1998 Dodge 1500 hard warm starts

I have dodge that has a hard time starting after its warm.... starts up fine in the mornings but after i stop the engine and try to restart after a 1 hour or so i will have to grind it to get it started again.... if i leave it set for 5 + hours it will start fine...... on the other hand if the day is hot i have the same problem when i first start it up (cold mornings are fine ..... hot afternoons are killer)

Thanks for any light anyone can shed

No codes
Runs fine after i get it started
V8 5.2L

Try replacing the engine coolant temp sensor located right behind the thermostat. There is one to the left behind the alternator, but that is for the gauge. Also the intake air temp sensor might be worth a try. It's on the passenger side front of the intake. Both sensors are cheap and worth the try. Do one at a time, so we may know which one fixes the prob. If they are even bad. If you have a Haynes manual there is test procedures for both sensors also.

Thanks for this thread! This sounds a LOT like what my truck is doing, but it has to sit longer than 5 hours. I have to floorboard the gas to start it. Once it's running, I have to stay on the gas to keep it running. Which does cause a little discomfort for nearby drivers.
Makes me suspect the fuel pressure regulator as the thing won't restart when warmed up without having to flood the thing and blowing a bunch of black crud out the exhaust.
Did some price checking: The coolant sensor costs about $20 online. The intake air sensor runs about $100, so definitely test both before shelling out some serious buckage.
It might also be the fuel pressure regulator (another $100 new) which means dropping the fuel tank and carefully replacing it in the fuel pump. You can get a the whole fuel pump from a salvage yard for about $100. Seems a common figure anymore. A new fuel pump will run about $250+.