2000 Other Nissan Models FUEL PUMP

Hello I have no info on your car ie engine model etc but here goes anyway! Firstly if its an electric pump(or intank pump) you will hear a buzz when engine on and you listen round tank(probably under rear seat)if its mechanical its unlikely at fault as these usually just "give up" has it been servicied recently? It sounds to me like a fuel filter clogged, I would scan the ecu for codes, could be a coolant temperature sensor thereby flooding engine when hot(engine fuel mix is enriched when cold and leaned out when hot ecu takes reading from coolant sensor to determine how hot engine actually is
hope this helps
regards irishmobilemechanic