Fuel Pump

[PewterBird]

I want to clarify what the mechanic sayed.

He had a fuel pressure gauge on the car, when the car is running, it sits somewhere between 45-50 pounds, when he turns the car off the pressure slowly falls down to zero. He sayed this is a bad fuel pump, becuase it isn't holding any pressure when the car is off.

Is this all correct, because I am thinking that if is creates enough pressure when it is running then the pump should be ok. Isn't there a fuel pressure regulator, and its job would to keep pressure in the lines right?

[chas]

is he trying to solve a particular problem? hard starting?

how long does it take for the pressure to bleed off?

the system should hold pressure for a couple hours. however, you could have a bad pressure regulator or injector that is allowing this leak down. yes, the fuel pump could be leaking too.

[HPbyChevy]

I was under the impression that a fuel injected vehicle's fuel system was under constant pressure, i.e. the need to depressurize the system in order to work on it.