Fuel Injector: Description and Operation

Fuel Injector:

PURPOSE
The fuel injector atomizes and meters high pressure fuel delivered to the engines intake system.

LOCATION
Injectors are mounted in the lower intake manifold and positioned so their tips are directing fuel just ahead of the engine intake valves.

CONSTRUCTION
The low carbon steel electro-mechanical device consists of:
- A solenoid
- Needle and valve assembly.
The solenoid has an armature and a needle or ball valve with a spring holding the needle or ball closed against the valve seat.

OPERATION
The Electronic Control Assembly (ECA) activates the injector solenoid causing the pintle to move inward off the seat, allowing fuel flow through the orifice. The amount of fuel delivered by the injector depends on the amount of time that the injector nozzle is open.