why does it run great then shut off and not start again till next day?

I can go out and start it up no problems. I timed it
and it shut off after 30 minutes of running.
Consistently. It showed water temp at about 200
degrees. No codes showing up and if I try to give it
gas when it shuts off it has no effect. I can attempt
multiple times to restart to no avail. It has a couple
of times restarted but shut back off after a minute.
I have disconnected the battery and tried to started
it after 20 minutes diconnected but no results. I
sprayed starting fluid in the intake and tried and it
actually was trying to start so it does have effect. I
have come back to it a day later and it starts right
up. ........ I parked it originally because when I was
driving it, it acted like it shut off and then if I
punched gas it went back to normal running. Did
that 2 times to me and I figured it was good idea to
solve the problem. Any help please? What could it
be? I know not the fuel filter as I replaced that.
Thanks in advance.