Injection Nozzle section receives high pressure fuel injected into the combustion chamber. When pressure fuel injection pump is pumped by a greater pressure than the spring load, the energy pushing the needle nozzle upward. This causes the spring to be compressed and the pressure of fuel injected into the combustion chamber.

Injection pressure can be tuned by adjusting shim thickness I differentiate, which effectively turns the load on the spring. This parts accepts the high pressured fuel and injects it into combustion chamber. When the fuel pressure pump pumped by hypodermic Becomes bigger than burden of spiral spring pressure, its energy will push the needle nozzle to up.