Comments:
1. From your writeup I cannot be sure you are actually bleeding the filter head. If I'm wrong ignore this comment. Just pumping until the pump gets had without opening bleeder screw won't remove the air. Correct technique (I like to have a bit of vinyl tubing on the bleeder screw leading to a catch can/bottle as it keeps the mess down and lets you see when air bubbles stop) pump primer, crack bleeder, when fuel flow stops, close bleeder, repeat.
2. do you have a 1st gen fuel filter head (on 2 gen the 2 electric plugs are essentially the same size and the one on the right as viewed from the front has a blue cap)? If you have a 1st gen filter head get a 2n gen one and the wiring pigtail (ca. $125 with new filter and WIF sensor already installed).
3. check filter head for leaks (both electric plugs, WIF sensor on bottom, bleeder screw, primer pump shaft, both hoses and fittings) using a dry paper towel. If leaks found fix if possible or replace defective item.
4. did you recently change your fuel filter? If so did you accidentally leave the inner gasket on?
5. if none of the above consider:
a. an inline fuel pump either in the engine bay or ideally back near the tank as in
http://liberty.eurekaboy.com/kennedy.htm . A good relatively inexpensive inline pump is the Facet 40109 (4-7psi) or a maybe a pump from a 1995 or so 6.5 TDI Chevy Tahoe (NAPA part #AFP E3309 or Airtex E3309) pump. The Facet is available from
http://www.yachtsupplydepot.com/mechani ... t_697.html . Be sure to use marine grade diesel rated fuel hose not the cheap stuff.
b. consider dropping the tank and replacing the fuel supply line quick disconnect fittings with solid fuel hose. Absent filter head leaks these fittings are the most common source of air in the fuel line. IMHO the intank pump while a nice addition is not essential if these fittings are replaced.
PS while taping the quick disconnects might help I suspect that if you have enough access to try tape then you have enough access to cut out and replace with hose. I may be wrong but it's my understanding the fittings are on top of the tank.