Confirmed #2 by unplugging coil with no change to idle or running.
No fault codes.
New coils, new plugs.
Worth knowing that for about 20 seconds the car dropped another cylinder but returned to firing on 3 again. This has not happened again.
No smoke at all and engine still sounds mechanically mint, no knock not even a tick. just the rough 3 cylinder sound and the smell of petrol.
Spark plug comes out black and returns to silver with the rub of a cloth which makes me think it must be seeing some sort of ignition like a very weak spark from hidden electrical problem or extinguished by huge amount of over fuelling.
With no codes its pretty hard to figure out. At this point Im thinking a damaged tooth on the sprocket.
Any ideas?
v7sti bug eye
update: Under boost car runs alot better with the coil plugged in than without, but does not feel smooth, micro jerks felt. I'm thinking that the injector might be fire hydranting into the cylinder and making it null on idle but giving a weak combustion under boost. No smoke, sometimes 1 or 2 bangs when taking off in first gear from cold start. I'm gona try replace the injector unless anyone thinks otherwise?