I encountered this a short time after buying my '89 740 in January (of '94). The dealer service manager (also a mechanic, who actually wore work clothes) advised that -18C was the point at which these cars will have trouble starting. His solution? Depress the accelerator (yes, on a fuel-injected car!) about one-quarter of the way down, and hold it there. Crank the engine. When it fires, hold the pedal steady until the engine is running smoothly. Ignore the roar - it won't blow up, because it's not under load. It's worked every time for me.

The problem seems to be the cold start injector. Seven seconds of an enriched mixture doesn't seem to be enough below -18 or -20 Celsius. I've always found this a bit strange, given that these cars are from Sweden. On the other hand, maybe Volvo has always counted on people in cold climates using block heaters. I understand that Sweden actually has public parking facilities with electrical outlets for this purpose.