Land Rover Diesel Distributor Pumps Bosch Bosch Manual

Sac-hole nozzle with cylindrical sac hole
and conical tip (6b):
This type of nozzle is used exclusively
with spray-hole lengths of 0.6 mm. The
tip’s conical shape enables the wall
thickness to be increased between the
throat radius and the nozzle-body seat
with an attending improvement of nozzle-
tip strength.Sac-hole nozzle with conical sac hole
and conical tip (Fig. 6c):
Due to the conical shape of this nozzle’s
sac hole, its volume is less than that of a
nozzle with cylindrical sac hole. The
volume is...

Seat-hole nozzle
In order to minimise the residual volume
– and therefore the HC emissions – the
start of the spray hole is located in the
seat taper, and with the nozzle closed it is
covered almost completely by the nozzle
needle. This means that there is no direct
connection between the sac hole and the
combustion chamber (Figs. 7 and 8). The
sac-hole volume here is much lower than
that of the sac-hole nozzle. Compared to
sac-hole nozzles, seat-hole nozzles have
a much lower loading limit and are...

The nozzle-holder body contains the
– Pressure pin,
– Spring, and 
– Shim.
The spring is centered in position by the
pressure pin, whereby the pressure pin is
guided by the nozzle-needle’s pressure
shaft.
The nozzle is connected to the injection
pump’s high-pressure line via the nozzle-
holder feed passage, the intermediate
element, and the nozzle-body feed pas-
sage. If required, an edge-type filter can
be installed in the nozzle holder. 
Method of operation
The nozzle-holder spring applies pres-
sure...

When strokes take place in excess of the
initial stroke, the stop sleeve lifts and both
springs have an effect upon the nozzle
needle (Fig. 10).
Method of operation
During the actual injection process, the
nozzle needle first of all opens an initial
amount so that only a small volume of
fuel is injected into the combustion
chamber. 
Along with increasing injection pressure
in the nozzle holder though, the nozzle
needle opens completely and the main
quantity is injected (Fig. 11). This 2-stage...

This necessitates a nozzle holder with
needle-motion sensor (Fig. 13) which
outputs a signal as soon as the nozzle
needle opens.
Design
When it moves, the extended pressure
pin enters the current coil. 
The degree to which it enters the coil
(overlap length “X” in Fig. 14) determines
the strength of the magnetic flux.
Method of operation
The magnetic flux in the coil changes as
a result of nozzle-needle movement and
induces a signal voltage which is propor-
tional to the needle’s speed of movement
but...

Mechanical diesel-engine speed control
(mechanical governing) registers a wide
variety of different operating statuses 
and permits high-quality A/F mixture
formation. 
The Electronic Diesel Control (EDC)
takes additional requirements into ac-
count. By applying electronic measure-
ment, highly-flexible electronic data pro-
cessing, and closed control loops with
electric actuators, it is able to process
mechanical influencing variables which it
was impossible to take into account with
the previous purely...

formation in accordance with specific
control algorithms, and outputs corre-
sponding electrical signals.
3. Actuators which convert the ECU’s 
electrical output signals into mechanical
quantities.
Components
Sensors
The positions of the accelerator and the
control collar in the injection pump are
registered by the angle sensors. These
use contacting and non-contacting
methods respectively. Engine speed and
TDC are registered by inductive sensors.
Sensors with high measuring accuracy
and long-term...

Solenoid actuator for injected- 
fuel quantity control
The solenoid actuator (rotary actuator)
engages with the control collar through 
a shaft (Fig. 4). Similar to the mechani-
cally governed fuel-injection pump, the
cutoff ports are opened or closed de-
pending upon the control collar’s posi-
tion. The injected fuel quantity can be
infinitely varied between zero and 
maximum (e.g., for cold starting). Using
an angle sensor (e.g., potentiometer),
the rotary actuator’s angle of rotation,
and thus the...

Closed control loops (Fig. 5)
Injected fuel quantity
The injected fuel quantity has a decisive
influence upon the vehicle’s starting, 
idling, power output and driveability 
characteristics, as well as upon its par-
ticulate emissions. For this reason, the
corresponding maps for start quantity,
idle, full load, accelerator-pedal charac-
teristic, smoke limitation, and pump 
characteristic, are programmed into the
ECU. The driver inputs his or her re-
quirements regarding torque or engine
speed through...

This clocked solenoid valve is used to
modulate the positioning pressure at the
timing-device piston, and this results in
the dynamic behavior being comparable
to that obtained with the mechanical
start-of-injection timing.
Because during engine overrun (with 
injection suppressed) and engine start-
ing there are either no start-of-injection
signals available, or they are inadequate,
the controller is switched off and an
open-loop-control mode is selected. The
on/off ratio for controlling the solenoid...