This where WD-40 can do the job it was designed for. Spray down the dizzy cap and wires to get rid of any residual moisture. In your case it just dried itself out but some WD won't do any harm especially if where you are has damp misty mornings. The water mist spray when it is dark is a good trick and can be very revealing. You can get quite a firework display even when there appears to be no problems. WD can go a long way in curing that.