I believe the sp1 and 2 are wired the same as far as fuel pump and kill logic go.
I just went over exactly this with a guy earlier today
First thing to do is verify the engine stop relay is working. Just hold the relay in your fingers and feel for a click when you toggle the kill switch
If the engine stop is clicking, do the same with the fuel pump relay. Check for a click on, then click off a few seconds later
If the engine stop clicks with the kill switch but the fuel pump doesn't, check that the wiring to the ecu is in good shape, the brown/black is provided a ground by the ecu to run the fuel pump relay.
If both relays are clicking and you have verified 12vdc on the black/white wire, chances are it's the pump.
The power to the fuel pump comes off the fuel cut relay on a brown
The low fuel sending wire is a brown/black.
Hope this helps