I was going to suggest that AJ's problem was likely with plugs & wires. I had the same symptoms in my V-6 and fixed it that way.
Also helped another CEGer with an Zetec with this issue, his was plug wire related as well. His plug insulators were actually shattering because the misfire was so violent. Motorcraft or Autolite wires & Motorcraft plugs should get you guys on the road. Replace them all at the same time with new stuff.
