Fw: '98 A6 2.8 won't start- mechanics are at a loss...

["JC.NEGRON" <elprofe@isla.net>]

HI GUYS ABOUT THIS PROBLEM YOU HAVE TO CHECK THREE THING'S...
HAVE GASOLINE?..RIGHT
HAVE AIR(COMPRESSION) RIGHT
HAVE SPARK..RIGHT
WELL IT IS NOT  ALL RIGHT, HOW ABOUT SENSOR G28 SPEED SENSOR SEND SIGNAL FOR
SPARK AND TIMING
AND BOTH HALL SENDER(ON BACK OF CYLINDER HEAD) AND GUESS WHAT..THE NEW
THROTTLE VALVE CONTROL MODULE. IF FOR SOME REASON HAVE A WRONG SIGNAL FORGET
TO START...THE GUY THAT IS PERFORMING THE DIAGNOSIS ON THIS VEHICLE HAVE TO
BE VERY SKILL WITH THE VAG 1551 SO I RECOMEND THAT YOU BETTER GO TO THE
DEALER..MAYBE IS A SMALL THING BUT IS DIFFICULT ON SITUATION LIKE THAT..
----- Original Message -----
From: Tom Nas <tnas@euronet.nl>
To: Bernard Littau <bernardl@acumenassociates.com>
Cc: <quattro@audifans.com>
Sent: Monday, August 16, 1999 1:48 PM
Subject: Re: '98 A6 2.8 won't start- mechanics are at a loss...


> "Bernard Littau" <bernardl@acumenassociates.com> wrote:
>
> >>Car stopped running a couple of weeks ago, just died on the highway.
It's
> >>been in the 'shop since.
> >>
> >>All systems check out, no fault codes. Fuel and spark verified, timing
belt
> >>OK and not jumped a tooth. When you start it, it turns very quickly as
if
> >>there's no compression (which is OK when tested, BTW). Not even an
attempt
> >>to start, nothing.
> >>
> >>My first impression: plugged exhaust/cat. Any other suggestions?
> >
> >I hope there is more to the story than what you wrote so far.
>
> Not a lot, but I'll answer the questions as you ask 'em.
> >
> >(Warning, Bernard the amateur home mechanic shooting off his mouth, but
here
> >goes...)
> >
> >Has a compression test been run?  What are the results?
>
> That I did write: compression's OK.
> >
> >Very weak spark could become no spark on compression, but still spark a
plug
> >when a plug is energized outside of the engine.  Have you tried an
inductive
> >timing light?
>
> Verified this with my friend- yes, they have.
> >
> >How is the air intake path?  Throttle body shut?  Obstruction?
>
> Nothing there. They've disassembled everything.
> >
> >The ECU make be bad, too.  No codes may be due to broken ECU.  Can you
swap
> >ECU?
>
> That was my first suggestion, too. He said systems checked out OK, ECU
> self-diagnostics were fine. There was no second car available for ECU
> swapping, but it could be arranged with the help of the importer.
> >
> >Cat plugged might do this, but I've never seem one be so plugged the car
> >won't start -- they usually go slowly.  Doesn't the 2.8 have multiple
cats?
>
> I think so, yes. No data for this offhand (ETKA doesn't run on my home
> system, I'll check it at work tomorrow).
> >
> >No fuel also a possibility, how was this verified?  Put some gas into the
> >intake manifold and try and start it.
>
> Fuel pressure measured at the injectors, checked out fine.
> >
> >Interesting problem.
>
> I'd say so... thanks for your suggestions so far!
>
> Tom
>
>
>