Wet Fouling all cylinders (RB25DET)

Hello! This is my first introduction here, im glad to be part of the community!

I drive a Nissan Skyline R33 GTST which has given me trouble recently.I’ve had my car in the garage for 6 months now, during winter time.Before I put it off I had the car remapped.During the mapping session the car suffered from intermittent missfires on higher rpm.Then when I was done and started the car to drive home the car only ran on 5 cylinders.We did some fault searching, narrowed it down to cylinder 3.Then all of sudden after we swaped coilpack 3 & 1 around, it worked again.The coilpacks used at the time were Splitfires (5 years old).One of the things I wanted to dowas to upgrade the ignition system, so I did. Installed VR38 smart coils. Also swapped out the sparkplugs (ngk bcp7res) gapped at 0.7mm.This is when I found out that all of my old sparkplugs were very black and a bit wet/moistyI originally thought this was a tuning or fuel realated issue since it was affecting all the cylinders.

I did a compression test days before the mapping seassion the sparkplugs were fine then.This week I started her up.after about 40 minutes of total running at idle (mostly idle due to tapping noise from the lifters, which went away after about 20 minutes of warm up). I removed to check my new plugs..All the sparkplugs have what to me looks like fresh engine oil on them. The threads are clean, it’s just on the base and partly on the center electrode, just as the previous ones too had.My sparkplugs have never looked like this before. Do you guys have any idea what would cause this all of sudden?

The car dosn't smoke unless I coldstart it in cold/moisy weather. Never needed to top up the oil.

AFR sits at 12.3 when cold then between 14.5-14.7 when warmed up.

Will upload some pictures so you can see too.

I’ve checked the settings in the power fc. The injector data seem correct.

(66% correction, 18msec latency)

Nismo 555cc side feed. (0.71ms latency)

Stock value: (370cc 0.52ms)

Injector duty cycle at idle is between 1-2%.

Highest value achived when cranking was 5%.

AFM reading: 1320mv @idle (cold)

Checked my intake piping and catch can for oil deposits, can't find any.

The car is a R33 RB25DET, I run the car on 98 octane petrol.

Car has uprated turbo,injectors, fuelpump, maf,ebc.. Running a apexi power fc.

Unopend engine done about 90000km.

Hello this looks more like oil sitting in the spark plug hole and getting onto the spark plug when it has been removed. maybe some oil has been spilt when adding oil or the rocker cover is leaking but first, check for that as it is unburnt oil.

if that i not the case then a cylinder leakage test will be needed,