So i have a combination of problems I could use some wisdom on.
Was doing a maintenance oil change, after which i started getting a consistent misfire... old oil smelt strongly like fuel so some research advised me to swap in some brand new rx8 injectors i had spare, while i was at. During the injector swap the intake mani had a fair amount of oil in it. My intro post here taught me that this is down to a PCV issue, checked the valve, slipped right out, the end that sits in the valve was coated in oil, Gave it a shake and it still rattles at room temp. So my logic here is that the pcv set up was sucking in oil, thinned by the fuel, into the intake and into the cylinders. Cylinder 1s plug is covered in oil, others look healthy thankfully, but it explains the miss to a degree.
So my solution theory here is:

• Re-route PCV to catch can and vent to atmos and block off the 10mm intake port (for the time being)
• use breather filter on the exhaust side.
• replace PCVto be safe
• clean the oil out the mani
• clean the oil off the oily plug
• compression test
• leak down test
• drink bleach if it doesn't work

Am i missing anything from my logic here?
Also is their any DIY trick to clearing the oil from the misfiring cylinder?
relevant specs:
1.8 mk2, Stock intake mani, MS2, Rx8 Denso yellows 420cc, Impreza TD04, NGK bk7 plugs, Jackson racing spark leads.

 

I think compression/leakdown should be the first step. Also, check plug leads, could just be a bad wire if it came up suddenly.

 

Thanks for the input man, I lack the kit for the tests which is why it is further down, in actual fact, workshops local to me didn't even know what a leak down test was... found a shop out in the sticks that caters to performance prestige vehicles that has me covered though but will have to wait til pay day..

I completed PCV the re-route and started it up today n found my idle and boost gauge readings were off, gauge was fluctuating between -9.9 and -7 and giving it gas and snapping shut would make the idle almost drop low enough to stall, so i am thinking the PVC set up to atmos doesn't configure well with my vac line set up. i currently have my extra vac lines (ECU, BOV, boost control solenoid) running from the nip just above the TB. All threads on here generally recommend to tap in to the FPR line. So i may Try That.
Still need to clean out the Mani. Crank seals piston rings and Head gasket were all replaced like 3 years a go, so less likely culprits to come up on the tests but not resent enough to be impos by any stretch.

 

None of this stuff is related to your pcv

I have both valve cover vents going to a vented catch can, without a pcv valve and it's running great

 

I am just saying the oil in the intake mani was pcv related as i was running the pcv valve to the intake mani with filter on the other port, which is why i redirected the pcv to a catch can etc to elminate that from being a problem, taking the advice of the numerous threads on their setups. Are you suggesting all the issues aren't linked to the misfire?

 

So i replaced the spark leads and no misfire, awesome, move the car to flat ground to do oil change, notice the Afr gauge going lean every so often when idling like 18-20 then going back up to 14, hoping its just got some flat spots for being undriven for about 2 months and having the injectors changed? or could be fuel going bad? Tried to drive it up on to 2 bricks to save me having to sit it on axle stands, clutch ******* noped out, slipped went spastic shaky, took my foot off the gas n it sat idling peacefully. Ended up just jacking the car up there n doing it on stands. oil filter is stuck on tight so have to wait til tomorrow to get a grip from a friend to crack it. haven't started it since hope i haven't melted the clutch weathers top down worthy and im missing out on some prime driving time...

this is getting on my nerves