GMC 4000 Series Service Manual page 373

Sec. 6M
Page 362
FUEL INJECTION SYSTEM— TORO-FLOW ENGINE
4. Remove the small hex bleeder plug (3, fig.
9) from the top of the secondary filter which has
been suspended.
5. Pour clean fuel into the filter through the
plug hole opening and observe the overflow valve
at the injection pump for presence of fuel.
NOTE: If fuel does not flow from the overflow
valve threads, and the secondary filter is full of
fuel, loosen the overflow valve several more turns.
6. When a clear stream of fuel flows from
around the overflow valve threads at the injection
pump, tighten the valve and connect the lines which
were removed.
7. Continue to pour fuel into the secondary fil­
ter until full, then install hex bleed plug in filter.
NOTE: DO NOT ATTEMPT TO REMOUNT
FILTER AT THIS TIME.
8. Remove bowl from primary filter and fill
completely with clean fuel. Reinstall bowl to filter.
9. Disconnect line at top of secondary filter
and slowly fill the line with fuel. When the line is
full, reconnect it to the filter.
10. Start and operate engine for a few minutes,
then shut it off and try to restart.
NOTE: If engine still will not start, repeat
foregoing steps 1 through 9.
11. After starting the engine, lower the second­
ary filter into position at engine. Secure all items
which were detached.
1 Injection Pump Assy
2 Lock Wire
3 Face Gear
4 Mark on Face Gear
5 Mark on Ledge
Figure 10— Timing Marks at Face Gear and at
Injection Pum p Gear Flange
G M C S E R V I C E M A N U A L
6 Pump Driven Gear
7 Pump Drive Hub
8 Pointer (In Pump Body)
9 Mark on Drive Hub
10 Engine Front Cover
T-705-1
INJECTION TIMING
The fuel injection pump assembly is timed to
the engine when pump assembly is installed, and
should not require any subsequent alteration if the
installation is done properly. Refer to "Fuel In­
jection Pump Replacement" later in this section
for pump installation instructions.
In the event there is reason to suspect that
fuel injection is not properly timed, the following
procedure is necessary to check the timing.
CHECKING INJECTION TIMING
(WITH ALL FUEL UNITS INSTALLED)
1. Remove the cover and gasket from right
side of fuel injection pump to expose the alignment
marks in the opening below the control unit lever
(4 and 5, fig. 10).
2. Remove the access cover and gasket from
top of engine front cover assembly to expose point­
er (8, fig. 10) and mark on injection pump hub (9,
fig. 10).
SUGGESTION: To prevent accidental dropping
of bolts, washers, etc., into engine front cover and
out of reach, put clean shop cloth into cavity below
the gear attaching bolts. DO NOT CRANK ENGINE
UNTIL THE CLOTH HAS BEEN REMOVED.
3. Remove rocker arm cover from left-hand
cylinder head, then crank engine to place No. 1
piston on compression stroke - (both valves will
then be closed and push rods can be turned with
fingers). Slowly crank the engine until the "INJ"
Figure 11— Tim ing M a rk s at Crankshaft D a m p e r