There is a one way valve on the fuel pump which is supposed to prevent fuel from flowing back into the tank and therefore losing line pressure. Its the little nipple assembly screwed onto the fuel pump which is the outflow, pressurizied side. Could be gummed up or maybe the internal spring has failed.

There isnt a choke but the air slide valve functions that way. Its on the side of the block up front and has two hoses to it. One gois to the air filter box the other to the throttle body. When the engine is cold, its supposed to be open so lots of air flows along with lots of gas for a rich mixture. As the car warms up, it closes down and then air flows through the idle adjust assembly which is connected across both hoses a few inches down the line from the air slide and has the large plastic idle adjust screw on it. Maybe the air slide is gummed up. If you take it out, some anti freeze will spill. There is a paper washer between the air slide and the block. It will probably disintergrate if you take the air slide out for a cleaning and inspection