SsangYong Actyon Sports II. Manual — part 24

03-16

Dynamic test for backleak of injector

▶

Warm up the engine so that the engine
coolant temperature be over 80℃ and star

the engine again.

Disconnect the injector return hose and cover

the openings with caps shaped screw

(included in the special tool)..

1.

2.

Connect the hose of the container for

measuring backleak to the return nipple of the

injector.

Start the engine again and let the engine idle

for 30 seconds.

Perform backleak test of fuel system with a

diagnostic device after 30 seconds.

3.

4.

5.

This test consists of 4 cycles, and the engine rpm

reaches 3,500 rpm for 18 seconds in each cycle.

Check the amount of backleak collected into

the container and confirm that it is within the

specified range.

6.

Specification

38 ml or less

03-17

2210-01

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

5.

6.

7.

Specification

1,050 bar or more

03-18

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.

03-19

2210-01

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 1,800 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