okay try this. park the vehicle dry and when it starts raining go see if it will start. if not then I'm betting the windshield or weatherstrip at the hood is leaking down onto something. if it starts and then you go drive it and won't restart then I would guess water is flining up onto something in the engine compartment.. be sure the wondshield isn't leaking down on the panel.. it will do that.

 

The cowl is cracked pretty bad behind the hood maybe something is leaking there. I haven't found evidence of a leak. But I have a new cowl I'm going to install as soon as I get some help lifting the hood off. We are going to take a hose and do some more investigation today.
We were planning on taking this on a road trip soon. I hope to figure this out before the weather turns gloomy here. Winter is very damp and gray around here some years.
Hope to spend quality time on it next week.
Thanks for all the suggestions