My 1993 940 Wagon sits at a train station for a week or more this winter, then takes longer and longer to start. After the first start it starts immediately in normal use, and runs fine. This last time I cranked until my battery got weak, then got a jump start, which also took a lot of cranking. No ignition at all until the end. Once there was one catch, others came, and the engine started, though sluggishly. But after that, perfectly normal. Any ideas? It hasn't even been very cold here (lower NY State). Rarely freezing in the daytime. In the 40's lately.