So I picked up an old f150 last weekend. It's the 300 inline 6 with 4x4. I was out doing some mudding and it was fine all day then I went through a few holes and it would cut off after. Then on the last one it didn't turn back on for about 20 minutes. My question is what would cause this to happen? I was thinking water in the intake but I don't know.

 

You might have gotten some water inside the distributor cap. Years ago, a buddy of mine would carry a can of wd40 in his old Jeep for that very reason. Water would splash up into the engine bay and kill the motor every once in a while. He'd just pop the cap off, spray it down, wipe off what he could, and head on down the trail. Thankfully mine was fuel injected with a dummy distributor.