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

[Joshua van Tol]

Have you checked for a torn diaphragm in the fuel pressure regulator?  
Usually that would be worse at idle/high vacuum conditions, but who  
knows?


On Feb 6, 2009, at 9:06 PM, swhouser at gmail.com wrote:

> Thanks, Chris.
>
> Bear with me as I haven't been near the car for the week (I know  
> that sounds crazy....but this has been driving me crazy!)
>
> I know that the MAF sensor was swapped with no change, but I'll  
> clean and check the connectors to make sure we're OK there(if he  
> didn't do it) My tech had pretty much ruled out the MAF, but we'll  
> double check.
> What I'm trying to "connect" is why this would have happened as the  
> new coil kit went in, and as a new MAF to Turbo hose was  
> installed.  Seems to have perhaps opened up the diaphragm tear in  
> the WG, and now this. Wierd.
>
> Thanks for the ideas. I'll look into any and all.
>
> Scott
>
> Sent from my Verizon Wireless BlackBerry
>
> -----Original Message-----
> From: chris chambers <fastscirocco_2000 at yahoo.com>
>
> Date: Fri, 6 Feb 2009 18:55:24
> To: <swhouser at gmail.com>; Scar<s-car-list at audifans.com>
> Subject: Re: [s-cars] 1995.5 S6 Running Real Rich, Flooding Under  
> Boost
>
>
>
> Scott,
>
> a bad MAF or dirty contacts on the MAF/MAF cable can cause
> the ECU to think it's in an overboost situation, normally when
> this happens it shuts off the fuel to stop the overboost.
>
> I had this happen to my car, felt like I hit a wall cause the engine
> basicly shuts off momentarily due to the shut off of fuel. If I drove
> with no boost it ran fine up to redline, but if I accelerated hard
> it "bucked" at ~ 4k rpm.
>
> So I'm wondering if the same problem could fool the ECU into thinking
> there is more boost than there actually is (but not overboost) and  
> supply
> more fuel for the boost it "thinks" is there.
>
> You might want to take some contact cleaner to your MAF sensor's  
> connector,
> and to the MAF cable's connector. If you have another MAF sensor  
> you might
> want to swap it in, but make sure the cable/s connector is clean  
> and not
> corroded.
>
> HTH
> Chris
>
>
>
>
> --- On Fri, 2/6/09, swhouser at gmail.com <swhouser at gmail.com> wrote:
>
>> From: swhouser at gmail.com <swhouser at gmail.com>
>> Subject: Re: [s-cars] 1995.5 S6 Running Real Rich, Flooding Under  
>> Boost
>> To: fastscirocco_2000 at yahoo.com, "Audifans" <s-car-list at audifans.com>
>> Date: Friday, February 6, 2009, 9:41 PM
>> Thanks, Chris.
>>
>> Plugs are F5DPOR's.....they were almost new and I just
>> replaced them with a second set to be sure. Think we're
>> OK there.
>>
>> O2 sensor is almost new. Think that could fail in about 6K
>> of driving....a year? Maybe we'll swap that out
>> And see. Lee has probably tried that already.
>>
>> Runs very smoothly out of boost, even under load.
>>
>> Thanks.
>> Sent from my Verizon Wireless BlackBerry
>>
>> -----Original Message-----
>> From: chris chambers <fastscirocco_2000 at yahoo.com>
>>
>> Date: Fri, 6 Feb 2009 18:24:50
>> To: <s-car-list at audifans.com>; Scott
>> Houser<swhouser at gmail.com>
>> Subject: Re: [s-cars] 1995.5 S6 Running Real Rich, Flooding
>> Under Boost
>>
>>
>>
>> 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.
>>> _______________________________________________
>>> S-CAR-List mailing list
>>> S-CAR-List at audifans.com
>>> http://www.audifans.com/mailman/listinfo/s-car-list
>
>
>
> _______________________________________________
> S-CAR-List mailing list
> S-CAR-List at audifans.com
> http://www.audifans.com/mailman/listinfo/s-car-list