[V8] Hello (again), and maybe some advice?

[urq]

I've heard access to the panel the sensors is on is difficult, but I believe
it is characteristic of the automatic version.  I've never had any
difficulty accessing the panel on the 5-speed.  

I'm surprised that you hadn't heard of this one before ... the flywheel
sensors are the Achilles' heel of the V8Q.  The sensors are very similar to
those used on other Audis, which don't seem to have as big a problem with
failure.  Even though they are behind a heat shield, the heat from the
exhaust must stress the sensors.  The ECU needs the signal from the sensor
to know when to fire the injectors and ignition coils, so it would explain
your symptoms.

I usually pull the driver's side front wheel, but I don't know that is
mandatory.  If I want to get at the connectors from above I pull the snorkel
on that side, and that's it.  More often than not I reach up from underneath
... 

The mounting plate is held in place by the same bolts that attach the heat
shield, 8mm socket + 1/4" drive ratchet.  

For me the problem usually starts as an intermittent one, usually associated
with heat ... the car will start again after it cools down.  Eventually it
becomes a hard failure.  It looks like you may have skipped the intermittent
step ... not so sure I'd claim a design issue with parts that last 10+ years
and 150K miles though ... 

Steve Buchholz

-----Original Message-----

Thanks for the help.  I'm not familiar with this problem.  It creates this
condition - sudden loss of spark and fuel?

Is it usually preceded by any symptoms?  Or it just goes and that is that?
I inquired at a newer forum - I think AudiWorld, and had the same
suggestions from a V8 owner in NJ (maybe he's on here, too).

Which pins do I check resistance on to verify - the ones under the
distributor (grr... I do know how hard it is to get down there).  Boy, that
sounds like a fun Saturday project.

Bryan



On Fri, Jan 8, 2010 at 7:33 PM, Tony and Lillie <
tonyandlillie1 at earthlink.net> wrote:

> Bryan,
> First of all, congrats on keeping the car. Toyota or V8, that's not even a
> hard decision for me, and I'm not the V8's biggest fan ;-)
>
> Onto the fix:
> Sounds a lot like the classic RPM/Reference sensors going bad. They are
> located below the drivers side exhaust manifold. A bit hard to get to, but
> nothing impossible. However, the connectors for them are below the drivers
> side distributor, and they are not fun at all to get to. I usually pull
both
> the coil and distributor when I have to mess with them. You can ohm them
out
> if needed, should be around 1000 ohms across two of the three pins. I
> believe they are the two outer pins, but it's been a while................
>
> BTW, las ttime I checked, 5000TQ sensors were the cheapest, and
> electrically identical. The wires a re a bit longer, but they can be wire
> tied out of the way easily.
>
> HTH,
> Tony
> ----- Original Message ----- Subject: [V8] Hello (again), and maybe some
> advice?
>
>
>
>> And of course, as soon as I decide that, it dies on me in a mysterious
>> way!
>> So I'm also looking for advice.  It won't start, and I appear to have no
>> fuel or spark, but plenty of crank.  The car was last driven on a short
>> hop
>> about 3 weeks ago.  A little hard to start (had been sitting a while) but
>> it
>> ran fine.
>>
>> 1) Pulled plugs, can't smell fuel after cranking and there is no spark
>> when
>> cranking.  Do not hear fuel pump when cranking.
>> 2) All fuses OK.  Pulled fp relay, jumped it, and fp whines away audibly.
>> When cranking in this mode, still no fuel or spark.
>> 3) with key on, I pulled each coil connection (the three-bladed
>> connector).
>> One blade on each coil had power with key "on."
>>
>> What could fail and take away spark and fuel at the same time?  Any
>> suggestions for further diagnosis?  I'm decent with motorcycles and older
>> cars, but the various sensors and control components of modern cars is
not
>> something I'm "up" on.
>>
>
>
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