The governor(also called regulation system by volvo) is a system of levers under the timing cover that controls the fuel output from the injector pump, it is not located between the lift pump and the injector pump. The throttle control connects through the governor to increase/decrease the amount of fuel delivered to the injectors by the injector pump.
These 2 springs that control the tension of the governor arm that connects to the injector pump cost about $8-9 AU dollars each, but it will cost a few of hundred dollars to replace due to needing to replace 2 gaskets, 2 seals
, and 2 O-Rings, and an hour or two of labour to replace them!!!
A bit ridiculous in my opinion.