Fuel Injector: Description and Operation

PURPOSE
The natural gas engine fuel injectors are electro-mechanical devices which meter fuel delivered to the engine. They are mounted in the lower intake manifold and are positioned so that their tips direct fuel just ahead of the engine intake valves.

COMPONENTS
The natural gas engine fuel injector bodies consist of the following:
- solenoid
- needle and valve assembly

NOTE: The natural gas fuel injectors differ from gasoline fuel injectors and are not interchangeable. Natural gas fuel injectors can be identified by an Aqua Cap on the injector body.


OPERATION
An electrical control signal from the Powertrain Control Module (PCM) activates the fuel injector solenoid allowing fuel to flow. Since the fuel injector flow orifice is fixed and the fuel pressure drop across the injector tip is constant fuel flow to the engine is regulated by the length of time the solenoid is energized.