FPR?

[0xDEADBEEF]

1999 K2500 7.4 160k miles

Hot starts are sputtery if it sits more than 20 minutes, and the idle surges in drive after it warms up too. When it's cold no problems, fires right up and idles fine.

Symptoms of a bad fuel pressure regulator?

Gas mileage seems to be holding steady at 10 mpg everywhere.

 

[PlayingWithTBI]

Fuel pump, FPR, leaking injectors all could give you the same symptoms. Got a pressure gauge? See what you get KOEO, see if it holds pressure after shutting it off.

 

[Supercharged111]

Fuel pump, FPR, leaking injectors all could give you the same symptoms. Got a pressure gauge? See what you get KOEO, see if it holds pressure after shutting it off.

This.

 

[0xDEADBEEF]

So 5 hours after driving it, basically 0. Slight dribble when depressing the valve.

Key on it shot up 50 psi. When idling it bounced around between 48 and 55, not sure how accurate that it is.

Turned off and dropped about 2 psi per minute. I quit watching after it got to 38.