Ok, Im brain dead this week and never looked at my YJ. The pic attached is from a 4.0 YJ and you can see the hard plastic lines. One is fuel supply and the other return. Hopefully Macho will chime in here as he rebuilds these things in his sleep.
Yes they are fuel injected, however if you look at the fuel filter you'll see rubber fuel line and screw type hose clamps. at either end. That being said I cant see why one cant replace those plastic lines with good quality FI type rubber fuel lines. The engine ends are metal and look to have barbs on them and the plastic line shrunk to a tight sit. The other end the same but with a small fitting with quick disco's.
Worst case would be to cut the metal lines leaving enough to work with and use compression fittings with a male barb fittings and the rubber fuel line. I used comp fittings once to repair a worn thru metal brake line on a 4x4 burb abd never had any problem with it leaking or?? under the hyduralic pressure. I really doubt you'll find those lines new anywhere if you want to stay factory, but you might try Collins bros in TX for used ones.