Audi A6 1996 , cut out on the way home, started,

Audi A6 1996 , cut out on the way home, started, and idles for a few seconds then chugs, if i floor the accelerator, car runs low revs, then cuts out. Discovered dirty fuel filter, replaced it, now it seems I cannot get car to start, loosed fuel filter to check for fuel, no fuel getting through, maybe an airlock, or has the fuel pump gone ? How do I solve Airlock problem ?