1998 JAGUAR X308 valve

Engine Co
oling - Thermostat Housing
Cover4.0L NA V8 - AJ27/3.2L NA V8
- AJ26
Re
moval and Installation
Remov

al
Installation
1. O
pen the engine compartment and fit paintwork protection
sheets.
2. Drain the radiator. Refer to Ge neral Procedures. Retain the
coolant drain tray in position to catch any spillage when
removing the thermostat cover.
3. Remove the engine cove r panels for access.

4. Di
sconnect the radiator bott
om hose from the thermostat
cover.
1. Release and reposition th e hose clip, and disconnect
the bottom hose from th e thermostat cover.

5. R
emove the thermostat cover.
1. Remove the three bolts which secure the thermostat cover to the housing.
2. Remove the thermostat cover from the housing.

6. R
emove the thermostat from the housing.
1. Remove the thermostat from the housing.
2. Remove (and discard) th e seal from the thermostat.
Fit a new seal to the
thermost
at. The seal may be fitted
either way round.
1. Installation is th e reverse of the re moval procedure.
2. Fit the thermostat so that the vent ball valve locates in the
recess in the cover.
3. Tighten the thermostat cover bolts to 8-10 Nm.

Engine Cooling - Thermostat Housing Cover4.
0L SC V8 - AJ26
Re
moval and Installation
Remov

al
Installation

1.
O
pen the engine compartment and fit paintwork protection
sheets.
2. Drain the radiator. Refer to Ge neral Procedures. Retain the
coolant drain tray in position to catch any spillage when
removing the outlet pipe.

3. Di
sconnect the bottom hose
from the coolant outlet pipe.
1. Release and reposi tion the hose clip.
2. Disconnect the bottom hose.

4. R
emove the thermostat from the outlet pipe.
1. Remove the three bolts which secure the thermostat cover to the outlet pipe.
2. Remove the thermostat cover, the thermostat and
the seal from the outlet pipe. Discard the seal.
1. Installation is th e reverse of the re moval procedure.
Use new
sealing rings on th
e coolant outlet pipe and
thermostat housing.
The t
hermostat ball valve must
locate in the recess in the
cover.
2. Tighten the thermostat cover bolts to 8-10 Nm.
3. Refill the cooling system as de scribed in General Procedures.

Engine Cooli
ng - Thermostat Housing
Cover Seal4.0L NA V8 - AJ27/3.2L
NA V8 - AJ26
Re mo
val and Installation
Remova

l
Installation
1. Op
en the engine compartment and fit paintwork protection
sheets.
2. Drain the radiator. Refer to Ge neral Procedures. Retain the
coolant drain tray in position to catch any spillage when
removing the thermostat cover.
3. Remove the engine cove r panels for access.

4. Disc
onnect the radiator bott
om hose from the thermostat
cover.
1. Release and reposition th e hose clip, and disconnect
the bottom hose from th e thermostat cover.

5. Re
move the thermostat cover.
1. Remove the three bolts which secure the thermostat cover to the housing.
2. Remove the thermostat cover from the housing.

6. Re
move the thermostat from the housing.
1. Remove the thermostat from the housing.
2. Remove (and discard) th e seal from the thermostat.
Fit a new seal to the
thermostat. Th
e seal may be fitted
either way round.
1. Installation is th e reverse of the re moval procedure.
2. Fit the thermostat so that the vent ball valve locates in the
recess in the cover.
3. Tighten the thermostat cover bolts to 8-10 Nm.

Engine Cooli
ng - Thermostat Housin
g Cover Seal4.0L SC V8 - AJ26
Remo
val and Installation
Remov
a
l
Installation

1.
Op
en the engine compartment and fit paintwork protection
sheets.
2. Drain the radiator. Refer to Ge neral Procedures. Retain the
coolant drain tray in position to catch any spillage when
removing the outlet pipe.

3. Disc
onnect the bottom hose
from the coolant outlet pipe.
1. Release and reposi tion the hose clip.
2. Disconnect the bottom hose.

4. Re
move the thermostat from the outlet pipe.
1. Remove the three bolts which secure the thermostat cover to the outlet pipe.
2. Remove the thermostat cover, the thermostat and
the seal from the outlet pipe. Discard the seal.
1. Installation is th e reverse of the re moval procedure.
Use new seali
ng rings on th
e coolant outlet pipe and
thermostat housing.
The t he
rmostat ball valve must
locate in the recess in the
cover.
2. Tighten the thermostat cover bolts to 8-10 Nm.
3. Refill the cooling system as de scribed in General Procedures.

Fuel Char
ging and Controls - Fuel Charging and Controls
Description an
d Operation

This section provides service informatio n for the fuel distribution components located on the engine and includes the
supercharger, where fitted. Refer to Section 310-01 for informatio n on the fuel tank, fuel lines and related fuel supply items.

Fuel Charging and Controls -
Normally Aspirated Vehicles

P
a
rts List
It
e
m
Par
t
Number
De
scr
iption
1—F
u
el feed from tank to bank 2
2—Fue
l
injector
3—Inta
k
e manifold/fuel rail
4—Te
st
/de-pressurization valve
5—F
u
el cross-over pipe
6—F
u
el pressure regulator
7—F
u
el return to tank

Fuel D
istribution
Fuel is supplied to th
e engine
via eight fuel injectors (one pe r cylinder). The injectors are located in two fuel rails which r un
the length of each cylinder bank and ar e integral with the air intake manifold.
Fuel pumped from the tank enters a feed pipe at the rear of bank 2. Fuel flow is along bank 2 fuel rail, across the top front
of the engine (cross-over pipe) and through bank 1 fuel rail, the unused fuel re turning to the tank via a pressure regulator.
The fuel injectors are each controlled electrically from the engine control module (ECM).
A test valve is fitted to the cross-over pipe connecting the fu el rails at the front of the intake manifold. This valve allows the
fuel system to be depr essurized during servicin g and troubleshooting.
Fuel Injector

Eight, side-fed, dual straight-jet fuel injectors are fi tted in the fuel rails.
The injector consists of a solenoid, core, needle valve and ho using. When a control signal from the ECM is applied to the
solenoid coil, the needle valve lifts up and fuel is injected under pressure into the intake port. The fuel sprays from the
injectors are directed onto the back of the intake valves.
The injection quantity is determined by the length of time that the ECM signal is applied to the solenoid coil.
The injectors installed in the fuel rails of supercharged engines are of a higher flow rating than those installed in normally
aspirated engines and are secured in position by spring clips. Seals are instal led between the injector mounts of the fuel
rails and the related re cesses in the charge air cooler adaptors.
Pressure Regulator

Pa
rts List
The pressure regulator is a diap hragm-operated valve that regula tes fuel-rail pressure at 3,0 bar above the intake manifold
pressure. A pipe connects the throttle induction elbow to the pressure regulator to provide the vacuum control signal. On
supercharged engines, the pressure regulator vacuum feed is taken from the top of the supercharger outlet duct.
The regulator is fitted between the rear end of the right-hand fuel rail (bank 1) and the fuel return line to the tank.
Circuit Diagram, Fuel Injection Syst em - Normally Aspirated Vehicles

Ite
m
Par
t
Number
De
scr
iption
1—F
u
el Return
2—F
u
el Pressure Regulator
3—Inta
k
e Manifold Pressure

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