PREPARATION FOR SPRING RUN - Misfire

[Graham Dix]

How can one car have so many issues. Once starting well, coolant pressure sorted and clutch freed off …. time for a road test. All great for a few miles then a misfire which almost cut out the engine, then all fine followed by a repeat. I managed to get home intact and got down to problem solving.
From past experience my thoughts went straight to it either being the condenser or the coil although there can be many other causes including fuel starvation, wiring faults etc. I keep a spare condenser attached to a crocodile clip so that I can attach the condenser to the coil terminal leading to the distributor and the crocodile clip to a suitable earth. I road tested with this attached and the same misfire happened. By this time it was almost dark. Looking in the engine bay I could see sparking across the coil top to the metal connection of the oil cooler pipe. Early cars have the coil fitted very close to this. Misfire identified. I suitably spaced the coil as far away as possible within it’s confined space. Problem solved. See photo which shows proximity of coil to it’s surroundings. Do you have any misfire problems or solutions you would like to share?
Regards
Graham Dix
Chairman and Technical advisor