Can't wrap my head around this... Last year had to replace the head on the Focus, got it back on the road in November. I did reuse all the spark plugs since they were new. All was good till March this year, whenever it sets or rains it will not start. This time all the spark plugs but #3 was wet. #3 was a spark plug from a prior change couple years ago. I found another from the same change and went through and checked spark on all four wires with this spark plug, placed it on the edge of the valve cover. Spark on all four cylinders with that spark plug. Next was testing each plug. The plug from the other change sparked right away on the valve cover. The 3 other newer plugs didn't initially fire on the valve cover so put them on the radiator support and then they fired there and then they fired on the valve cover, I think the only difference is the new ones are double platinum's the older ones are regular platinum's. Both Motorcrafts. Interesting to see the spark along the electrical path. So I put all the spark plugs back and it fired right up, misfired some but finally cleared up. It'll probably run for weeks without issue now. I can't find the other two older plugs or this would be simple. I hate throwing parts at this thing but is it as simple as spark plugs? Just seems odd. I tried another coil, tested the wires before my help came home and still wouldn't start, compression is good since I know that'll be asked.