1995 F150 won't start in wet weather
 

Hello,

My son has a 95 F150 with the 4.9 6 cyl.. This truck runs great all of the time except when it sits all day during a steady rain. It will turn over fine but just won't start. We have owned this truck for over 6 years and it's done it for a long time. I remember him running through a big puddle during a rain storm and it doing this. Seems like if I would crank on it pretty hard off and on it would finally start but would run rough for the first 30 seconds after starting. I initially replaced the distributor cap and rotor button but that didn't help. Can't remember if I replaced wires or not but thinking I did. He is in the Marine Corps and was away for 4 years and it pretty much stayed in our garage so I stopped chasing the problem. Now he is back state side and driving the truck again.

Question is if the obvious Distributor cap, rotor button, plug and coil wires doesn't fix it then where to look next.

Look for a cracked or carbon tracked coil.