hesitation under light throttle

[jim-00-4.6]

2000 RR 4.6, 129K miles
light to moderate acceleration, truck seems to hesitate.
idle RPM sometimes drops for no apparent reason.
this morning, it stalled when stopped at a light. (started right back up)
Replace Engine Light NOT illuminated.

Hoping your guess may be better than mine, as my guess is "WTF?"

 

[KyleT]

CKPS might be on its last leg? or fuel pump starting to go maybe. thats where I would start.