2005 Jeep Grand Cherokee hot starting problem - help!

Hi all! Long time watcher, first time poster etc etc.
I’m having starting issues with my '05 Grand Cherokee (4.7L V8 engine). It tends to only do it when it’s hot - it’ll start fine when cold, but once it’s up to temp it’s a bit 50/50 as to whether it’ll cooperate. It’ll splutter and die, although if you leave it for half an hour or so it’ll usually go again (albeit a bit reluctantly).
The check engine light came on recently with the main code P0174, fuel system too lean. Secondary codes are P0171 and P0420.
I’ve cleaned the battery terminals and replaced both the Throttle Positioning Sensor (as an earlier diagnostic check suggested) and the Coolant Temperature Sensor (ECT). Upon changing the sensors it seemed to work better for a few days but ultimately slumped back into its bad old ways. Note: it doesn’t have a MAF sensor.
Another post on Car Talk suggested to try cycling the key 4-5 times before attempting to start the engine next time it didn’t cooperate; if that worked, it would point to a low/no fuel pressure issue. I tried this a couple of days ago and, bingo, it worked.
I think this all points to a fuel pressure issue. The question I have is: what do I do now? Older models appear to have had a fuel pressure regulator mounted on the fuel rail that could be replaced or checked, but I’m pretty sure this one is all built in to the system behind the back axle.
I’m just about as far from car-savvy as possible and I suspect this may be beyond my meager abilities to fix. Should I just send it to a mechanic? Or is there something I could try to swap out first?
Just let me know your thoughts. Thanks all!

A bad crank sensor effected by heat will cause a no-start condition.


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