vacuum canister

I had my bumper ripped off in a collision and that's when I discovered the vacuum canister inside the bumper on the passenger's side. My XJ is a 93 sport, 4.0L HO. This cannister is a ball shaped one. I only found one line that lead to it. I have another cannister and it has two nipples one labeled VAC and the other has no label (pretty sure it's the right canister but not for sure). I would think the other one is a return line. I've seen different size canister's with multiple nipples on them on XJ's dependent on year and model. Where does the other line connect to? After the "collision" my temp controls went screwy, idling higher and running rougher. I connected the one line to the cannister and plugged the other nipple. That fixed my temp controls and it improved the idle but is still not running right. The cruise control works fine. When I shift this auto into gear it lurches and wants to take off. It seems to be overheating too...gotta look into the thermostat. Please help!