3.0 V6, hard to start when hot.

[cbxer55]

1998 two wheel drive Ranger 3.0 automatic.
Can anyone help me with a starting problem? It goes something like this.
It starts exceptionally well when cold, never a problem. But if I take it for a drive, then shut it off, it gets harder and harder to start as time goes by.
Example from timed testing I have done.
After 30 minutes it starts with a bit of cranking.
After one hour it requires more cranking, then stumbles a bit before settling down.
After 2 hours I can almost kill the battery cranking, eventually it will catch, then stumble really bad before settling down.
After 4 hours it is all but impossble to get running period.
Next morning fires right up.

Really got me on this one. I have good plugs, wires, one year old coil pack, one year old fuel filter. I bought a fuel pressure gauge, and my readings are 62 psi engine off, 66 psi engine running. I recently put on a new DPFE to replace the metal unit that was giving me a CEL. Have MAC air intake, JET chip and custom exhaust in front of right rear wheel. I have swapped relays to no affect.

The funny thing about this problem is I have had it before. It comes and goes, but I have never been able to nail down what is causing it. I would drive it to work, after 8 hours it would kill the battery getting it started. It would happen for several days to a week, then dissappear for awhile, only to return once again weeks or months later.

Symptoms are like this after sitting 4 hours.
Crank like crazy with very little effort to catch.
When it does catch, it seems like it is running on two cylinders, engine looks like it is going to jump the mounts.
After a few minutes, it seems like another cylinder catches, gets a bit smoother.
A bit longer another cylinder fires up.
After about ten minutes, it is sitting there idling like nothing is wrong.
Runs exceptionally well once going.
Plugs are whitish, as in lean. But they have always looked that way every time I change them. Bought the truck with 20,000, now has 100,000. Plugs have always appeared whitish, thought that was normal on computer controlled fuel-injected vehicles. As I said it runs exceptionally and gets good mileage, around 18 to 21 mpg normal.

There is no fuel smell at all. It seems it is not getting enough fuel when hot, yet a fuel pressure gauge tells me all is fine. What would cause a hot hard-to-start condition, yet allow it to fire right up cold? Any ideas out there? I have been fighting this problem intermittently for two years. It may stick around for another week, then be gone for months. Just cannot figure it out!

Thanks.