16-05-2021, 12:51 PM
Hello Peter
If you had reported a general misfire and hard starting I would have advised checking the condenser (capacitor). When this is on its way out the available HT drops, and you get a misfire especially under load.
However, a problem only on 2 cylinders suggests something specific to those cylinders. This could be plugs, plug leads, distributor cap or lack of compression. The difficulty with a misfire from any cause is that it tends to soot up even an initially good plug, and eventually the conductive path resistance drops so low that the ignition system can't reliably produce a spark. In my experience this happens when it gets below about 100 kilohms. A sort of vicious cycle of misfire, plug fouling and worse misfire.
For this reason it sometimes helps to have a spare set of clean plugs, so that you can swap them all out before faultfinding further.
Having said all this, don't discount the possibility that the condenser HAS gone faulty, and this is just highlighting the fact that two plugs just happen to be more sooted than the other two.
If you had reported a general misfire and hard starting I would have advised checking the condenser (capacitor). When this is on its way out the available HT drops, and you get a misfire especially under load.
However, a problem only on 2 cylinders suggests something specific to those cylinders. This could be plugs, plug leads, distributor cap or lack of compression. The difficulty with a misfire from any cause is that it tends to soot up even an initially good plug, and eventually the conductive path resistance drops so low that the ignition system can't reliably produce a spark. In my experience this happens when it gets below about 100 kilohms. A sort of vicious cycle of misfire, plug fouling and worse misfire.
For this reason it sometimes helps to have a spare set of clean plugs, so that you can swap them all out before faultfinding further.
Having said all this, don't discount the possibility that the condenser HAS gone faulty, and this is just highlighting the fact that two plugs just happen to be more sooted than the other two.