F-150 cold start problem HELP!

I have a '95 F-150, w/ a 5 L engine. approx 240K miles. the truck has been fantastic, untill recently. only after sitting overnight , it will not fire. turns over fine, and it's a hit or miss problem.

It really feels like a condensation problem, as after it starts, I can trust it all day.

I believe it's not fuel as ether doesn't help, and there is pressure at the rail.

I have replaced,... coil, ICM, O2 sensor, TPS, temp sensor, cap/rotor, swapped relays, unplugged/plugged every connection I could find.

before I put a bullet thru the block............. can anyone give me ideas?

UPDATE;
this truck has an Electronic trans.. this morning, when trying to start, it fired while holding the gear selector full up, past Drive. could this be condensation in the steering colum? is there a switch (N safety type) that could be the culprit?
Removed ECM, cleaned contacts, etc.. started 1 day,.. today, no start.. I hate to pay $200 for a new ECM, without knowing I've checked everything else out!

first, I'd like to thank everyone for the deluge of responses to help.
after replacing almost everything except the ECM, I replaced the distributor.
The truck DID start today, so if it starts 2 days in a row I'll concider the problem gone.
Hopefully, if someone is having the same problem, my post will help.