Interesting problem.  I don't have an answer but here are some
suggestions.  I would guess you either have a fuel problem or an
electrical problem and the problem is to identify which is the problem.
 (Does your car have an ordinary distributor with points or one of the
fancier electronic gadgets ... beyond my time I am afraid).

Similar experience from my 1979 900 GLE (injection non-turbo but I think
a different engine to your 1984 model).

It did not display any of the running problems you have, however, once
stopped the engine could refuse to restart when warm.  It also happened
once or twice with a cold engine.

1.  SAAB suggested at the time (I could not afford to pay them to solve
the problem) that the fuel injectors have had it.  It would be possible
to clean them or replace them, I could afford neither, so I was given a
bottle of some cleaning fluid (1 litre) that I added to a full fuel
tank.  That liquid was supposed to be used once in the lifetime of the
car.  It kind of worked.

When it would not start with a warm engine it was always fuel starvation
(ie. I removed the sparking plugs and they were dry).  Since then I have
come accross information which pointed to some sensor for warm starting
and something to do with fuel evaporation because of the heat of the
engine.  *If it means something I hope someone else can explain more.*

2. Once or twice it did not start in cold mornings, removing the
sparking plugs showed that the engine was flooded with fuel, hence I
suspect(ed) electrical problems.

Other similar(ish) experience from 1983 900 GL(?) twin carb non-turbo.

Eventually the coil went on that car (not sure if your car has a coil).
 Its effect was to make starting difficult and running weak.

=====================

I can't help with the problems you have when the car is running.  But
when it does not restart warm or cold remove a sparking plug and if it
is covered in fuel, you most likely have an electrical problem like weak
spark.  Else you have a fuel related problem.

There is my life story with SAABs.  Now I let the dealer clean me up ;-)

If it helps at all.
Charles

Check the distributor cap, I ran across a similar problem on a '79 Volvo,
the spring loaded center contact had broken so it was arcing intermittantly,
took a while to track down. Also check the pickup in the distributor, I've
seen those get a broken wire which makes and breaks contact as the vacuum
advance mechanism moves.

Well it does sound like the air mass meter to me problem is you dont have
one.  I would change the dis cap it is cheap enough and also you did not
mention plugs were they checked im sure they were.  Is your check engine
light on saab service can run the codes and find your problem im sure
anyway good luck papa

It does sound like a combination of dampness and ignition. You didn't say
explicitly, but I suspect it to be that little bit after about 5 minutes of
starting from cold when the engine starts to shut off parts of the cold
start system, but before the car is fully warmed up. Dampness will
exacerbate the problem.

I see we can discount a clogged fuel filter as the problem, since that has
been replaced. I would begin with replacing the other cheap bits, too, such
as spark plugs (only use NGK and BP6ES should be right for your car), air
filter, rotor arm and distributor cap. A Bosch arm and a Lucas cap are my
preferred parts, but they're not as touchy as spark plugs if you use a more
generic brand. Perhaps the ignition coil, too, although that is unlikely.

Which part of the cold start unit was replaced? The thermo-time switch is
the usual culprit when cold starting is difficult. That should be located
between the intake runners on top of the block between cylinders 2 & 3.
That's the bit that controls the whole cold start system. With the car cold,
remove the plug and connect a test lamp in series. The lamp should light. If
not, you've got a wiring problem or the switch is broken.

Test the cold start injector by removing the plug and connecting a
multimeter. You will get voltage when cranking the car.

Likewise, the warm-up regulator (the unit with two fuel lines near the
thermostat) can be checked by removing the fuel pump relay and bridging
terminals 30 & 87. Quickly check for voltage, which should be at least
11.5V.

If the idle drops very low during this problematic period (which I suspect
it does), the auxiliary air valve is likely to be the problem. This unit
supplies more air into the system during warm-up. If it's broken, you'll be
experiencing a very rich mixture during warm-up. Again, with a cold car,
remove the fuel pump relay and bridge terminals 30 & 87. Switch the ignition
on and look through the valve. It should be open when cold and close after
about 5 minutes by the thermo-time switch. While you're there, remove the
unit from the car and clean it through with carburettor cleaner and then a
little lubricating oil, like WD-40.

Good luck,

Paul

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