It cuts the fuel while on a last quarter gage and use more fuel in few kilos

About one year ago my Passat would crank over but not start. Since then I’ve had the fuel filter, battery, crank sensor and additional warranty issues fixed. I’ve had it into specialized Volkswagen mechanics and the dealer ship in about 8 times total. No one can figure out why the car intermittently does not start because there is no fault reading. It has happened during warm and cold days, right after driving and when starting up the first of the day. And ideas would be greatly appreciated, thanks.
John

The car has no power, sometimes it runs great and sometimes it doesn't and sometimes it starts to run really well up to over 4000rpm and it seems to jerk... what's new: vacuum hoses, maf sensor, turbo, fuel pressure regulator, n75, lambda before the catalytic converter, fuel filter, spark plugs... I've been dealing with this for a year and I can't figure anything out