So we bought a used 06 Liberty this past summer. I replaced the radiator couple of weeks ago because it had a bad leak. Shortly after that it started stalling, and eventually wouldn't start at all. After reading engine codes and coming up with a misfire in cylinder 4, we replaced the spark plug and the ignition coil in said cylinder. That still didn't do anything, so we dug further and eventually diagnosed that the fuel pump had died. I bought a new fuel pump from carparts.com, and installed it. It worked! Like a charm! Car fired up and ran just fine! It still idled a little rough, so I thought there might still be a misfire going on, but at least the car was running. Yesterday, while my wife was driving it, she lost power briefly, but then it was fine. Today (4 days after replacing the fuel pump and getting the car back on the road) it started running really rough and losing power. When I took it back out a little later, it stalled as soon as I got it out on the road. I got it started a couple times, but had no power pand then wouldn't start at all, just like it did last time. A couple of notes that may or may not be relevant: 1. After I replaced the rad I never got the coolant system bled properly, I know I still have an air bubble in there somewhere because it only gives heat when it's moving (really nice in winter in Maine) 2. When I did the fuel pump one of the rollover valves broke on the tank. Because we couldn't replace the valve without replacing the whole tank, and because it didn't seem to be a critical component (unless the car rolls overboard ofc) we just left it broken with the intention of replacing the tank when we could afford to. Really need to get this back on the road asap, as this is our only road worthy vehicle right now. Any help would be greatly appreciated!