Replace the fuel pump.
I would try the fuel pump relay first. That could be bad. I wouldn't jump into changing the fuel pump right away like the first answer. Why do that when the problem could be a cheap relay!!! Also if you haven't changed your fuel filter in a long time, do so. This is a regular maintinance job just as changing an air filter or wires, oil, etc.
15.5 gallons
$25 or so
eBay has the best prices!!
25mpg hwy
replace the fuel sending unit in the gas tank.
fuel pump if mechanical
you have to drop the muffler and the gas tank. it is a pain, but easily done. in the fuel tank
50
Blown fuel pump fuse, defective fuel pump relay, or the fuel pump has failed and needs replacing.
At least 40 psi
VATS system
it is probably a bad ignition module or computer