Engine cut-out - still

[Robert Myers]

Hi Y'all,

Well, I'm totally bumfozzled.

A few months ago my '95.5 S6 (RS2ed) was suffering (no make that "I 
was suffering") a frequent engine cut-out.  I'd drive along at more 
or less constant throttle setting and the engine would just buck as 
if the ignition were turned off and then back on quickly.  At that 
time I got a lot of really good suggestions from several listers and 
I really appreciated the suggestions.  The cut-out grew progressively 
"worser and worser".  The cut-out became more and more frequent and 
lasted longer and longer before the engine would again 
restart.  Finally, when the day came that the engine simply would not 
fire, I loaded the bitch onto a flatbed and had her taken to my local 
stealer.  The old-time certified wrench there spent three weeks 
determining that he could not find the problem.  :-(  The car started 
and ran perfectly for him.  He did find that it did cut out on him 
once and he found that the injectors were not providing fuel at that 
time.  Following that incident it never again misbehaved.  I finally 
brought the car home and it ran perfectly for me for several 300+ 
mile trips over several weeks.  Yesterday it started misbehaving 
again.  I'm beside myself.  It's enough to make me start 
reconsidering Audis.  Hmmm...  Evo?  WRX?

Items checked (from memory so I may be omitting something):

No codes stored
ECU and chips (swapped with known good - no change)
Ignition system (swapped 1.8t conversion w/ OEM - no change)
Fuel pump (replaced twice - first replacement was also defective)
FPR (replaced)
Fuel filter (replaced)
Spark plugs (replaced)
Ignition switch (replaced)
CPS (replaced)
WGFV (replaced)
BPV (replaced)
Exhaust system (blocked kitty - system is now Stromung w/ test pipe)
Engine speed sensor (swapped between cars - no help)
Probably a dozen other items checked/replaced early on and not listed 
here from the effects of advancing Alzheimer's.  :-(

Suggestions?  At this point an "accidental" fuel spell and a spark is 
beginning to have some appeal.  ;-)