B5 S4 No start

[Mark R]

Thought I'd throw it out there to see if anyone has any BTDT on the modern
Audis.

This car has a shady history- front end wreck, purchased by local kid and
his dad to fix up, recently sold to another local (this one in college).
Car definately has aftermarket turbos, downpipes, Hatachi MAF conversion
(AWE), etc.  Only prior experience I have with the car is clearing codes
(random misfires) and CEL (repair of MAF wiring splice, then clearing
codes).

Just prior to being sold to current owner, car was run out of gas.

New owner drives car in for tires at a local tire place, several hours
later, it won't start.  Cranks well, no start.  I tow car to my place, add
fuel (approx. 2 gallons, as 1/8 tank showing), change fuel filter (I hate
where they put them on the Quattros, but that's ANOTHER tirade).  Still no
start.

Cranks well, added a battery booster (even though battery was topped off),
but no start,  Shows no codes (this is what surprises me).  Fuses in fuse
panel check OK.

I pulled ECU overnight, reset the batt. disconnected code.  No start.  I
have a stock ECU from my own S4 I tried as well (same P/N, one month apart
in production).  Same results.

Noticeable is that MAF g/s show as "0" while cranking.  IDK if this is
"normal" or not.  I don't think I've ever cranked a newer Audi more than a
few seconds.

So I have to do the "back to basics" approach (spark, fuel, air) to
diagnose, but I suspect I'll find some faulty wiring (since the car has
shady history and major work done in the past).

Any BTDT?  Good ideas?  What gets me is no codes at all.

Thanks!
Mark Rosenkrantz