i have the exact same problem as you except im a aristo 2jzgte. Starts great cold, after i drive it around and come to stop and let it sit for a few min and try to start it, it hesitates and im lean at 17 afr on the wideband for about a min then all is good. On mine though all fuel system is new pump, afpr, fuel injectors, fuel filter, fuel hanger even feed and return lines. i have a fuel pressure gauge installed on my Aero FPR and im at 38 when i shut it down and then it starts to creep slowly down to zero over about 3 min. I even had the FPR return line clamped after shut down and it still does it which leads me to think either injectors or fuel pump, but ive already replaced the pump twice because of this with a denso mkiv tt pump. Weird thing is when i had the new pump out of the box before installation i smoke tested the outlet port and it began to bleed down as well on a new pump! shouldnt check valves prevent this. I hope it is fuel drop related because ive checked everything else i can think of related to this problem.