Mondial QV misfire pop and bang

When mine started popping and banging, it was one of the coil packs breaking down. It started up fine but after a few miles it started missing- advice from dealer was to run car until it started missing, then jump out and compare the 2 coil pack temps by hand, if one was hotter - then it was heating up and breaking down. Temp difference was noticeable and once changed it was fine

 

Another factor creating pops and bangs on a K-Jet car is vacuum advance - more specifically, lack thereof. If there’s a vacuum leak on the hose to the Digiplex boxes, or the vacuum control of the Digiplexes has failed (either one or both), then the ignition timing will be quite retarded and there will be more unburned fuel exiting the exhaust valves when the throttle is closed on deceleration.

Gordon