think this might work? has anyone detected missfires by the time diferences between firing events? or on a crank angle sensor? in theory a dead cylinder should rotate the flywheel slightly slower due to lack of power stroke and slower again on the next compression.
Yes in theory this is possible, this is how the PCM or ECU's OBD system detects misfire. The trick is how to process/analyse the signal captured by the scope.
Here is an interesting article you might find useful,
Another method used to detect misfire is analysis of the oxygen or lambda sensor. A company that specialises in this is Thomson Automotive Labs in the US. This is their website,
The crank angle sensor tells the ECU the position of the crankshaft so it can work out when to fire the plugs and injectors. Its usually either an inductive or hall effect sensor located on the flywheel or on a pulley at the other end of the crankshaft.