fuel pump relay.
 

if the cars fuel pump relay is bad will there be fuel at the fuel rail?

RE: fuel pump relay.
 

Depends on the car. As an example, on 3rd gen cars, when the key is first turned ON,the pump relay is used topower the pump to prime the system. Once the car has started and the oil pressure is above 5 PSI, a pressure switch built into the oil pressure sensor closes,and provides the power to the fuel pump. So you could have bad fuel pump relay, and if you have a good starter that can spin the engine fast enough to get the oil pressure up, the fuel pump will run and build pressure in the fuel rail.
On some other cars there is only one path for power to the pump, and if the pump relay is bad the pump will not run and there will be no pressure at the fuel rail.