Section 03-07A: Ignition, Distributor
1997 F-Series with Gasoline Engines Workshop Manual
CLEANING AND INSPECTION

Spark Plugs

  1. Clean spark plugs (12405) as necessary using a wire brush or professional spark plug cleaner (follow manufacturer's instructions).

  1. Inspect the firing tip. Replace spark plug if firing tip is worn or damaged. Refer to following Spark Plug Inspection Chart.

Spark Plug Inspection Chart