stalling trouble

I need some insight into a stalling problem that has been happening in my 95 jimmy. I live in Vancouver where it rains alot. When it raining my truck can stall out of the blue when i come to an intersection or just slow down. It sounds like it is running on two cylinders (like a TRUCK). everyone thinks that I am crazy cause i relate it to the rain or moisture in hte air, because that it the only time that it happens. Any ideas?

I'd star looking at the distributor cap and coil for cracks. Next time it's dry out, take a spray bottle with water in it and start spraying around the distributor and coil while the engine is running. It should start misfiring once you get the problem spot wet.