Cleanness Of Di Engine Fuel System And Service Procedures - SSANGYONG 2004 Rexton 2.7XDi Workshop Manual

CLEANNESS

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 1600 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 stucked 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 right side
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.
GENERAL INFORMATION
DI ENG SM - 2004.4
Valve actuator lift: 0.028 mm
Hair
Diameter: 0.40 mm
Nozzle hole
DI0A-3
Operating
clearance:
0.002 mm
Diameter:
2.0 mm
Y220_0A035
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN