GMC 4000 Series Service Manual page 384

NOTE: Control unit and rod are held in place
by a retainer plate which is attached by two screw s
equipped with lock wire. Control unit and rod re­
tainer plate is shown in figure 32.
4. Remove lock wire from plate screw s. Re­
move screw s, plate, and the spacers which retain
the control unit, then disengage the control rod
from lever.
5. Use metal dye or paint to place index marks
on control unit flange and on pump body (fig. 31).
NOTE: MARKING THE PARTS IS NECESSARY
SO THE CONTROL UNIT CAN BE INSTALLED IN
ORIGINAL LOCATION AND AVOID CHANGING
THE PUMP CALIBRATION.
6. Carefully withdraw the control unit assem ­
bly from bore in housing, using two thin screw ­
drivers diagonally across from each other to start
the unit out of bore.
IMPORTANT: The dot on the pin must be up,
otherwise pump will be out of calibration (fig. 30).
7. Remove O-ring seal from control unit.
STOP PLATE
C A M N O S E
G O V E R N O R CO VER
\
DRO O P SCREW
FUEL SUPPLY
PUMP
G O V E R N O R
SP RIN G S
G O V E R N O R
H O U S IN G
G M C S E R V I C E M A N U A L
FUEL INJECTION SYSTEM— TORO-FLOW ENGINE
EXCESS FUEL
.STARTING DEVICE
CONTROL
ROD
FULCRUM
LEVER G O V ER N O R
SLEEVE G O V ER N O R
W EIG HTS
Figure 3 2 — C u t-A w a y V ie w of Fuel Injection Pum p
INSTALLATION
1. Using a clean screwdriver, carefully insert
it through the control unit opening in the pump
housing and carefully move the metering sleeve
(fig. 36) downward to its lowest position on plunger.
2. Lubricate the control unit O-ring with pet­
roleum jelly and assem ble it to the control unit.
3. Holding the control unit, pin, and O-ring
assembly as shown in figure 33, with the control
unit arm horizontal and pointing toward the rear of
the pump and with the pin horizontal and the iden­
tification dot (fig. 30) up, insert the assembly into
the pump housing.
4. Rotate the control unit arm 360 degrees
after installation to determine if the pin is proper­
ly positioned in the metering sleeve slot. If it is
not, the control unit arm cannot be rotated 360
degrees.
5. Rotate the control unit bushing, which was
marked in Step 5 under "Removal," so the screw
scallops in the control unit bushing are aligned
with the holes for the retainer plate attaching
screws and the control unit bushing flange in the
FUEL DELIVERY
VALVE
*
PUMP H O U S IN G
Sec. 6M
Page 373
HYDRAULIC HEAD
ASSEM BLY
OVER FLOW
VALVE
CONTROL UNIT
COVER
CONTRO L UNIT
RETAINER PLATE
FACE GEAR
M IN G
A D V A N C E
M E C H A N ISM
T - 5 5 6 5