Choke

It's a vacuum operated opener, so check to see if the vacuum diaphram is holding vacuum. You can either get a vacuum tester(hand held pump), or use a rubber tube and suck on it, if the opener is OK it will hold vacumm and the linkage will move, if no good it will leak, and linkage wont move.

Is there vacuum to the choke opener?
Is choke opener diaphragm leaking?

Or this could also be the concern.
COLD MIXTURE HEATER

All models are equipped with a cold mixture heater. When coolant temperature is low, the ECU
activates a heater in the intake manifold which warms the air/fuel mixture. This system promotes
starting in cold weather.

1. With choke valve fully opened, check to ensure that it closes completely when coil housing is rotated counterclockwise.
2. Position coil housing so that it will align with choke coil cover center mark. Choke valve will close fully when ambient temperature reached 77 degrees F (25 degrees C) on all except 3A-C, 4A-C and 4A-LC engines or 86 degrees F (30 degrees C) on 3A-C, 4A-C and 4A-LC engines. Also, each graduation on thermostat case equals approximately 9 degrees F (5 degrees C).

See diagram below for a breakdown of the components