have to close choke plate?? to keep car running-why??

Initially I thought massive vacuum leak, I like to use a propane torch that's unlit and the oxygen mixer taped over and wave it around the motor, less messy than wd40. What's your idle speed? Maybe your normal idle is way too low and with the choke closed the idle speed increases with the fast idle cam. I like to set my choke idle at 1500 and normal idle at 1000 in neutral, 800 in gear. What's your timing set at? Manifold vacuum readings?