Fuel Injectors

GENERAL INFORMATION

Fuel Injector

1. INJECTOR BODY

2. SPACER GUIDE BUSHING

3. VALVE SEAT BUSHING

4. VALVE BALL

5. INJECTOR TIP

6. SPRAY PLATE

7. NOZZLE BODY

8. VALVE SPRING

9. SOLENOID HOUSING

10. SOLENOID

11. INLET FUEL FILTER

The MPI fuel injector supplies fuel to the intake manifold for an individual engine cylinder.

The injector solenoid valve is controlled by the ECU.

The injector valve of the ball or needle type is normally closed. Fuel flows through the channels inside the injector, through the open ball or needle valve, and is injected into the

intake manifold, see the illustration Fuel Injector. Six holes in the spray plate provide metering of the fuel flow and form a cone-shaped spray of finely atomized fuel in the injector tip. From the

injector tip, fuel enters the intake manifold, where it is further atomized and evaporates before entering the cylinder. An injector with a

leaking valve causes a drop in fuel system pressure after

the engine is switched off. In some cases this defect causes difficult engine starting (requires prolonged cranking with the starter). In addition,

a small amount of fuel leaking through the faulty injector valve leads to.

engine run-on (dieseling) after the ignition switch is turned off.