Section XIV. Repair of Fuel Injectors

word "TOP" on gasket is visible. Be careful not to

*TM 9-2815-213-34

dislodge grommets as gasket is lowered over

rust preventive lubricant and install.

Tighten each in

grommet retainers.

sequence shown in figure 3-48.

f. Using cylinder head lifting plate (45, fig.

B-28) as shown in figure 2-19, capscrews, lift head

with suitable hoist and lower into place over

dowels.

g. Blow all liquid and dirt from cylinder head

capscrew holes with compressed air.

CAUTION

Keep rust preventative oil from internal

engine parts to prevent corrosive dam-

age.

h. Coat short cylinder head capscrews with

Section XIV. Repair of Fuel Injectors

3-71. General

NOTE

This section covers the disassembly, inspection,

repair, assembly and testing of injectors (fig. 3-49).

The injector is a simple mechanical unit which

Injector bodies and plungers are class fits, do not

receives fuel from the fuel pump, under pressure,

interchange.

and injects it through fine injector cup spray holes

b. Remove and discard O-Rings

into the combustion chamber. The description "PT

from injector

Injectors" is only used to in the cate that the injector

body.

is used with the PT fuel systems. The PT injectors

c. Disassemble clamp securing screen to injector

are mounted in the cylinder head and are cylindrical

body.

in shape. 'The V8-300 engine uses of PT type C

injector. It consists of two major assemblies: injector

NOTE

body and plunger; and the injector cup. The orifice

descriptions below are given for functional main-

Do not remove adjustable orifice plug from inlet

tenance purposes.

groove.

a. Adjustable Orifice Plug. The orifice plug

d. Place injector in injector cup wrench (30,

used in the inlet drilling of the cylindrical injec- tor

fig. B-28) and install in injector holding fixture

adjusts delivery of fuel. Fuel delivery is ad- justed by

(29, fig. B-28) as shown in figure 3-50.

changing the orifice plug or by burnish- ing the plug in

e. Remove injector cup; note size markings on

operating position. Some ori plugs have a flange and

injector body for future reference.

require a gasket bene the flange.

f. Remove ball retainer, ball, and gasket from

b. Drain Orifice. The drilled orifice in cup E

top of injector body, discard gasket.

of the injector is the drain drilling. This orifice is fixed

g. Place injector plunger in suitable holding

in size and must not be altered in any way.

device with spring retainer upward.

c. Metering Orifice. The orifice in cup end

h. Pull link and retainer as an assembly.

of the injector allows fuel to enter plunger bore and

i. Using a collet type hand tap holder, pull

cup; do not alter in any manner.

injector links (fig. 3-51).

3-72. Disassembly

3-73. Cleaning

(fig. 3-49).

Clean injector components in accordance with paragraph 2-

a. Lift out injector plunger and spring. Tag

mating parts.

3-74. Inspection

Perform general inspection of components in accordance

with wear limits in repair and rebuild standards (para. 3-183).

Detailed inspection of injector components follow.

3-23