get your hands on a fuel pressure guage, sounds like your losing fuel pressure in the lines. If you run the jeep shut it off and start it right away does it fire right up? If you run it, shut it off and let it sit for an hour and go start it, do you have to crank it for a while before it starts? My guess is your having to build the fuel pressure back up in the system. My '91 had the same problem and jeep had a fix for it (replace hose and clamp to fuel pump in tank). Yours is a '01 so I don't know if it will be the same fix, but it sounds like the same problem. Could be a bad pressure regulator (pull vacuum line @ regulator and check for fuel), check valve in fuel pump, leaking injector. Definitely get your hands on a pressure guage to make certain. Hope this helps