RPM) of the TJI engine;
• measuring an engine roughness and establishing a baseline engine roughness for the TJI engine while all cylinders are in an active state;
• commanding a first main spark plug to deactivate;
• measuring a first test engine roughness of the TJI engine based on the first main spark plug being deactivated;
• comparing the baseline engine roughness to the first test engine roughness;
• and
• determining, based on the comparison, whether the first pre-chamber is fouled.