1988 Silverado k1500 z71 - runs great, for a few minutes.

[rkrizan]

I have a problem with my pickup. It has a relatively fresh motor, with only 30,000 on a crate engine (350CI/TBI). It ran great for about 2 years of use. The other day, I started it up to do some hauling and I left it to idle for about 5 minutes before I moved it, which I normally do, however, it started idling higher and higher and the check engine light came on. I figured the automatic choke was stuck or something, and at this point the engine was at proper operating temperature anyhow so I tapped the throttle to bring it back down. The truck starting choking and it died, and would not restart. It wouldn't kick at all, as if it was starving for fuel. So I checked the plugs, they had a little carbon on them, so I replaced them, along with the cap, router and wires. Of course by this time the engine was cool again, so it fired right up. I again let it sit for a few minutes, and it did the same thing. I let it cool for a couple hours, pulled the oxygen sensor, cleaned it off a bit, changed the air filter, checked the map sensor plug, and even tested the map sensor, all seemed fine.

This time, when the engine was cool, I started it up, and immediately took it out on the road and opened her out, thinking maybe she needed her throat cleared, ran great, until it got to proper temp again. Got it back to the yard, she died, refused to start. I'm kind of lost, as I've tried tracing down any electrical problems, replaced several parts, etc. Any of you know what I might be missing? I know chevy engines like the back of my hand, so any help would be much appreciated. The only thing I haven't checked is the computer, however from what I'm told once a computer goes, it goes.

I've just recently replaced the fuel filter, and pump as well.

Thanks