The 4.0 is distributorless, but it still has a SPOUT connector. Unplugging it forces the computer to a base timing so that you can check it and then plug it back in and check it again. There's also a similar looking timing retard connector up there in case you get ahold of some bad gas.
I might be late to the hot restart fuel discussion, but I crawled under my '94 4.0 one day after off-roading it in the heat in the desert all afternoon and I could hear fuel bubbling or squirting back into the gas tank through presumably the return line. I think I read somewhere that Ford started putting a thermal spacer between the fuel rails or something and the engine later in the '90's because of that issue, and that you can pull the spacers from a junkyard and put them on earlier 4.0s. Or just keep drawing funny looks as you act normal while your engine sputters and barely runs while in the middle of nowhere...
Oddly enough, mine had that problem in March in Moab when it was 80+. But it had no problems with hot restarts when I went back to Moab in early June and it was 100+.