Mitsubishi S4Q, User Manual

Page: 102 / 174

102 / 174 Service Manual Mitsubishi SQ-Series diesel engines
Version 08/2004
ENGLISH
FUEL INJECTION NOZZLES FUEL SYSTEM
21.2 Testing
1. Injection pressure (valve opening pressure)
1) Install the injection nozzle on the tester. Slowly
operate the tester handle full strokes to bleed
(remove) air from the pipe and nozzle.
2) Make a slow increase in pressure by
operating the tester handle at a speed of more
than one stroke per second while observing
the pressure gage.
3) The pressure gage reading will slowly
increase and, when the nozzle starts
discharging fuel, it will go down fast. Take the
gage reading right then as the injection
pressure.
Unit: MPa (kgf/cm
2
) [psi]
4) If the injection pressure is not correct, make
an adjustment of the nozzle by adding or
removing the shims inside the nozzle holder.
Figure 170 Testing fuel injection nozzle
Item Assembly Standard
Injection pressure
14.22
(145 )
[2063 ]
CAUTION
When testing the injection nozzle, keep its tip pointed
away from the operator. Fuel from the orifices in the
tip of the nozzle is under high pressure and can
cause injury to the operator.
+0.78
0
+8
0
+113
0
Figure 171 Removing nozzle tip