carburetor issue

hello all, i recently bought a new (remanufactured) carb on ebay for my fairmont. i replaced it cuz the fast idle cam, along with the stud that holds it on, had fallen off the old one and disappeared.

with this new carburetor, in the morning time, after the engine has sat for 12+ hours in the freezing cold, it doesnt fire up nearly as quick as it used to. before it would crank for maybe 2-3 seconds then fire up. with this new carburetor you have to crank it for literally 10-15 seconds before it turns over. ive got the air/fuel adjusted as good as i can get it, from listening and feeling how it drives, i dont have any tools for that. The fast idle and normal idle are adjusted to my liking, once the engine is running.

before i would just get in the car, pump the gas once, then hold it at half throttle and start it, i do that now this happens...

any input would be most appreciated....

The choke may not be fully closing. Take the screws loose from the automatic chock heated housing. When the engine is cold, rotate the choke housing until the choke fuly closes. Once the engine starts the vacuum operated choke pull off should be adjusted to pull the choke off about 1/8 of an inch .

And if the choke is working okay, the problem could also be the fuel is leaking out of the float bowl. This can happen if a gasket or an O-ring has shriveled from age. On some carbs the base gasket (the one in contact with the manifold) forms the bottom of fluid passages within the carb. A bad base gasket could therefore let fuel escape - or air get in where it shouldnt.
I have 2 cars that I really like (87 Dodge Omni 4 dr hatchbacks) that start just fine if used every day. But if they sit longer it would take a LOT of cranking before they started. But if I dribble fuel into the float bowl; then they start immediately. Both have carbs in them that were 'rebuilts' on ebay. But they had been rebuilt many years before, & the seller finally got tired of having them in his inventory and put them up on ebay.

I have also changed a couple of cars whose carbs had automatic chokes to have a manual choke cable. This is because the spiral bimetallic spring inside the auto choke 'ages' and doesnt swing properly over a wide range of temperatures. Since new cars dont use carbs anymore, its not likely replacement spiral springs will be available, like they were 20 years ago.