How does the fuel pump work in a PA-28 and when should I use it? Just started flying again after 14 years and I'm taking this to the finish line this time. All my time, up till 10 am today, is in a C172. I did fly a PA 28-151 today and liked it.
I do have some questions about Pipers (specifically PA 28-181 and 28-151):

Does the fuel pump has to be on the entire flight?
Is there a fuel pump for each tank?
If the pump doesn't have to be on the entire flight, how does the engine/carburetor get fuel considering the engine is higher than the wings?
The PA-28 Family of aircraft have two fuel pumps, an engine driven mechanical pump that is always pumping (so long as the crank shaft is spinning) and is considered the &quot;main pump&quot;. The airframe also has an electrical backup pump that can be actuated by the pilot. The tanks do not have their own pumps.
You should check the POH for your airframe but generally speaking in the Archer and Arrow I fly the electric fuel pump is turned on:

checking fuel pressure before start
during take off
climb out
when switching tanks (I also run it for 30 seconds after switching tanks incase I either need to switch back and to maintain fuel pressure at a critical time in the event of a failure of the mechanical pump)
on approach
landing/go-around
in the event of a mechanical pump failure
while practicing maneuvers (S-Turns, turns around a point ETC)
during a practice stall
Engine power loss in flight
Loss of fuel pressure

Most of the above items can be found in this POH.
Note: You should not be running the electric fuel pump for the entire flight, like anything this is a component that can burn out and it should be used when needed or dictated by the POH.