With that kind of mileage, I'd say with a decent amount of certainty that it is a fuel delivery problem. Start simple. Change the fuel filter and try it then. If it's still not fixed, then change the fuel pump. Also, just for good measure, I'd run a fuel system treatment through with a full tank of gas once you get things restored to working order.
Edit:
Just out of curiosity, has the car ever run out of gas? If it has there's a damn good chance you need a new fuel pump. Not to say that 189,000 miles is premature for a fuel pump failure, but it's a possiblity that if you've run out of gas once or twice, that you've shortened the life of the pump.
