Went out and started the Jeep, again today and it wouldn't stay running. The has gauge reads empty, but there's at least a quarter of a tank. Revving the engine makes the gauge go up, but it still struggling to stay running. Thoughts?

 

Has the hallmarks of a voltage problem. Hence the level working a little better when revving. The ground connection for the fuel pump is behind the driver side rear trim (behind the spare tire). That would be the first place to inspect and clean up any connections to the body. Then check the grounding strap that goes between the body (passenger fender) and the battery negative terminal. The fuel pump connector itself could be in bad shape as well. Though it tends to sit up above the fuel filter. But it is worth inspecting (disconnecting/reconnecting, spraying out with contact cleaner) as well.