[s-cars] Please Help - Car bucking under WOT

[Scott Munger]

While the image of a bucking car is humorous, I'm not laughing :-(

My wife and I took the S car to Vegas yesterday.  We live in Flagstaff (7300
ft, 42 degrees))... after about 2 hours on the interstate under moderate,
with stints to max (80-120mph), boost we come into Kingman (< 4000ft 68
degrees) for a pit stop (I ran minimal boost and light footed for about 5
minutes before pulling into a stop), turn off the car, bathroom break, back
into the car and start it up.   Heading up a fairly steep grade in 4th, I
get excited about the sound of the turbo on the concrete dividing wall and
ask my wife to "listen to this"... I depress to WOT and the turbo spins,
wooshes, then the car horribly thrashes as if I've stalled the car and
tapped the brakes (heavily).   It feels like the engine is being cut off
abrubtly by the ECU in response to boost... but I've no idea.  I test it a
few more times and can repeat the behavior.  Ugh, I'm sorely disappointed
:-(  The car seems to be running well other than when at heavy throttle.

I gingerly drive the remaining 100 miles with no problems, yet never get on
the accelerator (no need to be stranded in the desert).  On the return trip,
today, I test the same procedure to no avail, although it seems like boost
isn't kicking in that much... the car feels much slower at WOT.  The whole
trip home I drove with a reasonable degree of light footed ness, then once I
was closer to home, tried to reproduce the problem... no problems, yet boost
still isn't kickin' me in the butt.


Any insight into this problem is greatly appreciated.  Is it an electrical
cutout by the ECU?  Perhaps detonation and subsequent adaptation by the ECU?
I've never had a problem like this.

--Scott Munger
'93 S4