Ford 6.4L Power Stroke - Pre-Main Injection; Stages of Injection

47
Two Stages of Injection
• Main Injection
• End of Main Injection
89
Fuel ManageMent SySteM
90
Stages of Injection
• The injection cycle has two (2) stages.
• Main injection.
• End of main injection.
• This injection system is capable of performing both steps
of the injection cycle up to 5 times per firing cycle.
Pre-Main Injection
• The piezo electric fuel injector is constantly being filled
with fuel via the high pressure fuel injection pump.
• High pressure fuel from the high pressure fuel
injection pump enters the following areas:
- control piston chamber (2).
- spring side of the valve mushroom (4).
- high pressure chamber (3).
• The needle control spring (9) holds the needle on its seat
so that fuel cannot enter the combustion chamber.
• The piezo actuator (1) is in a non-energized state.
1
2
4
3
9