2003 nissan navara D22 zd30 turbo spill valve location ?

Turbo spill valve??????

There is a spill valve on the back of the injector pump between the four injector lines, it's a round thing with two wires that run up to the electronic pump controller mounted on the top of the pump.

Your not talking about the swirl control valve?

Spill valve as in the turbo dump valve or waste gate?
On a diesel they are generally located in the turbo turbine housing and have a pressure actuated valve that dumps excess boost into the exhaust dump pipe just down stream of the turbo.