Hesitation nobody can figure out!!!!

My Nissan Stanza hesitates when it's warm and I've tried almost everything!
Any ideas??

something is clogged or maybe a vaccum leak could be like a million things though

My fuel pump gave way a week ago.
When I changed it, I had no hesitation for one whole morning, so I'm gonna check fuel pressure tomorrow.

The fuel filter was changed not long ago, so I'm gonna trace the problem back from the filter to the tank.