I had the same problem on my Zetec recently. About a year ago I replaced the plugs and wires (Autolite Double Plats & el cheapo Bosch wires) had this problem about 3 months after. I pulled the plugs and scraped off the carbon tracks and put some Di-electric type waterproofing gel on the plugs. Ran perfect til' 2 weeks ago, the same little misfire hesitation showed up again. Pulled the plugs and the gel had dried up, carbon tracks on plugs again. Cleaned dried stuff off, scraped carbon off, regooped waterproofing di-electric into plug wire boots. Its purrin' again.
