I have been working on a '77 280Z fuel injection system that will run intermittently. It seems to run out of fuel after a 40 seconds or less. I pulled the fuel line off the fuel rail after the fuel filter and placed it into a bottle, the fuel pump will begin to pump fuel when the ignition is turn to start, and stops pumping fuel when the ignition switch is in the on position. Is this normal or should it begin to pump when the switch is on position. If this incorrect would suspect the ignition switch or the fuel injection relay. Any help with this would be greatly appreciated the car was going to a driving school in Feb.