My suv, won't take the gas, when pressing the pedal.....

It won't take gas when pressing the pedal. It started when i was going up a hill, and had to give it more gas, The motor started dying down, until i let up on the pedal, it started running back to normal. It final cut all the way off. and when it does crank up it's running rough. like it starve n for fuel. I already change the fuel filter no luck. i haven't change the fuel pump yet, but i was going to do that next. What does my fuel pressure should be on this vehicle.and does it should have the same fuel pressure at all times, even when the car sit and shut off... please help me....