Cause of 95 V6 motor shuddering and dying

Truck sat undriven two months.  Driven very little in past year.  Battery died while sitting, jump starts OK.  Drove about 3 miles, started shaking, dying, barely made it back home. Symptom continued parked.  Has old gas in it.  Continues to start with no problem.  Fuel related?? Fuel pump dried out while sitting?  Fuel filter clogged?  The only good thing about it is I had just sold it and it started acting up on the buyer on his way home. He had driven it before, liked it, was satisfied, so the problem is his now.  Title is signed over.