It seems that the Pacific Northwest rain period causes my van to hard start.

My final solution is to replace the distributor cap and rotor and spray the ECU and Flowmeter plug and inside the Flowmeter.  

After sputtering and blowing out carbon the van seems fine.

Why is this the way it is?  Is this common?

Also it seems that the van is suseptable to low or no spark.  Since it is working I am not a fan of replacement, but is there a part that needs replacing?