Fouled Plugs - Pic Included!
 

Ok, so I am wondering whats up with the top right plug (pulled from the front passenger side cylinder).. I think it is strange that the "goo" doesn't completely cover the plug.. I am guessing the ring in that cylinder is trashed, but it is definately getting a spark in there now.. I was getting a mis-fire when first started for about 10 - 15 seconds.. Now I know why..

I am not sure if/when they ever changed the plugs on this truck before.. They all came out easy (did them when the engine was hot)..

http://stonedplanet.com/images/plugs.jpg

oh yea.. specs:

1997 F-150 4.2l
2wd

Except for the lower left plug they really don't look that bad they worn to be sure but you have the nice gray
look of a proper fuel mix and they are not oil fouled. You could clean regap all but that lower left plug and
but them back in if you are short on money. Spark plug are cheap so replace them all

i think your goo is oil. the one closest to the oil fill cap does that on mine. or you might have a bad ring. but other than that they look really clean. motorcraft plugs are about 1.99 or 2.99 if i rember right not to much.

That one plug guessing driver rear has oil on it. The plugs are not that much, I priced them the other day. I think motorcraft was 2.xx a plug.