I would hazard a guess that your 940S has the 2 Litre engine (B200). This is
normally fairly sluggish as it has to haul a rather heavy car around and is
not really man enough for the job. It sounds as if the inlet tract could do
with a thorough clean-up including the Idle Air Control Valve. The Positive
Crankcase ventilation system could also do with a refurbish. If you do not
have a turbo on your engine there is a filter included in the Flame Trap of
this system. This will need replacing as will the smaller of the two hoses
from it's top to the manifold, the nipple it attaches to will also need to
be scrupulously cleaned to ensure that there is no blockage occurring.

The sluggish when cold may well be due to a thermostat having failed open
and/or a non-functioning cold start injector.

Is your car a saloon or an estate?  If it is a saloon it is from 1992, 1993
or 1994. If it is an estate it could be from 1995.

Why don't you ask on the technical forum 900 series section of the Volvo
Owners Club website for technical help. We have a lot of knowledge available
to help Volvo owners in trouble.

Cheers, Peter.

One thought - may be a blockage in the catalytic converter. The effect is
something like the throttle not opening all the way.

I like the test Haynes has in the manual for my daughter's Honda (if you
have or can get your hands on a manifold pressure guage):
*connect the manifold pressure guage and note the reading at idle
*open the throttle by hand until the engine is running about 2000 rpm and
the guage has stabilized
*suddenly release the throttle and watch the guage.
If the exhaust isn't restricted, the guage should rapidly move back toward
the idle reading and should return to the original idle reading within two
seconds. If the guage hangs before dropping or if it gradually returns to
the original reading the exhaust is likely restricted - plugged catalytic or
muffler, something like that. The delay is caused by the engine being unable
to pump the manifold back down effectively against the back pressure.

Mike

Thanks to Peter and Michael for the great responses.  To answer Peter's
question, the car is a 1993 estate (station wagon).  I think the engine is
a 2.0 liter.

So, I've taken it in to have the cat cvtr looked at and they discovered
the mid-section and rear-box (muffler) needed replacing.  Had that done
but the car is still sluggish although it does seem do run a bit better.
But definitely bad on hills and quick acceleration.

I've discovered how to check the fault codes and found 121 and 231 off pin
2 and code 214 off pin 6.  I reset them, drove the car around the block and
checked the codes again.  231 was the only code to reappear.  I think it
means the petrol mixture is too high.

Any further ideas?

Oh, and Peter, what is the URL for the Volvo forum you sited?

Thanks a bunch,

David