Stalling when a/c is on. Won't hold idle.
 

Hello, Ive done so many repairs to my '90 626 DX, I could'nt remember them all. Anyway, right now the problem i'm having is when I have the a/c on, the idle will drop almost to the point of shutting off (if it does'nt stall of course) when i'm coming to a stop or just take it out of gear. It seems to hold the idle okay when a/c is off. What part would control this and where would I find it?