Oldsmobile/Buick Repair: 1988 Olds 98 Regency wont start after rain, water displacement, wd 40

Question
Van,
  This 20 year old car starts and runs like a top normally.  After being out all day on a rainy and cold day, it would not  start.  It cranks just fine ( has a new battery) and sounds like it is trying to catch but won't.  After letting it dry out for a few hours in the sun with the hood up, it starts and runs just fine again.  What would be the most likely cause?

Would using a waterproofing foam sealant around the connector wires be a good way of preventing this?  How can a mechanic know if he has a successful repair if the car normally does not have a problem starting?

Thanks for your usual great advice.

John

Answer
Hi John,
I would remove the distributor cap, and see if there is condensation inside it.
Spray inside it liberally with WD-40.
WD-40, actually stands for water displacement-formula #40.
You can even spray the outside of the cap, but I would sure look inside when it won't start.

Van