User Manual

Chapter 13
BOSCH HDI EDC 15C2 INJECTION SYSTEM AND PARTICLE FILTER
124
E - EFFECTS ON ENGINE OPERATION
At constant engine load and speed, post-injection leads to an increase in engine
torque.
To maintain the same driving pleasure and avoid engine hesitation during post-
injection, the injection ECU program incorporates the following strategies:
• reduction of the main injection flow,
• turbocharging pressure regulation.
1 - Reduction of the main injection flow
SDI045D
N
K
j
k l
m
n
K - Time (s)
N - Cylinder pressure (bar)
j - Pre-injection
k - Main injection
l - Post-injection
m - Reduction in main injection time
n - Reduction in cylinder pressure
Reducing the main injection flow cancels out the increase in torque due to post-
injection.
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