Page 763 - Foton Workshop Manual - Auman EST-M

Engine section – Engine (Cummins ISF3.8) EG - 247

Engine control system IN

Engine control system DI
Overview

1. Instruction EG
The fuel injection system of Cummins ISF3.8 diesel engine adopts the electrical common rail fuel injection
system which mainly consists of high pressure oil pump, high pressure oil rail, injector, low pressure oil way,
TR
etc. The electric control common rail fuel injection system is used to meet stricter emission or noise
requirements and achieve lower fuel consumption rate by adopting higher fuel injection pressure, accurate
AX
injection rate and injection capacity.
2. The use range of the fuel injection system
FR
The fuel injection system is used to inject an appropriate amount of high-pressure fuel into combustion
chamber at appropriate time, while ECM adjusts its fuel injection capacity automatically as per engine load to
ensure stable running of engine. ST
3. High pressure common rail concept

a. High pressure common rail means several injectors share one high-pressure rail. The pressure in the rail is BR
established by the high pressure pump, which is up to 160MPa.
b. The injection system eliminates the interplay between the pressure and fuel injection in the traditional oil BW
supply system. The injection pressure will not be impacted by the engine speed and the injection quantity The
high pressure fuel produced by the high pressure pump is stored in the high pressure common rail and is ready
EL
for injection at any time
c. Injection quantity, pressure and timing can be separately controlled according to the needs, which
thoroughly eliminates the impact of engine speed, circulating oil supply quantity, etc. In the meanwhile, up to
5 times multi-sectional injection can be realized, which makes the injection frequency more ideal
d. The work of common rail fuel injection system of diesel engine is fully controlled by ECM. ECM
determines the engine operating status according to the engine speed, vehicle speed, fuel rail pressure, boost
intake pressure, intake temperature, coolant temperature, fuel temperature, intake quantity and throttle
position (i.e. driver’s requirement) so as to accurately measure the fuel injection quantity and control the
injection moment, time and pressure
e. Comparing with the traditional diesel engine, the high pressure common rail electric system provide ideal
air/fuel mixing ratio for the engine. It improves greatly the noise, comfort, dynamic, emission, etc.

f. The system has failure diagnosis and protective function, which optimizes the engine performance and
improves the life of engine

EG-247