The only thing I can think of is a jammed fuel line/filter from sludge at the bottom of the tank. I've seen this happen with a Ford... the car would stutter, sometimes die, cough, just run like crap. It was my girlfriend's sister's car, and she was a poor student and always put in just 2 gallons here, 1 gallon there, and ran it to empty every time. Ran out of fuel completely several times.
Now, when you're always taking fuel from the last 2-3 gallons of the tank, the concentration of junk goes way up. And yes, there is much junk in fuel. DOn't let the flashy TV ads tell you otherwise.
We changed the Ford's fuel filter and gave the girl a strong warning about always running on Empty, and the problem never returned.
If not that, then take it to a *reputable independent mechanic or dealer.*
Good luck,
M
