Car is getting no fuel no start

[Infiniti710]

I have a 2002 Infiniti i35 with 140,xxx miles

Last week I got to the store and when I came out to start my car it started up and was shaking really bad, then it just shut off by it self.
I towed it to my house and the next day I try to start it and nothing.
It wouldn't start at all. I checked for fuel pressure and nothing.
One of my friends came over. He took out my backseat and unplugged the wires that go to the fuel pump, he checked them with that light tester,
And the light was very low. He told me it was my fuel pump, but I burly put a new pump like 3 weeks ago, so he told me it gots to be the fuel pump relay.
I changed the fuel pump relay and still nothing. The fuel pump fuse is good.
Alternator, battery and fuel pump are all new less then a month.

Can it be a bad ground on the fuel pump?
Or what can cause that wire that goes on top of the fuel pump to not suck out power out the pump?

[NutriaforBreakfast]

what about the fuel regulator?

[Infiniti710]

what about the fuel regulator?

Is the fuel pump regulator underneat the Back seat too? How would I know if it's the regulator that's bad.

[NutriaforBreakfast]

http://www.nicoclub.com/FSM/I35/2002/ec.pdf

Page 58
They call it a fuel dampner