MX5 NB misfire and loose HT lead

[lmccl]

Hey folks! Need a little bit of help regarding my 1.8 vvt.
Was driving as normal last week when coming off a roundabout on an uphill the engine starts loosing power and misfiring with a flashing CEL that turned solid.

OBD scanner I had in the car showed P0303 cylinder 3 misfire and P0012 which had previously appeared and disappeared about a month ago after an oil top up that was also an attempt to resolve the lifter tick that's developed.
Opening the bonnet the cylinder 3 HT lead seems loose with about a mm gap compared to the rearmost lead and is not able to be pushed down and reseated again, the lead itself is also covered in soot.
(tried to post pictures to explain but don't have perms as brand new account)

The engine only seems to complain at lower rpm/under load, getting it up past 2.5-3k is grand but starting from stop is a chore for it.
Any ideas for next steps diagnosing this? Thanks!

[Bertrum]

Replace the HT leads. They don’t last forever.

Prob find the lead is arcing due to age, moisture and cold.

[Belle427]

Take the plugs out and have a look at them too, the one thats misfiring may be loose causing a bit of blow by.
Wont hurt to treat it to some new plugs and leads, dont go too cheap on the leads though as quality is always best.