A/C and a jumpy idle

Actually the car is surging. The A/C causes a load on the engine and the engine responds to the computer to elevate the throttle and compensate for the pull of the A/C. Under load the surging stops. You need to be looking for a possible vacuum leak, hose, etc. Purge the cooling system of air in the system. This is purging air from the antifreeze and not the a/c. There is a bleeder on the top hose near the block. Do it with the engine running and at normal operating temp. There are other things to look for as well. IAC could be plugged. O2 could be failing. EGR valve could be dirty or need replacing.