Fuel Injector (Crown Valve)

tag indicates the nominal output of the injector in

3-14. Fuel Injector (Crown Valve)

cubic millimeters.

a. General.

(3) Each injector control rack is actuated by a

(1) The fuel injector performs four functions.

lever on the injector control tube which, in turn, is

(a) Creates high fuel pressure required for

connected to the governor by means of a fuel rod.

efficient injection.

The levers can be adjusted independently on the

(b) Meters and injects fuel to exact amount

control tube, thus permitting a uniform setting of

required to handle load.

all injector racks (para 3-13 g).

(c) Atomizes fuel for mixing with air in the

b. Removal. Refer to figure 3-20 and remove fuel

combustion chamber.

injectors and fuel lines.

(d) Permits continuous fuel flow.

NOTE

( 2 ) Each fuel injector has a circular disc

Install clean shipping caps on the injector fuel inlet

pressed into a recess at the front side of the injector

and outlet and on the fuel connectors. Cover the

body for identification purposes. The identification

injector hole in the cylinder head to keep out foreign

Figure 3-20. Fuel injector, removal and installation.

c. Fuel Injector Testing.

maintain a pressure of 1600 to 2000 psi. Inspect

for leaks. Relieve test pressure slowly - to prevent

and p l u n g e r m o v e m e n t .

(1) Injector

rack

Check to see if the plunger works freely in its

damage to test gage.

WARNING

bushing by placing injector against a bench and

The injector must always be held in

depressing follower to the bottom of its stroke while

such a way as to prevent any fuel from

moving the rack back and forth. Failure to produce

penetrating a person's skin. Fuel which

a free rack indicates internal parts of injector are

e n t e r s the blood stream could cause

dirty or damaged (fig. 3-21). With injector

s e r i o u s infection or death.

m o u n t e d in test stand (fig. 3-22) pump and

3-33