Developed a skip a few weeks back and it was driving me crazy. At idle it was perfectly fine but cruising under a slight load it was definitely noticeable. Pulled the timer and it was clean (i run a TW) so i knew that wasn't it. Swapped out another set of coils i have, still the same. Checked all the wiring, seems to be fine. Pulled the 3 year old x's i have and they looked good but decided to pull them apart for a closer look and a thorough cleaning. This is what i found after cleaning them all up, it seems one had what seems like a carbon track in the porcelain. I can't see or feel a crack, but that might mean nothing. After replacing the plug with a spare i had, the skip is gone. Anyone else here seen this before?
Nope, but have a simular issue, but I had not started to look for it.
How old are these plugs? the old 1's had enamel or something else coating the interior porcelain and the newer 1's don't.The coated 1's were less apt to do this I think.
Good catch, plugs can be elusive because many look like they should run. I had a timer do something similar with carbon.
I use to have this intermittent skip problem with champion A(I think) 25's. I switched to Motocraft F11's, end of problem, that's all I use in all my T's now.
Jelf uses a lot of re-built plugs. Bet he's seen it.