SsangYong Korando III (2010 year). Service manual — part 39
03-19
0000-00
HP pump pressure test
▶
Prepare a special tool for high pressure test
and clean it thoroughly to prevent foreign
materials from entering.
1.
Disconnect the high pressure fuel supply pipe
on the HP pump and install the close rail in the
tool kit.
2.
Connect the other end of the close rail to the
fuel rail for test
3.
Disconnect the return hose for HP pump and
connect the clear hose and connect its the
other end to the return port of the fuel rail for
test.
4.
Connect the digital tester connector to the
sensor connector of the fuel rail for test.
Crank the engine 2 times for 5 seconds after
removing the IMV connector and fuel rail
pressure sensor connector.
Read the pressure value displayed on the
tester display is within the specified range.
5.
6.
7.
Specification
1,050 bar or more
03-20
3. CAUTIONS FOR DI ENGINE
1) Cautions for DI Engine
This chapter describes the cautions for DI engine equipped vehicle. This includes the water separation
from engine, warning lights, symptoms when engine malfunctioning, causes and actions.
DI Engine
1.
Comparatively conventional diesel engines, DI engine controls the fuel injection and timing electrically,
delivers high power and reduces less emission.
System Safety Mode
2.
When a severe failure has been occurred in a vehicle, the system safety mode is activated to protect the
system. It reduces the driving force, restricts the engine speed (rpm) and stops engine operation. Refer
to "Diagnosis" section in this manual.
Engine CHECK Warning Lamp
3.
The Engine CHECK warning lamp on the instrument cluster comes on when the fuel or
major electronic systems of the engine are not working properly. As a result, the
engine’s power output may decrease or the engine may stall.
Water Separator Warning Lamp
4.
When the water level inside water separator in fuel filter exceeds a certain level (approx.
45 cc), this warning light comes on and buzzer sounds.
Also, the driving force of the vehicle decreases (torque reduction). If these conditions
occur, immediately drain the water from fuel filter.
03-21
0000-00
2) Cleanness
(1) Cleanness of DI engine fuel system
Cleanness of DI engine fuel system and service procedures
▶
The fuel system for DI engine consists of transfer (low pressure) line and high pressure line.
Its highest pressure reaches over 1,600 bar.
Some components in injector and HP pump are machined at the micrometer 100 μm of
preciseness.
The pressure regulation and injector operation are done by electric source from engine ECU.
Accordingly, if the internal valve is stuck due to foreign materials, injector remains open.
Even in this case, the HP pump still operates to supply high pressurized fuel. This increases the
pressure to combustion chamber (over 250 bar) and may cause fatal damage to engine.
You can compare the thickness of injector nozzle hole and hair as shown in below figure (left side). The
below figure shows the clearance between internal operating elements.
The core elements of fuel system has very high preciseness that is easily affected by dust or very small
foreign material. Therefore, make sure to keep the preliminary works and job procedures in next pages.
If not, lots of system problems and claims may arise.
Hair
Nozzle hole
Valve actuator lift - 0.028 mm
Diameter
0.04 mm
Operating
clearance
0.002 mm
Diameter
2.0 mm
03-22
(2) Di engine and its expected problems and remedies can be caused by
water in fuel
System supplement against paraffin separation
▶
In case of Diesel fuel, paraffin, one of the elements, can be separated from fuel during winter and then
can stick on the fuel filter blocking fuel flow and causing difficult starting finally. Oil companies supply
summer fuel and winter fuel by differentiating mixing ratio of kerosene and other elements by region and
season. However, above phenomenon can be happened if stations have poor facilities or sell improper
fuel for the season. In case of DI engine, purity of fuel is very important factor to keep internal
preciseness of HP pump and injector.
Accordingly, more dense mesh than conventional fuel filter is used. To prevent fuel filter internal clogging
due to paraffin separation, SYMC is using fuel line that high pressure and temperature fuel injected by
injector returns through fuel filter to have an effect of built-in heater (see fuel system).
System supplement and remedy against water in fuel
▶
As mentioned above, some gas stations supply fuel with excessive than specified water. In the
conventional IDI engine, excessive water in the fuel only causes dropping engine power or engine
hunting. However, fuel system in the DI engine consists of precise components so water in the fuel can
cause malfunctions of HP pump due to poor lubrication of pump caused by poor coating film during high
speed pumping and bacterization (under long period parking). To prevent problems can be caused by
excessive water in fuel, water separator is installed inside of fuel filter. When fuel is passing filter, water
that has relatively bigger specific gravity is accumulated on the bottom of the filter.
Water drain from water separator
▶
If water in the separator on the fuel filter exceeds a certain level, it will be supplied to HP pump with fuel,
so the engine ECU turns on warning lamp on the meter cluster and buzzer if water level is higher than a
certain level.
Due to engine layout, a customer cannot easily drain water from fuel filter directly, so if a customer
checks in to change engine oil, be sure to perform water drain from fuel filter.
Water separator
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