odd autox behavior/stalling

[Nathan Engelbert]

Autocrossed the 89 90q for the first time this season up in milwaukee
yesterday.  Other cars to note there were a 86-87 4kcsq and a 91 200q20v.
My car was set up beautifully, almost neutral handling.  I had some great 4
wheel drifts.

So,  the course was set up to be high speed, and I realized that while
hearing the engine wail at between 6500-7000 rpm in several sections in
second.  Not enough time to get into third.  Going into the first slalom on
one of my runs, I hit what I presume is fuel cutoff as the car dropped down
to about 5500 before it was willing to accelerate again.  It didn't
sound/seem the same as the rev limiters in the other cars that just keep
pushing the engine to redline and dropping off until just under.  I chalked
that up as experience and tried to keep under 6800.

BUT, on my last run, while shifting into second on the first turn, my car
just stalled going around the turn.  I had 3/4 of a tank of gas at the time.
I rolled to a stop and tried to restart, engine cranked, but no fire.  I was
pushed off the course, we listened for the fuel pump and checked for spark,
all were there, just no start.  After about 2 minutes of sitting and
monkeying around with checking for spark etc. the car started as usual, and
ran fine for the drive home.

Saturday I changed oil (mobil 1 15w-50 new oem filter) and replaced the air
filter.  In the past two weeks I have replaced spark plugs, cap, and rotor.
The fuel pump was replaced under 2 months ago with the blau pierburg unit
(making a 400-500 Hz tone while running, normal?), at the same time, fuel
filter was replaced as well.  The car pulled well to just under redline on
highway and track sunday.  I just can't figure out what could have caused
the stall/no restart.  The car had been running for about 3 minutes from
almost cold start when it stalled.  One of the suggestions was that oil/crap
could have blown back through the throttle body onto the air plate in the
MAF and caused sticky/odd operation.

Any other ideas, BTDT, etc. of what to do first that will keep this from
happening at the chicago region autocross this coming weekend?

TIA,

Nathan Engelbert
89 90q