compression ratio JAGUAR X308 1998 2.G Workshop Manual

The
Nivomat ride levelling system improves ride quality by al
lowing the use of softer road springs, while controlling the
effects on the suspension of a fully laden vehicle. The system uses special rear dampers in place of the normal units. There
are no other components in th e system. The ride levelling system is comple tely automatic, requiring no input from the
driver.
Ride levelling may be specified as an opti on on certain models; it is not available in north American markets. Ride levelling
and adaptive damping are mu tually exclusive options.
The Nivomat damper:
Su
pplements the load-carrying capacity of th
e road springs at high vehicle loads.
Uses road inputs to the
suspension to power the levelling function.
De

tects suspension height dire
ctly from road wheel travel.
Provi
des load-dependent spring rates; the ac
cumulator gas pressure increases with load.
Pr
ovides load-dependent damping; the fluid pressure increases with load.
Op

eration
F
ollowing an increase in vehicle loading,
the dampers adapt to maintain the height of the vehicle within its design range.
The system uses road inputs to the suspension to power the levelling action, and requires up to approximately two
kilometers of travel, following a change in load, to complete the process.
Normal movement of the suspension caus es a pumping action to occur within the damper, as a result of extension and
compression of the pump rod in the pump chamber. Hydraulic fluid is pumped from the pump cham ber into a high pressure
gas accumulator. The increase in gas pressure augments the force developed between th e vehicle axle and the body,
thereby providing lift.
It
em
De
scription
1Pi

ston rod
2Pum

p chamber
3High

pressure
gas accumulator
4Diaphragm
5Co
ntrol orifice
6Pump rod
7Low pressure gas ch

amber
8Low pressure oil

reservoir


Ride Levelling

Engine System - General Infor
mation - Engine
Description an
d Operation

The AJ26 power unit is available in 3.2 L and 4.0 L versions, and comprises:
An eight cylinder 9
0 degree 'V' config
uration liquid cooled aluminium cylinder block incorporating 'Nikasil' plated
cylinder bores.
Pi
stons of open-ended skirt design, with
two compression and one oil control ring.
Two al
uminium cylinder heads, each
incorporating two camshafts.
F
our valves per cylinder.
Al

uminium valve lifters and top mounted shims.
Vari

able valve timing (VVT) of the inlet camshafts (4.0 L normally aspirated only).
Camshaft

covers manufactured from Vinylester.
Al

uminium timing cover which accommodat
es the crankshaft front oil seal.
Sin
gle row primary and secondary chains dr
ive the camshafts of each cylinder bank.
An alu
minium bed pl
ate, incorporating iron main bearing supports, which accomm odate the oil pump pick-up,

Speed an
d load
Coo
l
ant temperature
Ti
me el
apsed from start up
Cl
osed l
oop fuelling
Determination of the vapour concentration is made by stepped opening of the EVAP valve and subsequent monitoring of the
fuelling correction. This function is performed prior to purging, so that at the onse t of purging the EVAP valve can be set to
the optimum position. Should the ECM be unable to determine the concentration before purging, a default value is
employed, which is then modified whilst purging is in progress.
When the purging process is operational th e ECM modifies the basic fuelling calculation to maintain the correct air / fuel
ratio.
Purging is inhibited during fuel cut-off and stability / traction control intervention.
Coolant Temperature Sen
sor
Th
e
sensor outputs a voltage to the ECM which decreases as temperature increases.
Cooling Fans


In response to engi
ne coolant temperat
u
re and climate control system demand, the ECM will energize the cooling fans.
Climate Control Compressor
The E
C
M will allow the compressor clutch to be engaged if th
e engine temperature and load demand are normal. Should the
driver require maximum engine powe r or the coolant temperature be high, the request will be denied.
Cranking Signal

The ECM reacts to a signal fr
om th
e Body Processor Module (BPM) when the starter motor relay is energi
zed. This signal is
used to trigger starting, fu el and ignition strategies.
Engine Speed and Cranksh
aft Position
Engine
speed and cran
k position are moni
tored by a sensor which is mounted on the cylinder block (flywheel housing)
behind the crankshaft drive plat e. It indicates rotational speed to the ECM in the form of 12 pulses per crank revolution.
Engine speed is used for synchronization of fuel an d ignition systems, as well as other functions.
Camshaft Position
The ca
mshaft position sensor is mounted at
the rear of Bank 2 cylinder head on the inlet side and provides one signal every
720 degrees of crankshaft rotation. The signal, in conjunction with the signal from the crankshaft position sensor, indicates
to the ECM that the piston of cylinder 1A is approaching TDC on the compression stroke.
Variable Valve
Timing (Where Fitted)
By energi
si
ng a solenoid to allow the pass
age of pressurized oil on each of the inle t camshaft drives, the ECM can vary by a
single stepped amount, the relati ve timing of the inlet valves.
Ign
ition
Ignit
i
on spark is produced by
individual on-plug coil units.
There are two ignition amplifiers; module #1 drives coils 1A, 2B, 3B and 4A, whilst module #2 drives coils 1B, 2A, 3A and
4B. The ECM controls the amplifiers.

CAUTI
ON: When probing connectors to take
measurements in the course of the pinpoint tests, use the adaptor kit,
part number 3548-1358-00.
• NOTE: When performing electrical voltag e or resistance tests, always use a digital multimeter (DMM) accurate to 3
decimal places, and with an up-t o-date calibration certificate. When testing resistance, always take the resistance of the
DMM leads into account.
• NOTE: Check and rectify basic faults before beginning diagnostic ro utines involving pinpoint tests.
Sy
mptom Chart
Sy

mptom
Possib
le source
Acti
on
Engine

cranks, but does not fire
Secu
rity system /Immobiliser
engaged
Thr
ottle contaminated
Harness damage


F

uel pump relay
Fue

l system
R

efer to service action S491

Contact dealer techn
ical
support for information
on security system. Chec k bulletins for throttle
cleaning procedure. For fuel pump relay circuit
tests, GO to Pinpoint Test E.
.
Check fuel pressure,


REFER to Section 310
-00
Fuel System
- Gen
eral
Informati

on
.
Chec
k for associated DTCs
. Check service actions.
Engine
cranks and fires, but will
not start
F
uel pump relay
Thr

ottle contaminated
Purge

valve
Fue

l pump
Engine coolan

t temperature
(ECT) sensor
Spark plugs
fouled
Ignition coil

failure(s)
Check f

or water ingress into
spark plug wells
HT sho
rt to ground (tracking)
check rubber boots for cracks/damage
Cyl
inder compression loss
(short-term. Refer to bulletin;
303-52)
R
efer to service action S491

F
or fuel pump relay tests,
GO to Pinpoint Test E.
.
Check bull
etins for throttle cleaning procedure. For

evaporative emissions tests,
REFER to Section 303
-1
3 Evaporative Emissions
. Chec

k fuel pressure,
REFER to Section 310
-00
Fuel System
- Ge
neral
Informati

on
.
F
or ECT sensor circuit tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
For ign
ition system,
REFER to Section 303
-07
Engine Ignition
.
Check bulletins an d service
actions.
D

ifficult to start cold
Roc
hester valve
Batt

ery
Thr

ottle contaminated
Fue

l pump
Engine coolan

t temperature
(ECT) sensor
Purge
valve
Cyl

inder compression loss
(short-term. Refer to bulletin;
303-52)
Blocked part-load breather (
service action S474)
R

efer to service action S491

F
or rochester valve tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
F
or battery information,
REFER to Section 414
-0
1 Battery, Mounting and
Cables.
Check bull
etins for throttle cleaning procedure.
Check fuel pressure,
REFER to Section 310
-00
Fuel System
- Ge
neral
Informati

on
.
F
or ECT sensor circuit tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
For evaporat
ive emissions tests,
REFER to Section 303
-1
3 Evaporative Emissions
. Check bulletins an

d
service actions.
D
ifficult to start hot
Roc
hester valve
Purge

valve
Thr

ottle contaminated
Fue

l pump
Engine coolan

t temperature
(ECT) sensor
Blocked part-load breather (
service action S474)
Injec

tor leak
F
or Rochester
valve test,
REFER to Section 303
-14 Elec
tronic Engine
Controls.
Fo
r injector leak test, REFER to technical service
bulletin, 303-39. Check fuel pressure, For evaporative emissions components,
REFER to Section 303
-1
3 Evaporative Emissions
. F

or ECT sensor tests,
REFER to Section 303
-14 Elec
tronic Engine
Controls. D

ifficult to start after hot soak
(vehicle standing after engine has
reached operating temperature)
Roc
hester valve
Thr

ottle contaminated
Purge

valve
Fue

l pump
Engine coolan

t temperature

Starting System - Starting System
Diagn
osis and Testing
I
n
spection and Verification
W
A
RNING: Make sure
the vehicle is in NEUTRAL or PARK for vehicles with au tomatic transmission, NEUTRAL for
vehicles with manual transmissi on, and apply the parking brake. Failure to foll ow this instruction may result in personal
injury.
1. 1. Verify the customer concern.
2. 2. Visually inspect for obvious signs of mechanical or electrical damage, correct fitment, etc.
Vi
sual Inspection Chart
3.
3. If an obvi
ous cause for an observed or
reported concern is found, correct th e cause (if possible) before proceeding
to the next step.
4. 4. If the concern is not visually evident, refer to the Diagnostic trouble code (DTC) index.
CAUTION: When probing connectors to take measurements in the course of the pinpoint tests, use the adaptor kit,
part number 3548-1358-00. Failure to follow this in struction may result in damage to the vehicle.
• NOTE: When performing electrical voltag e or resistance tests, always use a digital multimeter (DMM) accurate to 3
decimal places, and with an up-t o-date calibration certificate. When testing resistance, always take the resistance of the
DMM leads into account.
• NOTE: Check and rectify basic faults before beginning diagnostic ro utines involving pinpoint tests.
Sym
ptom Chart
MechanicalElectrical
Starte
r motor
Flywheel

ring gear
Engine
s
eized
Batter
y condition, state of charge
Starte

r motor
F
u
se 3 of the EMS fuse box
High
power protec ti
on module
Starter relay Ignition switc
h

W
i
ring harness(es)
Damaged, loose or corroded connector
s

Body processor module (B
PM)

Engine
C
ontrol Module (ECM)
Sy
m
ptom
(
gene r
al)
Sy
m
ptom
(specific)
Possib l
e source
Acti
o
n
No
n
-Start
Engine does
not
crankEngine s
iezed
Batt
ery and
/or
cables
Inhibitor circuit St arte
r motor
Starter relay Ignition switc
h


ECM relay Body processor
modu le
Check that
the engine turns. Check the battery condition and state

of charge. For starter motor and ca ble tests,GO to Pinpoint Test A.
. For ECM relay
tests,
REFER to Section 303
-14
Electronic Engine Controls
.
Engine
c
ranks
too fast/slow
Batt ery and
/or
cables
St arte
r motor
Cy
linder
com
pression
Check the battery con
dition
and st
ate of charge. For starter motor
and cable tests,GO to Pinpoint Test A.
. Chec
k compressions.

• NO
TE: When performing electrical voltag
e or resistance tests, always use a digital multimeter (DMM) accurate to 3
decimal places, and with an up-t o-date calibration certificate. When testing resistance, always take the resistance of the
DMM leads into account.
• NOTE: Check and rectify basic faults before beginning diagnostic ro utines involving pinpoint tests.
Sym
ptom Chart
Sy
m
ptom
Possib
l
e source
Acti
o
n
Engine
cranks, but does
not fire
Secu
rit
y system /Immobiliser
engaged
Harness Fue l
system
ECM fault

Contact deal er techni
cal support for
information on security system. Check fuel
system pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For ECM tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
Engine cranks and
fi
res, but will not
start
Fu
el pump relay
Fuel

pump
Cyl
i
nder compression loss
(short-term. Refer to bulletin; 303-52)
Engine coolan t
temperature
(ECT) sensor
Spark plugs fouled, gapp
ed
incorrectly
Ignition coil fail
ure(s)
Check f
o
r water ingress into
spark plug wells
HT sho rt to ground (tracking)
check rubber
boots for
cracks/damage
Fo
r fuel pump relay tests,
REFER to: Fuel Charging and Controls
(303
-04

Fuel Charging and Controls, Diagnosis and Testing).
Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For compression loss, REFER to the technical service bulletins. For ECT sensor tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For spark plug tests, GO to Pinpoint Test B.
.
For ign i
tion system tests, GO to Pinpoint Test
A.
.
Diff
icult to start cold
Batt
ery Fuel
pump
Cyl
i
nder compression loss
(short-term. Refer to bulletin; 303-52)
Spark plugs fouled, gapp
ed
incorrectly
F o
r battery information,
REFER to: Battery and Cables
(414
-01 Battery,

Mounting and Cables, Description and Operation).
Check fuel pressure.
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For compression loss, REFER to the technical service bulletins. For spark plug tests, GO to
Pinpoint Test B.
. For ig
nition system tests, GO
to Pinpoint Test A.
.
Diff
icult to start hot
Roc
h
ester valve
Injec
t
or leak
Purge
val
ve
Fue
l
pump
Engine coolan
t
temperature
(ECT) sensor
F or R
ochester
valve test,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For injector leak test, REFER to technical
service bulletins. Check fuel pressure. For evaporative emissions components,
REFER to: Evaporative Emissions
(303
-13
Evaporative Emissions, Diagnosis and Testing).
For ECT sensor tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
D iff
icult to start after hot soak
(vehicle standing after engine has reached operating temperature)
Roc h
ester valve
Injec
t
or leak
Purge
val
ve
Fue
l
pump
Engine coolan
t
temperature
(ECT) sensor
F or R
ochester
valve test,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For injector leak test, REFER to technical service bulletins. Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).

Diagnostic Trouble Code (D
TC) index
D
iagnostic Trouble Code (DTC) Index
DT

C
De
scription
Possib
le Source
Acti
on
P0300Ran

dom misfire detected
ECM t
o ignition coil primary circuit
faults (cylinder misfire detected
DTCs also logged)
Ignition coil
ground circuit; open
circuit, high resistance
F
uel injector circuit fault(s)
(injector DTCs also logged)
Ignition coil
failure(s)
Check f

or water ingress into spark
plug wells
HT sho
rt to ground (tracking)
check rubber boots for
cracks/damage
Spark plug
failure/fouled/incorrect
gap
Cy
linder compression low
F

uel delivery pressure (low/high)
F

uel injectors restricted/leaking
Fuel contamination


P

AS pulley bolts loose (see Service

Actions)
W
orn camshaft/broken valve
springs
For ign
ition system tests,GO
to Pinpoint Test A.
. For
inje
ctor circuit tests,
REFER to: Fuel Charging and
Controls (30
3-04 Fuel
Charging and Controls,
Description and Operation).
Check compressions. For
spark plug tests,GO to
Pinpoint Test B.
.
Check fuel
pressure,
REFER to: Fuel System
Pressure Check (31
0-00 Fuel
System - General
Information, General
Procedures).
For fuel injectors,
REFER to: Fuel Charging and
Controls (30
3-04 Fuel
Charging and Controls,
Diagnosis and Testing).
For fuel tank and lines
information,
REFER to: Fuel Tank and
Lin
es

(310-01 Fuel Tank and
Lines, Description and
Operation).
Check PAS pulley bolt torque
(REFER to technical service
bulletins). For engine
information,
REFER to: Specifications

(3
03-01 Engine,
Specifications).
P0301Misfire
detected, Cyl 1
R
EFER to possible sources for P0300
R
EFER to actions for P0300.
P0302Misfire

detected, Cyl 3
P0303Misfire

detected, Cyl 5
P0304Misfire

detected, Cyl 7
P0305Misfire

detected, Cyl 2
P0306Misfire

detected, Cyl 4
P0307Misfire

detected, Cyl 6
P0308Misfire

detected, Cyl 8
P0351Igni

tion coil primary/secondary circuit
malfunction, cyl 1
ECM to
ignition module primary
circuit open circuit, short circuit to
ground, high resistance
Igni
tion module to ignition coil
primary circuit open circuit, short
circuit to ground, high resistance
Ignition modu
le ground circuit
open circuit, hi gh resistance
Ignition coil
failure
Ignition modul

e failure
F
or ignition circuit tests,GO to

Pinpoint Test A.
.
P0352Igni
tion coil primary/secondary circuit
malfunction, cyl 3
P0353Igni
tion coil primary/secondary circuit
malfunction, cyl 5
P0354Igni
tion coil primary/secondary circuit
malfunction, cyl 7
P0355Igni
tion coil primary/secondary circuit
malfunction, cyl 2
P0356Igni
tion coil primary/secondary circuit
malfunction, cyl 4
P0357Igni
tion coil primary/secondary circuit
malfunction, cyl 6
P0358Igni
tion coil primary/secondary circuit
malfunction, cyl 8
P1313Misfire rate
catalyst damage, Right-hand
cylinders. NOTE. This DTC will flag only
when accompanied by a random or
individual cylinder misfire DTC; P0300,
R
efer to possible causes for P0300-P0308
R
efer to actions for P0300-
P0308.

CAUTIO
N: When probing connectors to take
measurements in the course of the pinpoint tests, use the adaptor kit,
part number 3548-1358-00.
• NOTE: When performing electrical voltag e or resistance tests, always use a digital multimeter (DMM) accurate to 3
decimal places, and with an up-t o-date calibration certificate. When testing resistance, always take the resistance of the
DMM leads into account.
• NOTE: Check and rectify basic faults before beginning diagnostic ro utines involving pinpoint tests.
Sym
ptom Chart
Sym

ptom
(general)
S y
mptom (specific)
Possib
l
e source
Acti
o
n
No
n
-Start
Engine
does not cran
k
Starter relay ECM relay Batt
ery Park
/Neutral
switch
Starting system

Harness damage
Engine s
iezed
Check r
e
lay dates. Check
for DTCS. For starting
system,
REFER to Section 303
-06 Sta r
ting System
.
F or ECM
relay tests, GO to Pinpoint Test
AD.
.
F o
r battery information,
REFER to Section 414
-0 1
Battery, Mounting and

Cables.
Fo r

Park/Neutral tests, GO to Pinpoint Test AC.
. Fo
r engine information,
REFER to Section 303
-01 En
gine
.
Engine cranks, but does
not fireSecurity
syst
em /Immobiliser
engaged
Thr o
ttle contaminated
Harness damage
Fu
el pump relay
Fue
l
system
R
e
fer to service action
S491
Contact dealer techni
cal
support for information
on security system. For fuel system,
REFER to Section 303
-0 4
Fuel Charging and
Controls.
Check bull etins for throttl
e cleaning procedure.
Check service actions.
Engine cranks an d
fires,
but will not start
F u
el pump relay
Thr
o
ttle contaminated
Purge
val
ve
Fue
l
pump
Engine coolan
t
temperature

(ECT) sensor
Spark plugs
fouled
Ignition coil
fail
ure(s)
Check f
o
r water ingress
into spark plug wells
HT sh o
rt to ground
(tracking) check rubber
boots for cracks/damage
Cyli
nder compression loss
(short-term. Refer to bulletin; 303-52)
Re
fer to service action
S491
Fo
r fuel pump relay tests,
REFER to Section 303
-0 4
Fuel Charging and
Controls.
. Check bulletins for throttl
e cleaning procedure.

Check fuel pressure. Refe r to Technical service
bulletins. For ECT sensor tests, GO to Pinpoint Test C.
. Fo
r ignition system,
REFER to Section 303
-07 En
gine Ignition
.
Check bulletins an d service a
ctions.
Di
f
ficult to
start
D iff
icult to start cold
Roc
h
ester valve
Batt
ery Thro
ttle contaminated
Fue
l
pump
Engine coolan
t
temperature

(ECT) sensor
Purge val
ve
Cyl
i
nder compression loss
(short-term. Refer to bulletin; 303-52)
Blocked part-load breather (s
ervice action S474)
R
e
fer to service action
S491
For R
ochester valv
e test, GO to Pinpoint Test AE.
. Fo
r battery information,
REFER to Section 414
-0 1
Battery, Mounting and

Cables.
Check bull etins for throttl
e cleaning procedure.
Check fuel pressure. For ECT sensor circuit tests,
GO to Pinpoint Test C.
. F
or evaporative
emissions tests,
REFER to Section 303
-1 3
Evaporative
Emiss
i
ons
.
R e
fer to bulletins for co
mpression information,
and service actions for part-load breather procedure and compressions.
Diff
icult to start hot
Roc
h
ester valve
Purge
val
ve
Thr
o
ttle contaminated
F
or R
ochester valv
e test, GO to Pinpoint Test AE.
. F
or evaporative emissions tests,
REFER to Section 303
-1 3
Evaporative

Refrigeration Cycle

The Compressor draws low pressure, lo
w te
mperature, refrigerant from the evaporat or and, by compression, raises the
refrigerant temperature and pressure. High pressure, hot, vaporized refr igerant enters the condenser, where it is cooled by
the flow of ambient air. A change of state occurs as the refrigerant cools in the condense r and it becomes a reduced
temperature, high pressure, liquid.
From the condenser, the liquid passes into the receiver drier which has three functions:
Storage vessel
for varying sy
stem refrigerant demand.
F
ilter to remove sy
stem contaminants.
Mo
isture removal via the dessicant.
With the passage through the receiver drie r completed, the liquid refrigerant, still at high pressure, enters the expansion
valve where it is metered through a contro lled orifice, which has the effect of reducing the pres sure and temperature. The
refrigerant, now in a cold atomized st ate, flows into the evaporator and cools the air passing through the matrix.
As heat is absorbed by the refrigerant, it once again changes state, into a vapor, and returns to the compressor for the
cycle to be repeated.
An automatic safety valve is incorporated in the compressor, which will operate if the system pressure rises above 41 bar.
The valve will reseat when the pressure drops below 27,6 bar.
It
em
Par
t Number
De
scription
1—Compre

ssor
2—Conden

ser
3—Re

ceiver drier
4—Expans

ion valve
5—Evaporator


6—4

-level pressure switch


The terms 'high' and 'low'

pressure (or si
de) refer to the pres sure differential betw een the compressor and expansion valve
ports. This differential is critical to sy stem fault diagnosis and efficiency checks.