jeep vacuum issue, what is that part?

I've got a 1990 wrangler with the 4.2 straight six. I have found solutions to most probles but don't know what a certian part is. it is a small silverish cylinder shaped thing with vacuum hose going out near the bottom towards the carb, it is about the size of a vienna sausage can. any ways the jeep only runs when set to idle at 1700rpm(i can readjust the carb) however when I set it to where it runs at 700rpm idle it will die if I don't let it down slowly. I know the vacuum system is not fully hoocked up but I need/want to know what that little can is called so I can replace it because a nipple broke off and it is 20yrs old anyways. if it helps it is held on by two screws side by side. I have Diagrams but can't make sense of them at all My guess is it would be "TAC TEMP SEN" or "CARB SOLEVAC" or just a "SOL" any help would be great here. I just want to know wht that canthing is called