Stop in for a cup of coffee

Mattax said
and then make sure the flapper in the snorkel opens when the engine is running.
It's vacuum 'motor' that opens the valve. A thermostatic valve will know to close the flapper when the air termperature gets too warm.

And the big flippy flopper on the manifold. They tend to rust solid...

Mattax said
The vacuum hose diagram may be on a sticker under the hood. I don't know what year they started doing that.

Mine is on the inner fender