shuts down then wont start HELP

I have a 93 Previa 2WD. I start it up in the morning just fine and let it warm up for about 15min. My drive to work is about 30min. Once I park and if left idleing for more than 5min it shuts down without any warning and then it won't start at least not until a few hours after cooling down.

I come out of work and it starts fine, then when I get home and I park it, let it idle for a few minutes and down it goes again.

Now I've been having this problem for about 2 weeks and two days ago I changed the fuel filter, spark plugs, wires, dist cap, oil change and it worked fine for two days.

Now keep in mind, it will not start if it shuts down on it's own but if I turn it off myself and will restart. How strange is that?

Can anyone please shed some light as to what the problem could be. I appreciate any help you can offer.

Thank you.

Check your Fuel Pressure with a Gauge, cuz its pointing that direction