Needle Lift Sender - Volkswagen Marine TDI 100-5 User Manual

Engine electronic systems

Needle lift sender

The needle lift sender is located on the injection
th
nozzle of the 5 cylinder.
It signals the actual start of injection to the
engine control unit. The signal is used to ensure
the characteristic map for start of injection is
adhered to.
Functional description
The voltage applied at the magnet coil of the
needle lift sender is controlled by the engine
control unit such that a constant current always
flows. In this way, a magnetic field is generated
in the magnet coil (solenoid). The magnetic field
changes with the movement of the nozzle needle
that is connected to the thrust pin. The change
distorts the applied voltage; a pulse peak is
created. The engine control unit calculates the
actual start of injection from the time difference
between the pulse peak and the TDC signal from
the engine speed sender. The actual start of
injection is compared with the set start of
injection specified in the characteristic map of the
engine control unit and is corrected by the
control unit in the event of deviations.
Substitute function
An emergency operation program is started in
the event of the needle lift sender failing.
The start of injection is controlled according to
fixed setpoints from the characteristic map. In
addition, the injection volume is reduced.
Effect
The power output of the engine is reduced.
Superior 28 Technology
Nozzle holder
Magnet coil
Thrust
pin
MSSP_001_018