1971 240z: I removed the valve cover and manually operated the fuel pump arm. When I release the arm, it sends fuel to the carburetors. I noticed that it takes a noticeable amount of time for the arm to return to its starting position on the cam lobe. During this return, the pressure has a max of 6 psi. I can confirm that the return line produces a visible spray of fuel into a glass jar. Once the spray from the return line diminishes and I see the pressure drop below 3 psi, the pump arm is ready for another cycle.
With the engine NOT running, should I assume this is normal behavior?
My concern is the time delay. If this delay remains during engine operation, the fuel pump arm would float and never have a full stroke. That's assuming it is supposed to always have a full stroke 100% of the time.