Mitsubishi S4Q User Manual page 103

FUEL SYSTEM
Good nozzles
(reusable)
Figure 172 Possible spray pattern
Figure 173 Washing nozzle tip
Service Manual Mitsubishi SQ-Series diesel engines
Version 08/2004
Bad nozzles (recondition or
replace if necessary)
Needle
valve
Body
FUEL INJECTION NOZZLES
2. Spray pattern
1) Operate the tester handle at a speed of one
stroke per second and look at the spray
pattern (shape of discharge) when fluid begins
to flow through the fuel injection nozzle. The
discharge must be 0°. Any change is an
indication of a bad nozzle.
2) If the nozzle is bad, loosen the retaining nut
and remove the tip from the nozzle. Wash the
tip — needle valve and body — in clean diesel
fuel. After washing, put the needle valve in the
body in clean diesel fuel.
CAUTION
Be careful not to cause damage to the tip when
removing it from the nozzle body.
3) After cleaning the nozzle tip, install it to the
nozzle body and tighten the retaining nut to
the specified torque.
Tightening torque
4) If the discharge pattern (nozzle) is still bad
after the nozzle tip has been washed, replace
the tip.
NOTE
a Do not touch the sliding surface of the
needle valve.
b When installing a new nozzle tip, remove
resin film from the tip and slide the needle
valve in the body in clean diesel fuel to wash
off inhibitor completely.
ENGLISH
37 ± 2.5 N·m
(3.77 ± 0.25 kgf·m)
[27 ± 1.8 lbf·ft]
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