Back again
Truck has been sitting for the past 10 days while I've been out of town. I went to start it tonight when I got home and we seem to have developed a no start issue.
Notes:
1997 F250HD 5.8L E4OD 2wd
Fuel pump does prime (audibly confirmed)
Engine cranks
No ignition
A few times, the engine fired a couple of times after the key was released (not before), but did not fire enough to run.
Truck ran perfectly when parked 10 days ago
It has been raining, i have a messed up hood, both sides of the engine bay are damp (its been raining hard). - distributor cap is dry

I'm thinking this is an ignition issue or a wet computer issue, but i dont know where to start looking, any help or thoughts are welcome!

 

Sounds like no on/off signal from the PIP/ICM to the Ignition coil.
Put a test light on the NEG (-) side of the coil as it cranks to check this. It should flash.

 

Flooded?
Put your gas pedal all the way down, floor it, wide open throttle(WOT), and that will put the computer into flooded mode, and will not inject any more fuel.

 

Update. Went out to troubleshoot the truck this morning, it fired up right away and ran and drove fine all day today. From what I've been reading, I feel like this is a ICM issue. Thoughts?

 

Reviving my dead thread. Truck has been driving great the past two months, I haven't changed anything in the engine.

Sunday I went to change the radiator. While I was flushing the system, a "little" water was spraying on the fan, and the engine bay got a bit of a mist over it. Shortly after, the truck began running rough and blowing white smoke (no, I didn't blow the head gasket, I already (panicked and) checked.). I shut the truck off, and went to restart and it exhibited the same symptoms as before. I tried changing the ICM (I bought one after this issue last time and had it on stand-by) and there was no change.
Monday, I put the old ICM back, the truck fired up on the first try.

What I've observed is last time this happened and this time is that both times, the truck was in "high humidity". The first time, it was 80 - 90% humidity and raining. The second time, I misted the engine with water. Both times, the truck was running fine again after 12 - 24 hours during drier conditions. These symptoms are also reminding me of when i was young(er) and dumb(er) and I hosed off my engine compartment and filled the distributor with water on accident. Is it possible the high humidity/dampness is causing this issue, or that my distributor is worn to the point that its allowing this to be an issue? Alternatively, could it be the ignition coil itself that's the issue?

 

Could your distributor cap have a crack in it? I've heard of that causing an issue by letting moisture in.

 

I have seen the condition of my truck. Yes. It's very possible.

 

Same issue as before. Truck ran and drove on Friday, it rained all day Saturday and now, Sunday, it won't start.

My first thought was the distributor getting moisture in it, any thoughts on how this one looks?

 

That cap and rotor are completely shot. Replace them. That's not moisture, that's just being worn the heck out.

 

Good to know. I have never replaced a complete distributor in one of these before, and I don't know much about advancing or retarding the time to be correct. Does anyone have a good thread to point me to

 

Why are you talking about replacing the whole distributor when you only need a cap and rotor?

 

I presumed it would be best to replace the entire unit, seeing that the cap is loose and the clips are rusted. Is that not the case?

 

Also, I went out to the truck just now and it fired right up. It's definitely affected by the humidity or the recent rain.

 

No, it's pretty rare to replace a distributor, unless you lose one of the shaft bearings, or some such. Given the condition of your cap and rotor, it's not surprising in the least that it acts up in humid weather/after rain.

 

Thanks, you just saved me $100, provided you're right. Do I need to be concerned about the clip-arms being worn out, or should they probably be fine.