Your injectors may need a good cleaning too. If the fuel isn't atomizing properly, it'll have a real tough time firing at those low temps. Have you ever cleaned/had them cleaned?

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250