Ok experts, I know someone out there has the answer so please help a girl out. I searched all I could find on the forum and Google but couldn't find the answer so am posting here.

1992 ES300 - 182,000 mi in Arizona.

It starts fine in the morning (or after sitting 4+ hrs)

It runs fine when driving.

If I run it long enough to warm up (15 min or so) then turn it off,
it still starts right up IF I restart it immediately.

But after it sits, for over 15 minutes or so, then it wont start.

It cranks easily but won't even give any feeling that it's trying to start, just cranking over.

Then it has to sit and rest before it will start again. When this first started, it only took 20 minutes or so but has gradually increased to 3+ hrs before I can start it again.

A guy I know sprayed starter fluid in the intake and was able to make it run for a little bit before it died again and he said it's a fuel problem.

So, it's been to a mechanic (but not at all a Lexus / Toyota expert) who can't find the problem.

This has been tried:

A new fuel pump (with new strainer/screen)
new fuel pressure regulator
new fuel filter
new ECU / computer
new coolant temp sensor
new green and gray (or blue) (1 each)
ported vacuum switches that are down under fuel regulator

new ignitor (I think)
coolant filled and radiator caps replaced
several hoses replaced
oil topped off

the distributor was replaced a year ago with a re-manned and is under warranty.

And it still does the same thing. I saw on the forum someone talking about fuel pump relay and ask my mechanic about it, he said it didn't have one.

So, I am at a loss and would appreciate any help you can offer.

Thanks so much!