On an overnight cold winter start before touching or pumping the gas, basically just removing the air cleaner before touching anything, should the primary air shutters be fully open or mostly closed ?

 

I guess you're talking about the choke?

If so, kinda depends on several things. Generally though, the choke will be open because the fast idle screw will be being held tight against the cam by the choke stat spring tension, which won't let the choke linkage move until the screw is lifted off of the cam by opening the throttle. At that point the linkage will become free to move and the choke will snap shut.

 

Yes, the choke. So just to be clear. If I were to take the air cleaner off on a cold winter morning the primary air shutters could be fully open until I activate the choke by pumping the gas to the floor and then the shutters should fully close, and when the car starts they will open slightly and slowly open fully as the car warms up ? Is it also true that the choke stat only controls the length of choke time ?

 

More or less, yes.

You don't necessarily need to "pump the gas to the floor" to allow the choke to close; only just enough to let the screw clear the steps of the fast idle cam. However, pumping to the floor will deliver the max available accelerator pump shot, which might help it start up quicker, depending on the ambient temp; and is the usual procedure. Except that the colder it is, the more it helps to pump it an extra time or 2.

The vacuum break diaphragm (front pass side of the carb) will crack the blade open a bit once the engine begins running, as long as it's working. It also provides timing for the secondary air valve, such that if it doesn't work, that can add to the legendary "bog" that Q-Jets are blamed for when stomping the gas to the floor. Seems odd that one part can have 2 such massively different functions, butt hay, that's the way it is. Look at the linkage, you'll see how it does it.

It also controls the spring tension on the choke blades. When they're closed, and you give the car the gas, more air tries to come into the bores, which it can't because of the choke; butt the blades are offset on their shaft, such that vacuum below them pulls them open. As the choke stat warms up from its electric heater, that tension decreases, thus reducing the richening effect that the choke has during that time. The choke stat is just that, a bi-metal thermostat; the electric power heats up a heater that's wrapped on as a 3rd layer on the bi-metal.

 

Once again, Thanks for the help.

 

I getting closer. High idle works great, choke stat works great but when I kick off the choke after 2-3 min sometimes it stalls an will idle ruff and hunts between 600-1000 rpm. To be sure its not a vacuum issue, I have replace all vacuum lines and as a second test I plugged all the ports except for the vacuum advance. Starving for gas ?? could it be the inline fuel filter at the tank ??