Pull the #3 plug and hook to wire and use a calibrated spark tester, grounded to valve cover bolt.
Look for a blue snapping spark.
A weak spark could cause the plug to gas foul.
All I was suggesting with my previous post is that when changing a WP, you can sometimes (unknowingly) disturb wiring connections or spill coolant on them causing a bad electrical connection.
Monday, September 21st, 2009 AT 9:16 AM