sounds to me like it cranks longer than usual. common problem, usually fuel pressure is leaking down from the check valve in the fuel pump. taking longer for fuel to reach the fuel rail and start the jeep.
check your fuel pressure if possible. most jeeps don't have an external pressure regulator, if you did it would be on the fuel rail, and have a vacuum line going to it. almost no jeeps have them though, its all in the tank.
usually replace the fuel pump assembly, not sure if you can do the valve seperate.