I know this is not a 940 but I am not getting anything useful on the 200 side, so may be you gentlemen will indulge me here. The patient is a 1993 240 wagon, B230, manual transmission, 130k miles.

Fires up and starts immediately but then idle fluctuates to the point of almost dying, then kind of recovers for a second or two, then engine eventually stalls unless you keep foot on gas, and even then idle is lumpy and acts like it will die. This goes on for about 15 minutes getting progressively better until gradually it runs fine once warm. Problem started after the car sat unused for a couple of months. I have cleaned the throttle body and the Idle Control Valve, checked vacuum hoses, but it has made no difference. Ideas?

I think I got it resolved. Seems like this rough start condition happens after sitting. I went over tune up items, gapped the plugs, etc, and it seems OK now when started on a daily basis. Still has old gas in it, probably about 1 1/2 year old, so I expect even better performance with fresher fuel.

I never had similar problems with any of the 5 740s that we owned, except when we tried to sell our 744 TI - we were not driving it much.

My friend at my dealer told me to examine inside all connectors, clean them as much as I could, fill them with dielectric grease and zip tie them together if possible. He even gave me a small tube of the grease.

I did one connector each week so if I had problems, I knew where the problem might be. The problems went away.

My theory is this - When a car is run and driven, the connectors and wires get moved around a tiny bit, and this motion causes the connections to fret and keep them in good condition.

The more I drive my '64 544, the better it runs.

Did you read the FAQ?

I have a 1991 940 with a B200F, so not the same as yours, but similar.
You will have thought of this - but do you have an OBD reader under the bonnet?
My 940 has and it has solved several problems for me,

OwenF

Problem started after the car sat unused for a couple of months. I have cleaned the throttle body and the Idle Control Valve, checked vacuum hoses, but it has made no difference. Ideas?

-->You still have the old gas and many things deteriorate in a car sitting unused for too long. Check all fluids, top them up, then drive out, refill with fresh gas, refill the tyres, do some highway driving plus some Italian tune up when engine fully warmed (i.e 2nd gear at 50-60mph for few minutes ONLY) and car should be ok.

If you want to be more through, roll those ceramic fuses, unplug/plug those connectors in engine (plug cables, distributor, fuel injectors, AFM, relays, ignition module, battery posts, idle valve, TPS and so on) so that they all have fresh contacts. Those electrical contacts are self-cleaning. Cleaning agent not needed unless you really see some corrosion.

Even my 1994 940 left sitting for a week while I'm on overseas holiday started up with some lumpy idle and noisy belts.

Amarin.