Hard start after a few hours?

Hi:

The first thing that comes to mind is whether there are fuel injectors leaking down when you turn off the engine. If you wait long enough, the fuel will evaporate. If you try starting it in a few hours, it may be flooded.

When it does start, have you ever noticed any black or dark gray smoke from the exhaust or a strong exhaust odor for a short period of time?

One way to check if there is such a problem is to do a leak down test on the fuel system. Basically, you connect a fuel pressure gauge and turn the key on so the system is pressurized. When the key is turned off, watch how quickly the pressure drops.

Here is a link that explains how to check fuel pressure. Watch the video at the end. When he finishes, note how the pressure remains. At that point, you will want to watch how quickly it drops.

https://2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator/

I attached the fuel specifications below for a 6.0L. There is no 7.4L listed. Let me know if that was a typo.

Take care,

Joe

See pic below