My wagon does the same thing when the fuel gauge gets below a quarter tank (need to clean fuel sending unit). The wagons' tank is lower than the sedans', so starvation happens more easily (someone correct me if I'm wrong). The intake screen could be clogged also. If you've run any biodiesel that screen could very well be clogged due to the cleaning abilities of the bio.

__________________
Brad
1981 300TD - daily driver
1963 Chevy II
2001 F-250 7.3 Power Stroke