2001 Audi A4, 1.8 Quattro W/Turbo

if your selling it just say as is and figure it out :P. But this sounds like a fuel related issue. You likely just need a new fuel pump or fuel regulator. Its possible the fuel filter is clogged as well. To check the fuel pump simply turn the key to the on position and listen for the pump buzzing sound(easier done with back seat folded down) no sound means a pump. Fuel filter you can preaty much just rinse it out and throw it back on unless its really bad then with corrosion or filled full of gunk. (rinse it with gas not water) The fuel pressure regulator is often under the hood it is ussaly best to jsut have the fuel pressure checked before replacing but its a rather inexpensive part. I am willing to bet the pump died. Hope this helps.