Yanmar 3TNV82A Service Manual page 252

FUEL SYSTEM
2. Visually inspect the fuel injectors and nozzle
protectors for deposits or damage. Clean, repair
or replace as necessary.
Note: Test the fuel injector using an injection
nozzle tester. Operate the tester
following the information provided by the
tester manufacturer. Use clean, filtered
fuel or FIE calibration fluid for the test.
3. Using the correct adapter, connect a fuel
injector to a nozzle tester. Aim the fuel injector
into a suitable container to catch the fuel spray.
A
WARNING
• Never inject fuel toward you. Since the
fuel is injected at high pressure from
the nozzle, it may penetrate the skin,
resulting in injury.
• Never inject fuel toward a fire source.
Atomized fuel is highly flammable and
may cause a fire or burn skin.
A
CAUTION
FLYING OBJECT HAZARD!
• ALWAYS wear eye protection when
servicing the engine and when using
compressed air or high-pressure
water. Dust, flying debris, compressed
air, pressurized water or steam may
injure your eyes.
• Failure to comply may result in minor
or moderate injury.
7-34
4. Pump the operating lever of the tester slowly,
observing the pressure reading at the point
where the fuel injector begins spraying fuel
(Figure 7-48).
See Figure 7-51 for injector ID location.
See Test and Adjustment Specifications on
page 7-8 for correct pressure readings.
Note: The opening pressure of a new fuel
injector will be approximately 725 psi
(5 MPa; 51 kgf/cm
0000028en
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 it for 5 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.
0000003en
Fuel Injectors
Figure 7-48
2
) higher than one that
TNV DI Service Manual