1992 Stanza wont idle until warm

In cold weather, 40 or less. The car wont idle, you have to rev the engine to about 1000 plus RPM or it will stall. Once she is warmed up she runs fine. I noticed there is a cable that connects to the throttle and goes to a diaphram wich then has a vacume line that goes to a motor on the drivers side fender wall. I tested this motor with a standard test light and it doesnt appear to be getting power. QUESTION: What is this motor and where does it get power from? Does it have anything to do with the symptoms? Please help.