95 Blazer: What next?

Ok, I have gone through many proccedures from the various advice on these posts.
Wires replaced, new plugs, changed oil, cleaned the EGR, adjusted throttle sensor(atleast I think)
Last night I disconnected the computer and reconnected today,
Started the truck, it idled like a dream, stepped on the gas and the rpm went up smooth returned to a smooth idle.
Backed it down a slopping driveway, put it drive, no accelarition, no power, brought it back up listened to a smooth idle in neutral stepped on gas rpm goes up engine accelarates, within 7 minutes of idling, (this is the 3rd time it has done this) there is a whining noise from underneath and the the egine idle drops and the engine stops.
When you try to start it again it turns over and wont start. Leave it for a 20 minutes and it starts again but let it idle and it'll repeat,
Acclerates great, idles smooth in neutral or park but after 7 to 10 minutes of running it dies ,, Ohh the whining sound goes on for a couple seconds after the engine dies and sounds like its coming from underneath, are of the exhaust or catalytic convertor.

Yepp sure enough, just tried it again, no accelarating power, smell of gas at the exhaust , just a smooth idle in park and rpm goes up smoothly.

Check the cat, does it rattle? Mine broke up inside and parts of it blocked the exhaust pipe so it had no power...

//Frehol

Update,, with all the threats of it being the fuel injection system I took the plenum off, which did not take all that long and easier then it appears I see a puddle of gasoline.
Had my son turn the key on start, without turning over engine and sure enough the fuel pressure regulator was pouring gas out.
The price for a FPR is about $55 and $14 for a gasket for what was quoted as a $1000 dollar repair bill.