At this time of year in the UK, the likely cause of a mis-fire is the wet. Dampness in a car's electrical system can cause havoc, so a good spray of WD40 on your coil, battery, HT leads and distributor will work wonders, not only in protecting the system but in getting rid of the misfire.
This assumes, of course, your ignition system is in good condition and the car is regularly serviced. With the ignition off, check the HT lead are securely attached to both the spark plugs and the distributor. Likewise the lead from the distributor to the coil. Check too for signs of wear and, if dirty, clean them.
Another common cause of a misfire is the distributor cap. Check that the cap is not cracked, even a hairline crack is enough to cause problems.
Finally, if none of this cures the problem, the next suspect would be one of the spark plugs either working itself loose, being damaged, burnt out, needing the gap re-set or being missing.
This assumes, of course, your ignition system is in good condition and the car is regularly serviced. With the ignition off, check the HT lead are securely attached to both the spark plugs and the distributor. Likewise the lead from the distributor to the coil. Check too for signs of wear and, if dirty, clean them.
Another common cause of a misfire is the distributor cap. Check that the cap is not cracked, even a hairline crack is enough to cause problems.
Finally, if none of this cures the problem, the next suspect would be one of the spark plugs either working itself loose, being damaged, burnt out, needing the gap re-set or being missing.
