You gave me info on changing fuel filter on 91 Ford Escort, 1.9L, earlier today and I plan on doing that tomorrow but I neglected to say that the car died while I was driving it; the engine just slowly wound down til it stopped running, even though I was pushing the gas pedal. The fuel pump was replaced by a friend about 4 years ago and ever since or soon after, it started making a noise when the tank gets down to 1/2 full and continues to do that until I put more gas in it. It's a low, humming kind of whining noise that hasn't been loud enough to make me want to investigate it and since the car was running okay, I wasn't that concerned about it. Given that info, do you still think it may be the fuel filter that caused it the engine to just stop running or could it be the fuel pump instead? Also, if you still believe it could be the fuel filter, is there anything we need to do since we can't run the fuel out before we change the filter?
Before anything, have you checked to make sure the engine is getting spark? Do this. See if the engine will start and run a couple seconds with starting fluid. If it starts, then you have spark and the fuel system is the issue. As far as the fuel filter / pump, the noise you heard was most likely the pump running. It may have just been easier to hear when the fuel was low in the tank.
Try the starting fluid so I know for sure it is a fuel related issue, and let me know what you find.