91 Audi 100 Quits Intermittently

[njones <njones@afit.af.mil>]

I'm a newcomer to this discussion list, but I have a tough problem that
I could use some help on.

My 91 Audi 100 quits intermittently when driving.  There doesn't seem to
be much of a pattern to when it quits.  After driving the car for 30 to
60 minutes, the engine shuts off.  After the engine quits, the car will
crank, but it will not start.  After the car sits for 15 to 30 minutes,
it will start and run ok for another 30 to 60 minutes...  Of course,
when I try to duplicate the problem by letting the car idle for hours,
or even driving it around for a couple of hours, the problem doesn't
duplicate.

I have tried replacing the ignition coil, fuel filter, and fuel pump,
but the problem continues.

Please e-mail any suggestions to njones@afit.af.mil.  I would greatly
appreciate any help you can give me!

Nathan Jones
njones@afit.af.mil