'98 Concorde won't start / dies while driving

I have a 1998 Chrysler Concorde LX, 2.7l, with under 88,000 miles. My wife
drives it 90% of the time and she keeps telling me of problems starting and
dying while driving. I have experienced it several times myself, or I
wouldn't believe her. It seems to die more when under 1/4 tank of fuel, but
has a hard time starting at various fuel levels, temperatures (ambient and
engine), and when restarting after it dies. Many times after it dies, it
will kick and buck upon restart. Sometimes it will die when driving at any
speed, and other times when stopping. I have taken it to numerous mechanics
who can find nothing wrong. The plugs and pcv valve have been replaced. I
replaced the auto shutoff and fuel pump relays which seemed to help for about
3 months, then it started again. Also, it has been using alot of oil (4-5
quarts every 3k miles), but no sludge buildup, as it is burning it. Please
help!