My saph has developed a misfire under load. It started when I was driving back from silverstone classic in torrential rain.

I checked the three connectors at the back of the engine bay and found a small amount of water in the middle plug. I have left this plug disconnected all week to let it dry out and have also replaced my ignition coil, put in a new wiring loom for it and replaced three ht leads (got three used ones with the car). I have also cleaned the crank position sensor which was a bit gunked up and checked my distributor and rotor arm which both look fine (they were replaced fairly recently).

The car is still misfiring above about 3000 revs, I am going to get a new set of spark plugs and leads but am fairly sure, from reading old threads on misfiring issues, that the cause of this was water getting in to that middle connector, i'm going to spray some wd40 in it to try and disperse any remaining water but after doing this I'm not really sure of the next course of action. Does anyone have any advice that might help me sort this out?