brake JAGUAR S TYPE 1999 1.G Powertrain Manual

V6 Engine AJ-V6/AJ28
24
J.303.1358
TORQUE CHARACTERISTICS
Top inlet manifold tuning valve
Advanced
Closed
325
D.303.1358
Side inlet manifold tuning valve
Open
Closed
Closed
ClosedOpen
Retarded
V. V. T.
175
200
225
250
275
300
125
150
2000700060005000400030001000
Engine Speed (rpm)
Brake Torque (Nm)
chambers via the rear connecting hole,
further increasing the ram effect.via the rear
connecting hole.
System Performance
The valve open/close combinations across the
engine speed range have been selected in
conjunction with the VVT system to provide an
optimised torque curve. Referring to the graph, it
can be seen that there are five states that the IMT
valves and VVT can adopt throughout the engine
speed range.

V8 EngineAJ-V6/AJ28
51
Air Induction System
Charge air is supplied to the cylinders via an air
cleaner, induction tube, throttle body, throttle
body adaptor and induction manifold.
The throttle body and system operation is
identical to that of the V6 engine.
Induction Manifold
(see illustration on page 52)
To accommodate the V8 engine in the S-TYPE
model, the throttle body is re-located and now
supplies charge air via an inlet at the top centre of
the induction manifold. The manifold is
manufactured from a plastic material and has an
integral injector air supply tube on each side with
holes for the fuel injectors, but as on the AJ27
engine, the fuel feed pipes are not incorporated
into the manifold (see Fuel System). Two stub
pipes at the top of the manifold provide vacuum
connections for the vacuum hose and the brake
servo hose.
A polypropylene covered foam noise isolation pad
fits between the manifold assembly and the block.Throttle Adaptor
The throttle body is mounted to the induction
manifold via a cast aluminium adaptor. The
throttle body adaptor provides input ports for the
evaporative emissions (top stub) and part load
breather (lower side stub) and also mounts the air
assisted injection control (AAC) valve. Input and
output ports for the side mounted AAC valve are
an integral part of the adaptor casting (the ports
do not connect to the induction airstream).
Throttle de-icing is achieved by a coolant feed
through the base of the adaptor instead of the
throttle body itself as on the V6 engine (see
cooling section).
D.303.1278
AIR INDUCTION LAYOUT
D.303.1278
Air Cleaner
Induction Tube
MAF SensorIAT Sensor
Throttle Body
Throttle Body Adaptor

V8 EngineAJ-V6/AJ28
53
J.303.1359
INDUCTION VACUUM AND AIR SUPPLY CONNECTIONS
J.303.1359
Induction and Vacuum System
Emission and vacuum connections to the
induction system are shown in the illustration
above.Variable Valve Timing (VVT)
The inlet valve timing gear is fitted with the same
continuously VVT system as is used on the AJ27
engine. Operation is as described in the ÔXJ and
XK Series 1999MY UpdateÕ Technical Guide, with
the following variations:
¥ engine management system
¥ PWM solenoid control frequency is 300Hz
¥ the use of five toothed sensor rings for cam
position feedback
Note that the use of this VVT system eliminates
the need for external EGR components.
AAI Valve Inlet
Brake Servo
Vacuum
EVAP Emissions
EVAP Valve
Vacuum Control
Part Load
Breather
IP Sensor
Vacuum
Full Load
Breather

Automatic Transmission AJ-V6/AJ28
62
D.307.321
V8 Engine Adaptor Plate
D.307.321
1. J-gate selector cable lever
2. Range switch
3. Control Module
4. Solenoid block assembly5. Filter assembly
6. Sump
7. Drain plug
Construction and Operation
The transmission housing consists of a one piece
die cast aluminium case with re-inforcement ribs
to minimise noise, vibration, and harshness
(NVH). To allow for the different physical size of
the engines, there are two transmission variants
with different overall lengths and bell housings to
match the respective engines, the V8 variant being
shorter. Different torque converters are necessary
and the V8 variant is also fitted with an adaptorplate to mate the torque converter to the larger
diameter drive plate on the V8 engine.
The main features of the transmission unit are :
¥ torque converter with a twin friction face
lock-up clutch and torsional damper
¥ geartrain consisting of three epicyclic gearsets
¥ shift elements consisting of multi-plate
clutches, brakes and one way clutches
¥ control actuators: four shift solenoids, three
variable force solenoids and a PWM 5R55N AUTOMATIC TRANSMISSION
1
3
7
6
5
24

Manual Transmission AJ-V6/AJ28
68
Clutch Pedal Assembly
The clutch pedal is mounted on a combined
assembly with the brake pedal. The clutch master
cylinder is directly actuated by the pedal and
shares a common reservoir with the brake system.
An assistor spring is fitted to the clutch pedal to
reduce the actuation load.
Operation of the pedal when in cruise control
mode activates a switch which cancels this mode.
D.307.316
CLUTCH PEDAL ASSEMBLY
D.307.316
Cruise Deactivate
Switch
Slave Cylinder
Hydraulic
Connection
Fluid from Brake
Reservoir
Clutch Master
Cylinder