Tuff to Start

Just how cold are we talking?

The "later" smog carbs were very bad, but it should at least FIRE

My Grandfather used to start his 75 Dart slant, on about a 30 degree F day:

Floorboard throttle, this sets the choke

Crank engine, usually fires in about 3--8 seconds, "might run." Usually does

Put car in gear, might die, I'd guess about 20-30% of time. This is after 20? seconds of run time.

Floor throttle TWICE, as this pumps more fuel. Restart, cranks 2--8 seconds, and runs.

Let run (because now you say !DOH! for at least 1/2 minute

How old are the ignition parts, plug wires, cap / rotor? Plugs?

Has anyone checked cranking spark?

Does car set long periods, IE two weeks or more, with battery going low?

What shape is the engine? Mileage? burn oil? compression?

As with "the other thread" which is similar, check choke for freedom of movement, and check cold......................

Before cranking when it has been setting and is COLD, pull the air filter and watch the choke. Take your hand and smoothly floorboard throttle once and release. Choke should freely snap shut and throttle should return to "fast idle" cam.