Ford Repair: 1990 cougar, path of less resistance, distributor caps

Question
Hi Steve! Hope you can help! I have a 1990 Cougar and if it sits in the rain more than 6 hours it will not start! I have replaced the cap and rotor ! The car runs like a champ when it is dry no misses and idle's where it should! I have to start it on a rainy night before bed and then 1st thing in the morning start it! It runs perfectly in the rain also! Please help!  Thanks John Ps.   Somebody told me there are vented distributor caps and I could have a cheap cap! Also I checked out wires at night and no sparks and besides that If plugs and wires were bad it would do it all the time!

Answer
John-

  Actually, it could still be the wires.  A lot of the time if the insulation around the wires is just starting to wear away the spark will only jump in the precense of moisture.  The moisture provides a path of less resistance and the current takes that path.  A slightly more accurate way to test would be to run the car at night (or in the dark) and use a spray bottle set on mist to spray around the wires.  Even if it's not the wires, it's almost definitely electrical since it only happens when moisture is present.  The spray bottle method can also work in other areas of the engine since it can be fairly localized.  Just wait until everything is dry and spray in a particular area (one place at a time) until you get the car running bad.  Then you'll have a much better idea of what's causing the problem.  Hope this helps.

Steve