Heres the deal..

Tried new plugs.. new wires. Plugs are gaped to .035".

I have a intermitent idle misfire that I can't seem to cure. My wideband also shows 17:1-20:1 at open loop idle because of this misfire which I am sure is caused by the 'flashover'. Which in turn tricks the wideband into the so-called 'phantom lean' condition.

At night I can see a spark going from the edge of the spark plug boot to the nut on the spark plug. This isnt the glow that some people talk about on the boot because I can actually see the spark.

This is a new engine that isnt winter driven so there is no corrosion on ground wires. The ground strap from the back of the head is bolted to the firewall with the coil bracket bolted to the same bolt.

Any Ideas?
thanks

 

The electrical current will always take the 'path of least resistance', so I would guess that the plug gap is too wide or it is a bad plug. I had a similar problem with my coil arcing from the coil wire boot to the base of the coil contact causing a misfire. It turned out that I had a corroded cap and so the path of least resistance was to the base of the coil contact.

 

Its arcing on all of the plugs/wires.
Brand new RC12yc and did that with my NGk's too and with my rc12yc's before that. Plugs are gapped at .035". Distributor is new, along with the cap and rotor.