Land Rover Lesson 2 Auto Trans Coolingine Rover Manual

							Pressure Control Valve (PCV)The PCV is located on the HPP. It governs the fuel
pressure at the HP outlet of the HPP and thus, the fuel
pressure within the rail. In addition, the PCV dampens
the fluctuations in the pressure, which occur during the
delivery of fuel through the HPP and through the
injection process.
The PCV ensures that optimum pressure exists in the
rail for every operating condition of the engine.
The PCV is an electro-magnetically operated valve with
spring support.
The electrical current supplied by the ECM through the
solenoid pulls back the control pin. This allows the
diesel fuel to pass the ball valve and thus the fuel flow
into the common rails.
The entire armature is coated with fuel for lubrication
and cooling.
NOTE: The PCV cannot be replaced as a separate
component in service.
Fuel Charging and ControlsLesson 2 – Powertrain
157Technical Training (G421108) 
						

							PCV non-controlledA
PCV controlledB
Fuel from the HPP1
To fuel return2
Ball valve3
Compression spring4
Armature5
Coil energised6
Control pin7
High pressure fuel8
Control current9
Characteristic of the PCV10
PCV Non-controlled (A)
The ball valve (3) will only be operated through the
force exerted upon it by the spring (4). Thereby, the
PCV is classed as open.
PCV Controlled (B)
The current flowing through the solenoid (6) draws the
pin (7) down. This in turn transfers the magnetic force
via the pin to the ball valve (3). The pull of the pin, and
the pressure on the ball valve, is proportional to the
valve flow (9).
(G421108) Technical Training158
Lesson 2 – PowertrainFuel Charging and Controls 
						

							HP Common Fuel Rails
The fuel rails are manufactured from forged steel. They
store the fuel at high pressure and prevent pressure
fluctuations in the HP system.
All HP pipes have an internal diameter of 2.5mm except
the pipes to the injectors, which are 3.0mm. Total rail
volume is 33cc.
Fuel Charging and ControlsLesson 2 – Powertrain
159Technical Training (G421108) 
						

							FUEL INJECTORS
Harness connection1
HP connection2
Control piston3
Nozzle needle4
Nozzle HP chamber5
Nozzle spray holes6
Valve mushroom7
Fuel return8
Valve piston9
Piezo actuator10
The fuel injectors are operated directly by the ECM for
fuel metering (start of injection and quantity of fuel
injected).
The operating components of the piezo fuel injectors
are:
•The piezo actuator
•The injector body containing the hydraulic servo
system
•The fuel injector nozzle
NOTE: New injectors can be installed in any cylinder
and DO NOT have to be configured.
NOTE: Each Injection event is controlled by a charge
and discharge cycle allowing energy to dissipate in, and
recover from, the injector. Never disconnect the wiring
connector when the vehicle is running. The injector may
remain open thus causing engine damage.
NOTE: For safety reasons, the engine must be at
standstill for 30 seconds before starting work on the HP
fuel systems.
(G421108) Technical Training160
Lesson 2 – PowertrainFuel Charging and Controls 
						

							Fuel Injector Not Actuated (Not Injecting Fuel)
Piezo actuator1
HP connection2
Hydraulic force applied on control piston3
Hydraulic force acting on tip of nozzle4
Control piston5
Fuel return6
Fuel return7
Control piston8
Nozzle needle9
High pressure chamber of nozzle10
Control chamber11
Valve mushroom12
The HP fuel from the fuel-rail passes through the HP
connection (2) into the control chamber (11) and into
the HP chamber (10) of the fuel injector nozzle.
The piezo actuator (1) is currentless and the valve
mushroom (12) closes the bore to the fuel return (7) by
means of spring pressure.
There is how ever a continuous fuel return (6) to vent
internal leakage within the injector.
The hydraulic force (3), which is now applied on the
control piston by the fuel under high pressure in the
control chamber (11) through the control piston (8), is
greater than the hydraulic force (4) acting on the tip of
the nozzle (since the area of the control piston in the
control chamber is greater than the area of the tip of the
nozzle).
Fuel Charging and ControlsLesson 2 – Powertrain
161Technical Training (G421108) 
						

							Fuel Injector Actuated (Injecting Fuel)
High pressure supply1
Valve piston2
Hydraulic force applied on control piston3
Hydraulic force acting on tip of nozzle4
Control piston5
Fuel return6
Piezo actuator7
Fuel return8
Valve piston9
Valve mushroom10
Control chamber11
Control piston12
Nozzle needle13
The piezo actuator (7) energized by the ECM extends
(charging phase) and presses on the valve piston (9).
The valve mushroom (10) opens the bore, which
connects the control chamber (11) to the fuel return (8
then 6).
As a result, the pressure in the control chamber drops,
and the hydraulic force (4) acting on the tip of the nozzle
needle is now greater than the force (3) acting on the
control piston in the control chamber.
The nozzle needle (13) moves upwards and the fuel
passes through the six spray holes into the combustion
chamber.
(G421108) Technical Training162
Lesson 2 – PowertrainFuel Charging and Controls 
						

							Engine Starting
During starting, the fuel rail pressure must be at least
150 bar. Should the pressure be below this figure, the
injectors will not operate, resulting in the vehicle not
starting.
Engine Stopped
To stop the engine the ECM stops energising the piezo
actuators, therefore, no fuel is injected and the engine
speed drops to zero.
Fuel Charging and ControlsLesson 2 – Powertrain
163Technical Training (G421108) 
						

							Fuel Delivery System Component Location
Filler cap and lanyard1
Breather line Y piece to charcoal canister2
Charcoal canister purge line3
Charcoal canister4
(G421196) Technical Training344
Lesson 2 – PowertrainFuel Tank and Lines 
						

							Rear differential breather pipe5
Tank breather pipe6
Mounting screw (6 off)7
Heat shield8
Cover9
Pipe - Fuel pump to engine (feed)10
Pipe - EVAP purge valve to charcoal canister11
DMTL pump (NAS only)12
DMTL filter (NAS only)13
Fuel tank14
Fuel pump module assembly15
Tank breather pipe16
Fuel filler pipe17
Charcoal canister vent pipe18
Cradle19
GENERAL
The major components of the 4.4L V8 fuel system
comprise a fuel tank, a fuel pump, a fuel filler assembly
and two fuel level sensors.
The 4.4L V8 fuel system uses a fuel pump mounted in
the fuel tank to deliver a uniform level of pressure to
the fuel rails which supply fuel to all fuel injectors. The
fuel rails and the injectors are described in Fuel &
Charging Controls – 4.4L V8.
Fuel system emission control is described in Engine
Emission Control - 4.4L V8
Fuel Tank and LinesLesson 2 – Powertrain
345Technical Training (G421196) 
						

							FUEL TANK ASSEMBLY
Pipe - purge valve to charcoal canister1
Tank breather pipe2
Fuel pump module flange3
Pump module clamp4
Pump module collar5
Pump module seal6
Cover7
Pipe connection - purge valve8
Pipe connection - fuel feed9
Cradle10
Fuel tank11
Pipe - fuel feed12
Mounting screws (6 off)13
Fuel filler hose14
Heat shield15
Scrivet16
Screw M617
Clip cover18
The fuel tank is located on the right hand side of the
vehicle, between the transmission and the right hand
chassis longitudinal. The tank is located on a mounting
cradle which secures the whole fuel tank assembly to
the vehicle. The tank has a useable capacity of 86.3
litres (22.8 US gallons).
The cradle is attached to the chassis with six screws.
When the cradle is attached to the chassis, the tank is
positively secured via foam pads which bear against the
central chassis cross beam. A protective cover is fitted
to the front right hand corner of the tank and provides
additional protection.
(G421196) Technical Training346
Lesson 2 – PowertrainFuel Tank and Lines