Fw: No Start - 1987 5000CD Quattro Avant

[Doyt W. Echelberger]

I admit not knowing what is causing your described problem. If I were you,
I'd probably take it to my trusted independent Audi mechanic. I suspect a
fuel system problem, and the possibility of electrical problems as well as
vacuum leaks. And maybe a few more things.

I will relate my experience with a 1987 5000 turbo quattro. You may want to
check a few things yourself, before going to your mechanic.

Severe/alarming stalling and loss of power were the symptoms of a failing
oxygen sensor. Replacing the sensor solved the problem. The failing sensor
did not show up on a code dump. And it made the mixture run too rich.

Beyond the oxygen sensor, if I had your car, I'd do some general things
that might fix or reveal the problem source....or not. Finding and
repairing the vacuum leaks is a great place to start. I'd also look at and
feel all the walls of the crankcase ventilation hose, right up to the ISV
and beyond. And I'd review when the air cleaner was replaced, maybe even
look at it. And I'd carefully examine the catalytic converter and try to
determine if it had been hit, and perhaps damaged.

In addition to that, If I had the time and a place to work, I would locate
(using Bentley) all the electrical screw-down/bolt-down connection points,
and then clean those connections with steel wool or an electric drill wire
brush. You might find a broken or suspiciously flexible wire as you
carefully inspect these connections. The sensors work by sending signals
through wires. Wires flex and break, and connections corrode and increase
their resistance, sending faulty voltages to the ECU. I'd look real close
at the connections on the throttle switch. I might even replace that switch
if it is the original one.

Following the "wire theme," I'd  gently pull all the ignition wires from
all the sockets on the coil and the distributor cap, and I'd look for
corroded/wet/green connections and loose fits in the sockets. The coil
wires partially pulled out and the spark must jump a gap when that happens,
and the engine can run erratically. This is fairly common. I'd also check
the inside of the dizzy for cracks, dirt, and electrical discharge tracks,
as well as burned and blackened places on the rotor and the cap. I'd also
probably replace the ignition wires and the spark plugs.

That is where I'd start, if I had the time.

Doyt Echelberger
87 5ktq  240k miles





 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
At 06:51 AM 4/2/2002 -0500, you wrote:
>Thanks for all your help people.
>
>My problems, explained below, are due to a vacuum leak.  I found a couple of
>leaks and can now get the car started although it is not running well.  I
>will keep at it.
>
>Dave
>
>----- Original Message -----
>From: "Dave Marshall" <autolit at bmts.com>
>To: <quattro at audifans.com>
>Sent: Saturday, March 30, 2002 8:07 AM
>Subject: No Start - 1987 5000CD Quattro Avant
>
>
> > 1987 Audi 5000CD Quattro Avant - 326,000 km
> > Ontario, Canada
> >
> > I have searched through the archives and some excellent websites, but I
> > cannot find any talk of my symptoms.
> >
> > A few weeks back, I started having syptoms of trouble on it's way.
> >
> > Before the car was fully warmed up, it would stall at the first stop sign.
> > Initially it would start right up again and be OK for the day.
> >
> > Then the next step was that when it did this stalling it would not start
> > right up.  It seemed like I was getting a bit of fuel, enough to make the
> > engine fire a bit, but would just quit on me when I touched the gas pedal.
> > I would have to sit there, in traffic, wait a few minutes, try to start,
>no
> > go, wait, try again and eventually the engine would fire and run perfectly
> > all day.  It gave me the impression that a "sensor" of some kind was not
> > getting the input it wanted and was not doing it's job.  Suddenly it would
> > see what it wanted and way we go.  Pulling codes gave me no faults.
> >
> > This was intermittent.  I could go for days with no problems.
> >
> > Then one inconvenient Noon hour, I just couldn't get it to fire.  Same old
> > story of the engine wanting to fire, but there must be this daxx sensor
>not
> > getting it's information.  Left the car in the snow storm and came back
>next
> > day.  Hard to start, but once again, suddenly she fired and ran like there
> > had never been any problem.  No fault codes.
> >
> > Ran good for a couple of days.  Then suddenly no go.
> >
> > The last time I had trouble, I did the sit, wait, try again thing and
> > finally got it to run, but this time I had to keep the RPM's over 2000
>(3000
> > was better) or it would quit on me.  I tried this while running down the
> > road so I could bump start it when it quit.  Lots of fun driving through
>the
> > City this way.  :>)
> >
> > Now I can't get it to start at all.  I am sure that if I could try bump
> > starting, it would run, but only at high RPM's.
> >
> > I tried pulling codes.  OK - 4444 every time.
> >
> > I can hear the fuel pump running, building pressure and shut off.  I have
> > tried the fuse in the top of the fuel pump relay to make the pump stay on.
> > I have checked the fuel filter and can blow through it easily.
> >
> > The spark plugs are bone dry.  If I drop some fuel in the intake, the
>engine
> > will fire and run this fuel through before quitting.
> >
> > I don't know where to go next.  I mentioned reading the archives.  Lots of
> > talk about the engine misfiring at high RPM's and that most likely being a
> > fuel pump problem, but high RPM is when my engine works best.
> >
> > Anybody been down this road before me?  I would appreciate your help.
> >
> > Thanks
> >
> > Dave Marshall
> >