Acceleration hesitation on a 99 4 runner

my 4 runner has a hesitation problem that just showed up one day, i have tried replacing fuel filter’s , fuel pump and fuel pressure regulator( all toyota dealer parts). the only thing that helps ispinching the return fuel line , then it runs like new . can u’all please help me

In all of this time & through all of the parts did you actually measure the fuel pressure? Don’t assume that a new fuel pump means everything is well with it.