Over the weekend I could not replicate hesitation at >3K rpm if in 3rd or 2nd. I did not get a chance to go buy a fuel pressure gauge so pressure at fuel rail at idle remains a mystery but if you read below I think it will probably be within range.
Then, yesterday it started stalling only if I bump the pedal from a standing start and takes a few cranks to get it running again. The engine turns over fine but will not catch like it usually does. If I push the accelerator slowly it does not stall and accelerates smoothly.
Engine continues to idle smooth as silk and will rev up to 3K (did not go beyond that) in neutral without conking out.
My inexperience pushes me in the direction that this is the fuel system acting up as I just changed the fuel filter and this stalling out phenomenon emerged (high speed hesitation pre-existed prior to fuel filter change) BUT the engine seems to be getting fuel all right while in neutral and that seems to contradict the fuel system problem theory.
The problem does seem to occur when fuel flow is increased at a rapid rate i.e harder acceleration.
92 400E 128K
99 GMC YUKON 88K