
1.3 MULTIJET 16V
(75 & 90 HP)
FIAT PUNTO TRAINING OUTLINE
Fiat Auto S.p.A.
After Sales Training
Multiple injection
The multiple injection operation strategy makes it possible to accurately control the
combustion process within the cylinder. Injections are modulated so as to avoid too high
pressure gradients, which would cause the combustion noise to increase and the mechanic
components to be stressed unnecessarily.
Multiple injections make it possible to reduce the pollutants to a significant extent while
ensuring optimum engine performance. The engine management control unit can perform up
to 5 injections per engine cycle, which are referred to as follows:
- PILOT injection
- PRE injection
- MAIN injection
- AFTER injection
- POST injection.
Injection
Combustion
factor
T.D.C.
Four work areas can be identified in this application:
1 PILOT inj PRE + MAIN
2 PRE inj MAIN
3 PILOT inj PRE + MAIN (with dwell time between PILOT and PRE > 1000 usec.)
4 MAIN injection
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