Replaced the head on my '87 5ktqw, ran 5.6 miles now won't run.

[Rod Michaelson <HOTROD@pacbell.net>]

Well so much for figuring out my Audi. It has won again!
After replacing the head gasket, having the head reworked, replacing all 
the vaccumm hoses, new timing belt, plugs, ect. I ran it three times 
locally to make sure all was well. 
   The first two times it ran great, better than ever. Last time got 3 
miles from home, was resetting the trip computer MPG and the motor quit.
Turns over fine but in a second or two the engine dies like it is getting 
no fuel (just running on burst to cold start solenoid) . I checked the 
codes by using fuse in fuel relay and got 4444, then solid light next 
time, and no light the third time. 
Replaced the fuel relay, still nothing. Had the wagon towed to my 
mechanic and at first thought it was the fuel pump. The pump is fine.
He is not sure where next to look.
What now? Any suggestions.
Rod Michaelson
Walnut Creek, CA
p.s. have the Bentley repair manual to use.