FUEL SYSTEM
7-24
TNV IDI Service Manual
Fuel Injectors
WARNING
HIGH-PRESSURE HAZARD!
• Avoid skin contact with the
high-pressure diesel fuel spray
caused by a fuel system leak such
as a broken fuel injection line.
High-pressure fuel can penetrate
your skin and result in serious
injury. If you are exposed to high-
pressure fuel spray, obtain
prompt medical treatment.
• NEVER check for a fuel leak with your hands.
ALWAYS use a piece of wood or cardboard.
Have your authorized Yanmar industrial
engine dealer or distributor repair the
damage.
• Failure to comply could result in death or
serious injury.
WARNING
To prevent possible eye injury,
always wear SAFETY GLASSES
while servicing the engine.
4. Pump the operating lever of the tester slowly,
observing the pressure reading at the point
where the fuel injector begins spraying fuel.
See Test and Adjustment Specifications on
page 7-6 for correct pressure readings.
Note: Opening pressure of a new fuel injector
will be approximately 72.5 psi (0.5 MPa;
5 kgf/cm
2
) higher than one that has been
operated for five hours or longer.
5. Pump the operating lever slowly to hold the
pressure steady at a point just below the
opening pressure and hold that pressure for five
seconds. Observe the injector to see that it is
sealing properly and is not “dripping.” If fuel
leaks from the return line fitting, check that the
nozzle case nut is tight. Service or replace the
injector if fuel continues to leak from either the
return line fitting or nozzle.
6. Pump the operating lever more rapidly to
repeatedly “pop” the injector and observe the
spray pattern. The pattern should be a very fine
uniform spray. If dripping or an uneven pattern
is seen, service or replace the injector.
Fuel Injector Test Results on page 7-25
.
TNV_IDI_ServiceManual_A4.book 24 ページ 2012年2月24日 金曜日 午前10時24分