Ford Transit 2002 Owner's Manual page 869

control valve is slightly above atmospheric pressure during engine run conditions.
Fuel pressure in the injector needle upper chamber and injector needle lower chamber is
equal to the high-pressure fuel feed pressure. The injector needle is held in the closed
position by the injector needle control spring.
Fuel injector working state opening
Item Part Number
1 -
2 -
3 -
4 -
5 -
6 -
7 -
The fuel injection process starts with a voltage being applied to the solenoid valve with a
pull-in current of 12 amperes.
The solenoid valve moves the injection control valve against the pressure of the injection
control valve spring.
The injection control valve releases the high fuel pressure from the injector needle upper
chamber and vents the excess pressure out through the fuel injector fuel return bore. The
fuel pressure does not drop instantly but is slowed down by the injector needle upper
control chamber fuel outlet choke.
High-pressure fuel entering the injector needle upper chamber and the injection control
valve chambers is restricted by the very small diameters of the injector needle upper
chamber fuel inlet choke and the control chamber inlet choke.
Fuel injector working state injecting
Description
Solenoid valve
Fuel injector fuel return bore
Injection control valve
Injector needle upper control chamber fuel outlet choke
Injector needle upper chamber
Injector needle upper chamber fuel inlet choke
Control chamber fuel inlet choke
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