Cold weather stalling/rough idle

[jwatkins]

My 1988 325is has a stalling problem that only shows up when it's been left out on very cold nights. It starts and idles normally, but when I go to drive it, it will occassionally stall and shudder violently. It never quits completely, and the problem persists, even after it has warmed up. The last two time this occurred, the car had been sitting out for several days, and the outside temperatures were in the mid 30's. I suspect water contaminating the fuel system and freezing in cold temperatures, causing a blockage.
Also, when the car is idling, it has an intermittent rumble or miss. The idle is fairly steady, but there can be a slight drop when this rumble is heard. Probably related to the problem above. Any advice would be greatly appreciated. Thanks.
Jeff Watkins

[Jared at Pelican Parts]

try changin out the fuel filter.

also look at this thread..

Hunting Idle--Stalls

[BANANA MAN]

a few things to try. clean off your crank sensor, their magnetic and dirty quick i think its right on the front of your engine should unbolt with a hex key. if that doesnt work unplug your idle control valve shoot some carb cleaner in there and plug it back in get all the gunk out of there. if that doesnt work pop off he back seat and rip out the pump . . . . i have never seen a filter clog up to where their was a variable that was that sensitive to temperature. My dad just had this problem with his 325 convertible 88 and it was the pump. we started diagnosing at the cracnk sensor, then the idel control valve, then the pump. The only thing that really allowed us to do that thoug hwas the fact that we had an extra pump . . . i dont know there are some options.