I hadn't driven my JEEP in about two weeks. It started normal and I let it run a couple of minutes before I left. I headed out and then I got this coughing and bucking which decreased power. Brought it back home and it idles fine. Raised the hood and saw this vacuum line laying behind the distributor. The way this backfired through the carburetor it made me zero in on replacing the vacuum line. Problem is that I see no ports from which it could have come. Here are photos around the carburetor. I've looked in the FSM and don't see where this line could have been. Any thoughts? Points, condenser and rotor are fairly new.