GMC 4000 Series Service Manual page 375

Sec. 6M
Page 364
FUEL INJECTION SYSTEM— TORO-FLOW ENGINE
T
EWDRIVER
A CLEARANCE SHOULD EXIST HERE.
- *
L _ _ >
I s
f EXCESS FUEL'
STARTING DEVICE
STOP PLATE
HOLD LEVER FORWARD
HIGH SPEED SCREW
Figure 14— Checking for Clearance Between
Cam Nose and Stop Plate
NOTE: If the two screws attaching the excess
fuel starting device are loosened, or the excess
fuel starting device is removed or replaced, the
injection pump will be out of calibration. It will
then be necessary to remove pump for recalibra­
tion.
2. While holding operating lever (fig. 14) in
"IDLE" position, and stop plate (fig. 14) to rear of
engine against spring tension of excess fuel start­
ing device, check to see if there is clearance be­
tween cam nose and stop plate. If there is no clear­
ance, back out idle adjusting screw (fig. 14) just
to obtain clearance before making spring pack
adjustment.
1 Supply Pump
2 Outer Spring Guide
3 Outer Spring
4 Outer Spring Spacer
Figure 15— G overnor Spring a nd Spacer A rrangem ent
G M C S E R V I C E M A N U A L
IF NOT, BACK OUT IDLE
SPEED SCREW AS
.REQUIRED
CAM N O SE
IDLE SPEED
^ SC R E W
5 Inner Spring Guide
6 Inner Spring Spacer
7 Inner Spring
8 Governor Sleeve
T-2375
NOTE: It is possible in Step 2 previously,
where engine idle is set to "Specifications," engine
running and the cam nose touches the stop plate
that a malfunction exists in the hydraulic head a s ­
sembly.
3. Disconnect inlet and outlet fuel lines from
rear of fuel pump and plug or cap the line openings
to prevent dirt from entering.
4. Remove fuel supply pump as explained later
under "Fuel Supply Pump Repair and Replacement"
(fig. 35). Remove inner and outer governor springs
and adjusting spacers (noting the position of spac­
ers and spring guides). Figure 15 shows spacer and
guide locations. The inner spring (7, fig. 15) is the
high speed spring and must have a gap. The outer
spring (3, fig. 15) is the low speed spring and must
be precom pressed. Determine the proper shim
pack behind the governor springs with supply pump
gasket in place as follows:
IMPORTANT: The flat (2, fig. 35) on the fuel
pump drive shaft must engage with the gear in the
supply pump. E xercise care with seal (9, fig. 35).
5. Position governor sleeve assem bly in for­
ward position as shown in figure 16. Then, place a
quantity of adjusting spacers (6, fig. 15) between
inner spring and the spring guide (5, fig. 15), so
that when supply pump with gasket is held in in­
stalled position (flush with governor housing),
inner spring can be turned but has no end play.
This can be checked with a finger through governor
cover opening (fig. 16). When this condition exists,
remove supply pump and remove adjusting spacers
to obtain proper gap of 0.089 to 0.108 inch.
1 Inner (High Speed)
Spring
2 F ulcrum L ever A ssy .
3 G overnor Housing
4 E x cess Fuel Starting
D ev ice
Figure 16— View of Governor M echanism
Through Cover
5 Control Rod
6 Governor S leev e
7 Outer (Low Speed)
Spring
8 Outer Spring Guide
O pening