Newbe here--having problems with our VolvoPenta 8.1 GI-G. Engine starts and idles fine--save for the fact that 2 adjacent cylinders are not firing,. Have used induction timing light to verify solid firing of six of eight cylinders--have swapped ignition coils from not firing to firing cylinders--no change so not coil. swapped spark plug lines from inactive to active plugs--no net effect so assume no spark plug wire defect. Nearest VP dealer 1.5hr away, and booked solid anyway. Kinda wondering if one can utilize a multimeter to verify delivered voltages to the ignition coil, although absence of timing light through a known functioning ignition coil kinda proves delivered electrical impulse is lacking. Control module?? any suggestions would be very appreciated. Thanks in advance SL