Priming pump

[Collers9640]

It's been a while some forgive me but.
I pump on a 2nd gen primer on my engine before I pulled it.
My question is, when the pump is primped you should no longer be able to push the button correct?

[thrashingcows]

Nope...that is why there is return fuel lines...one from the IP and the other from the injectors. It might get a little tougher to pump, but never to a point that the lift pump will not be able to move fuel.

[RCCUMMINS89]

The regulating spring on a piston pump will go into a "neutral" area. However, you'll always see the same pressure, because the primer is on its own separate spring. Meaning the pressure on a piston pump primer will never change.

[jethro]

will it help to turn the key on to open the fuel solenoid so the fuel goes all the way to the injectors ? (or a few of them)
or can the fuel get through the pump when the pump isn't turning..... ????
T