panamint

I am helping son with a problem. They have a 2005 Lexas iS 300. They were driving at highway speed at the car died. Pull over try to start, turns over but won't start. I drive an hour to get there. Swap fuel pump relay still won't start, prime the fuel pump working ignition still no. Have it towed 100 miles ( thank god for AAA plus) back to my house No coded stored. Tow to local shop starts up, they check no codes, good fuel pump pressure, good spark. It is acting like a fuel problem, I have them change the pump. even though don;t know for sure but can't take chance with kid and family driving back to Vegas from Big Bear
Shop says rubber seal dried and cracked, so hoping it was sucking air. Thing is running great seems running better so I'm hopeful.
The kid just called dies on the freeway in Vegas( he lives there)
Good old dad can't keep fronting money lol Anyone have any ideas

Thank You very much.
Scott
Car was low on oil when I got to it. Put 3 qts ( I know kids ) in when it died the first time,
Had car towed back to his apartment Unloaded off tow truck started right up ran less them a minute, ran real rough and died, Wont start again