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

[Tom Nas <tnas@euronet.nl>]

"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