Issue 1 - new or rebuilt carburetor?

Issue 2 - if you replaced the vacuum advance, and it still does not move, did you check to see if the plates in the distributor move? If not, definitely a problem.

Issue 3 - political problem (garbage gas).

http://www.thecarburetorshop.com/Troubleshooting.htm#Hardstartcold

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop