Not sure where to start on diagnosing. If the engine dies suddenly, then restarts without using the starter (assuming you have a manual transmission), I'd suspect its either a bad electrical connection or a problem with fuel flow at the pump or filter.
Being that you're living in a tropical, coastal location on the ocean, and given the history of wiring problems the Sportys have had, I'd disconnect, inspect, clean and coat with dielectric grease (or a corrosion inhibitor), and reconnect all of the connectors on the engine harness. And check the wires just behind the connectors too. I've found corrosion creeping up the wire from the connector on a few of mine. Might want to check the battery cables too. But if you're not losing all electrical power when the engine dies, then it's probably not a ground connection-related problem... probably.
If you have never changed the fuel filter or have knowledge of it being changed, that might be a good thing to look at. Usually, fuel pumps are working or dead, unless there's an issue with the wiring. You can access the pump and the wiring harness under the rear passenger seat, if you didn't know that already.
Are you getting a check engine light or any OBD codes? That might help sort things out. That's all I can think of at the moment. Hope that helps.
1997 Sportage 4x4, auto-trans, Warn manual hubs, 4" UPYOURKIA front lift, TJ 106AA rear springs, 2-5/8" body lift, 31x10.50 treads, SmittyBilt SRC front and XRC rear bumper, swing-out tire mount, OBX LSD front diff, Track Finder rear locker, 5.38 R&Ps and... really crappy gas mileage! <img src="/forums/images/graemlins/shiner.gif" alt="" />