Fuel Injection Timing Check - Mitsubishi S4Q User Manual

FUEL INJECTION TIMING CHECK

Figure 163 Finding top dead center on compression
stroke
Delivery
Delivery valve
valve
Seat
surface
Relief valve
Delivery valve
Figure 164 Checking injection timing (1) (Removing
delivery valve)
Figure 165 Checking injection timing (2)
98 / 174
holder
Spring
FUEL SYSTEM
19 FUEL INJECTION
TIMING CHECK
The injection timing varies according to the output, rpm
and specifications of the engine. Be sure to verify the
timing by referring to the specifications.
1. Bringing the No.1 cylinder piston to the top dead
center on compression stroke
1) Put socket (30691–21800) on the crankshaft
pulley nut and turn the crankshaft in the
normal direction (clockwise as seen from the
front end).
2) Stop turning the crankshaft when the timing
mark "0" on the crankshaft pulley is aligned
with the pointer.
3) Push down on the inlet and exhaust valve
rocker arms for the No.1 cylinder to make sure
they are not being pushed up by the pushrods
(the inlet and exhaust valves have some
clearance).
2. Checking injection timing
1) Remove delivery valve holder from the No.1
plunger of the injection pump. Remove
delivery valve and spring from the holder,
restore the holder to the pump.
2) Connect a spare injection pipe to the No.1
plunger, with its free end held downward so
that you can observe the fuel flow from that
end.
3) Turn the crankshaft to bring the No.1 piston to
60° position before top dead center on
compression stroke.
4) While operating the priming pump to allow the
fuel to flow from the injection pipe, slowly turn
the crankshaft in the normal direction. Stop
turning the crankshaft when the fuel flow
stops.
5) Make sure the timing mark on the crankshaft
pulley is aligned with the pointer.
ENGLISH Service Manual Mitsubishi SQ-Series diesel engines
FUEL SYSTEM
Version 08/2004