[s-cars] 1995.5 S6 now running rough after warm up

[Jeff Postupack]

I installed a fuel pressure gauge during debug and I see
about 60 PSI idling, and when I open the throttle, it momentarily drops to
~ 55psi, then builds to 70 psi..
this seems pretty abnormal. Don't ever remember seeing this variation on
the Pearl S4

Frankly I'm just looking for the push and confirmation to JFDI.

fuel pump that is.. Just Freakin Do It.


On Sun, Jan 19, 2014 at 9:44 AM, Jeff Postupack <jeff.postupack at gmail.com>wrote:

> Gents.
>
> My old trusty winter  Blk/Blk S6 is now suffering in the barn.  157K miles
> Stage 1, stock all else
>
> I do try to keep up on preventative maintenance, but I may have
> procrastinated too long on one particular item.
>
> After a near flawless 720 run NH to PA- NH last weekend, it developed a
> misfire under boost around Jan 14th  It got worse and worse, until it was
> easy to debug on Thursday.
>
> I isolated that pb to a single Bosch spark plug, however I changed them
> all to new NGK BK7RE. being suspicious (The Bosch I removed were the
> tri-electrode, forgot the P/N)
>
> After plug swap it ran strong up until Sat morning.. when it started
> running so rough that I would not drive it up my hilly driveway, back in
> the barh she goes.
> (Sat am cold start, after warm-up rough idle and very low power,
> stumblinjg)
>
> Code is
>  00537 VAG1551/2 Fault Code Number- See below C/O QW
>
> After checking my records, I changed the easy stuff this morn.
> new fuel filter
> new Fuel regulator
> New Oxygen sensor.
>
> After each component change I cleared codes and ran again.
> 00537 re-activates.
>
>
> This brings me to the last one you guys may say is obvious, Fuel Pump.
> I don't have records on this being changed..Hard to believe but..
>
>
> QshipQ? , Dave Dawson? All takers?
>
> Go ahead, beat me up for not changing the FP, but HELL! It's January in NH!
>
>
> Jeff Posto
>
> Oxygen Sensor Control Limit exceeded,
> fuel pressure too low or too high,
>  intake or exhaust leak,
>  defective ignition system component,
>  intake air leak after air mass sensor,
> O2 sensor is faulty
>
> Symptom: CO before catalyst is below 0.3% or greater than 1.0%, Extremely
> lean or overly rich exhaust, Spark Plug foulin
>