Indeed... they call it "fuel pump relay" because it's the relay for the fuel pump.

 

Attached are scanned schematics from '83 FSM. They were fold outs that had to be scanned in pieces. Hope they help.

 

^^^ I think you forgot to "attach" the attachments.

 

There are 3 different fuel pump relay schemes through out the 280zx production.

That's just for normally aspirated cars while the turbos have at least two different schemes with one having a fuel pump controller that varies voltage to the pump depending on conditions.

Two involve alternator and oil pressure sensors to determine running and the other only has one relay without oil pressure sensor or alternator input needed.