Still trying to find
Join Date: Jun 2011
Location: United Kingdom
Check the intake pipe going into the manifold. Take it off and inspect it for cracks. It will be unlikely because if you did then you would have high fuel consumption and high RPM at idle.
It sounds like your getting a voltage leak from your coil pack? Check that the coil pack boot is properly seated onto the spark plug and the coil pack itself as you said the boot came off and was stuck in the spark plug hole.
As for you cleaning the spark plugs, as long as you didn't use a wire brush (and I'm guilty for doing this) then just replace with new plugs as mentioned by Dave, the gap between the plug centre electrode and the other earth conductor (bendy bit) looks a bit big of a gap.
Hope this helps