[s-cars] 1995.5 S6 Running Real Rich, Flooding Under Boost

[chris chambers]

Scott,

I'd check and make sure it has the right spark plugs, plus I'd
be suspicious of the oxygen sensor as a bad oxygen sensor will
make it run rich.

HTH
Chris



--- On Fri, 2/6/09, Scott Houser <swhouser at gmail.com> wrote:

> From: Scott Houser <swhouser at gmail.com>
> Subject: [s-cars] 1995.5 S6 Running Real Rich, Flooding Under Boost
> To: s-car-list at audifans.com
> Date: Friday, February 6, 2009, 8:29 PM
> Hi,
> 
> First post. This one is perplexing me, and our indy
> mechanic {who's good.}
> Any suggestions appreciated.
> Car has 82K miles, and a lot of work has gone into it to
> make it right over
> the past year. Car has an IA Stage III+ chip {their term},
> Samco hoses w/Breeze CT clamps. New 034 MAF to Turbo Hose.
> {All mods are
> with 5K miles}
> 
> We had a couple of dying coils, and decided to go with an
> O34 HO coil kit
> after a lot of thought. After installation {a week ago}
> we had lots overboost. Found a tiny tear in the WG
> diaphragm and replaced
> it. That was after checking, and swapping with
> another car { one of our shop's tech's has an S4}
> the N75, the BPV, the ECU,
> the Fuel Pressure Regulator, and testing the coolant
> sensor, knock sensors,
> the MAF sensor, etc.  O2 sensor was new 5K miles ago. New
> Fuel pump and fuel
> filter, as well.
> 
> Right now the car will pull very smoothly, under load, to
> 6000rpm as long as
> you stay out of boost. With more than 5 psi, the car
> stumbles, and is held
> back. It floods, and is obviously dumping unburned fuel. A
> ton of black
> smoke. Very strong fuel smell. Pull the plugs and
> they're black with soot.
> We've pressure tested it to 20 lbs., and it holds for 5
> minutes {maybe
> drops 1 lb.}. The car's been smoked. No leaks show.
> Sure sounds like a boost
> leak.
> 
> I'm away on business, and won't get to the car
> until next week. It's at my
> mechanic's. He's real good and knows Audi fuel
> delivery systems inside and
> out. He's stumped, and so am I. I guess that the next
> step is to pull, and
> re-tighten all of the Samco's, to make sure. I would
> have guessed a blown MM
> hose, but that's not it. I have a metal crossover pipe
> on the way, but the
> plastic one looks fine. The intercooler tanks are OK, but
> I'm replacing with
> an aluminum S4 IC.
> 
> Any suggestions and ideas of what to look into much
> appreciated. As my tech
> says, "there has to be one tiny thing that I'm
> missing."  Thanks, very much.
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