How do I know if it is the fuel pressure regulator or if my fuel pump is going out?

Question

My car hesitates when sitting nd lags when first accelerating. Mostly when Rpa r un
der 1000

Answer 1

you most likely have a bad fuel pressure regulator since the car is hesitating but you could also be clogged fuel injectors 

a bad fuel pump would have no pressure.

see specs below