[buster73]

If the rust really comes from the fuel line and flushing won't help, you might indeed have to think about replacing the fuel line. Do you use your car on a regular base ? If it sits for long times, water might collect at the bottom of the tank and get into the lines.

To save your fuel pump in the meantime, you might add a small line filter just before the pump. Adding carb/injector cleaner to the gas should help to purge out loose particles.