Slow acceleartion after rain

["c247852" <FSMinc@xxxx>]

I have a 6,000 mile Delorean I use only for running short errands 
and it always runs perfectly...except after a good Florida rain. 
When I go to start it, it fires up quickly and normally, but when I 
press the gas, it goes but it feels very sluggish, even as I 
accelerate through the gears. After awhile it starts to improve 
(presumably after the cars heat evaporates the troublesome water.) 
It does this even if the car hasn't been driven in the rain - in 
other words if its just been sitting out in the rain. When I open 
up the engine compartment it is dry as a bone - no water appears to 
be getting into the throttle where the air/gas mix? The only ports 
of entry for water appear to be where it is supposed to be open to 
the elements such as the side air intake by the far rear side window 
or the drains in the front windshield (maybe its getting into the 
gas tank through the worn out gas cap boot?) Maybe splash from under 
the car is getting in somewhere...but then again it does this if its 
just been sitting in the rain and not splashing through water. Any 
body have any ideas what's going on here? Thanks.