So on my way home from work Friday I heard my serpentine belt fail within a mile and a half of getting home. I shut it down within a half mile or so when the temperature gauge got up to the red line, called my son and had him tow me home. Saturday morning I replaced the belt and the truck ran fine so I moved it from my shop to the house and parked it (75 yards). A little later in the day we used the truck to clean up some stuff around the property and I noticed it was running very rough and throwing a flashing CEL which indicated a misfire on cylinder 4. I unplugged the coil pack, removed it from the spark plug and then reinstalled it but still had the same problem. In an attempt to determine whether it was the coil pack itself or a problem with cylinder #4 I then swapped it with the #3 coil pack. The problem went away and the truck ran fine (still scratching my head about that).
Today right after lunch I went outside to move the truck and it wouldn't start. It would turn over just fine but sounded like it was firing at a distinct interval, such as on 1 or 2 specific cylinders. The fuel pump runs when you turn the key on, so that doesn't seem to be the problem.
A few hours later I again went out to try again, and now you can't hear it attempt to fire at all while cranking, although it still turns over fine. This truck normally has been quite reliable and I have put about 47,000 miles on it in the 2.5 years of owning it, being my daily driver. I do pretty much all of my own maintenance work and repairs as long as it's not too complicated, but I'm not a "real" mechanic. I really need to get this thing running but it has me stumped at this time.

 

Do a coil check on each one, pull the plugs out and ground them while cranking to see if they all spark - if you nuked a head gasket, you might get water out of a plug hole or two...hopefully not. If you have spark, then it's a fuel issue. Possible albeit unlikely for a belt to wipe out a ground or power lug on it's way around, but odd that it ran fine after the coil swap.

 

I did try squirting some ether into the intake while my son cranked the engine, but other than finally getting one small "pop" it wouldn't fire. I found it very odd that it was running fine when when parked yesterday but today it's simply dead. Is there a chance that the heat might have cooked the crank sensor and it "died" overnight?

 

Sorry, guys, I forgot to reply with the solution....
Fuel pressure - good
Compression test - good
Spark plugs - all of them were burnt to a gap of about 65-70 thousandths. Installed new plugs and she started right up, no sweat. They only had 37,000 miles on them, but HOW in the world do all 6 spark plugs simply and totally die while sitting in the driveway?