I have a 96 S10 Blazer 4 Dr/4WD. It didn't want to start Wed after we had some rain. After killing the battery and a jump pack trying to start it, It took a jump from my brother to get it started. I had plenty of crank, just no start. It took like 45 minutes to start it. Started fine rest of day after that and Yesterday.
I go out this morning and it does the same thing. Plenty of crank, no start. It has been raining all morning, took 15-20 minutes this time. What could I possibly be looking at.

 

Give this a try--> turn the key to the RUN (not crank) position and wait 5-10 seconds. Then back OFF again. Repeat atleast 3 times, then try to crank the motor over. If this works, it is a fuel supply problem.

 

I tried this both times and got nothing.

 

Again, for clarification, the problem only exists in wet/damp conditions.

 

Moisture in the distributor cap?