[Rick Norwood]

If your hard starting problem comes and goes with the rain as you indicated, I don't think you're out of the woods yet. The outside of your cap will be dirty and the inside should be clean. Cracks in the cap can be hard to see. Did you notice any moisture inside of the distributor itself? A water drip from the heater hoses can certainly be a problem, but it should be all the time if the coil wire etc. are corroded, not just when it rains.

I have also had caps that don't seal around the bottom edge that seats on the distributor body. A light coat of grease around the base of the cap will help.