hm if the engine revs up with no issue maybe its not fuel pressure.. when i had fuel pressure issues, i couldnt get over 2k rpms on occasion and vx would sputter when i stopped at a light or somethin as soon as i stopped completely rpms would drop really low and would sputter then 98% of the time recover.. other 2% it would stall...
had the occasional hard start as well (after 5-30 min of the engine sitting after driving) i would start and engine would crank for awhile before turning over.. and rpms would move sporadically between 500-1500rpms and the vx would want to die unless i kept my foot on the gas for a bit, then things would calm down and would drive fine
if your engine is revving up normally i would guess a transmission/tcase issue like others have mentioned