2001 Ford Ranger rough start and sputters out?

Lot o' miles. One day i went to move it after it sat for maybe 2 days. When I came out about 20 minutes later, it had trouble starting. It was cranking, not catching, or it it did it would die. Got it started, ran it for maybe 20, everything acts ok again. A while later it sat for about 4 days. Started with the same trouble. Died when i tried to put it in gear. Today it started great, but then was like it wanted to die, especially at lower rpm (anything below 1000)

oil looks normal, doesn't seem to be smoking, no overheating
one day i went to check the radiator and fluid shot out when i took the cap off, making me think its a head gasket. But then i wonder why after sitting long enough to get cold why the pressure wouldn't have dissipated, gone through the overflow etc?

i went to the forums where someone said they had something similar happen and they replaced PVC elbow. I was wondering about sensors or something as i had a truck once that would stammer at lights because of that.

Sounds like a bad vacuum leak or maybe your mass airflow sensor to me. Could be the map sensor too

A misfire or intermittant miss, lean miss.
A fuel pressure or volume problem. Regulator.
Tune-up parts etc.
The tests have to be run before you start condemming parts, the inspections have to be made to be sure it was not worked on or tampered with while sitting.
Sample the fuel, measure the volume. Let it sit in a jar.
Run pressure tests and spark tests, see what you are losing when it dies, do your maintenance you know you are behind on, the problem may just present itself. You could have wires arcing or a pluggy throttle air bypass valve, or just good ol fashioned weak fuel pressure.
For all you know, dennis peed in the gas tank.