I had a simmilar problem with my 00-SVT (75K miles) and resolved it with a new fuel pump ($259 from Ford dealer)
my symptoms were:
1/4 tank + left hand turn + acceleration = hesitation + quit
sometimes if I let off quickly, it would not quit. But if I pushed it, it would die. I could not re-start it until I added a gallon or so of fuel. As time went on, the 1/4 tank limit became close to 1/2 tank, and I got tired of constantly filling the tank.
When I removed the fuel pump, I found that the screen at the bottom of the bowl had dropped off, and the intake filter was filthy. Also, the insulation on the wiring was crumbling off. So, decided it was time for a new pump.
New pump was a new design with a revised bowl and the intake filter outside the bowl. It also has a new mounting design - it is attached directly to the cover plate rather than mounted to the bottom of the tank, so I had to remove the retaining ring from the tank bottom.
I think 99s were a different configuration, so not sure if any of this applies to you, but it does sound like a fuel pump issue. Hope this helps.
Kevin
