Wiring diagrams 12•23
12
Key to wiring diagrams for 1989 models
E1Sidelamp - left406
E2Tail lamp -left302, 380, 407
E3Number plate lamp413
E4Side lamp right409
E5Tail lamp right382, 410
E6Engine compartment lamp416
E7Headlamp main beam - left437
E8Headlampmain beam - right438
E9Headlampdipped beam - left384, 439
E10Headlamp dipped beam - right386, 440
E11Instrument illumination lamps328 to 329
E12Gear selector lever illumination lamp (automatics)799
E13Luggage compartment lamp485
E14Courtesy lamp487
E15Glovebox lamp599
E16Cigarette lighter illumination lamp598
E17Reversing lamp - left497
E18Reversing lamp - right498
E19Heated rearwindow572
E20Front foglamp -left448
E21Front foglamp - right447
E24Rear foglamp - left454
E25Seat heater -front left575
E30Seat heater - front right579
E32Clock illumination lamp552
E38Trip computer illumination lamp539
E39Rear foglamp - right455
E41Courtesy lamp (with delay)488 to 490
E50Kerb lamp - driver’s door635
E51Kerb lamp - passenger door653
F1 toFuse (in fusebox)Various
F30
F32Fuse - mixture preheating (not UK)232
F33Fuse - electronic carburettor (not UK)201
F34Fuse (in relay box, engine compartment)834
F35Voltage stabiliser302
F36Fuse - fuel filter heating (Diesel models)866
G1Battery101
G2Alternator110
G3Battery - Diesel models846
G6Alternator - Diesel models850 to 852
H2Horn591
H3Direction indicator warning lamp318, 320
H4Oil pressure warning lamp310
H5Brake fluid level warning lamp313
H6Hazard warning flasher warning lamp470
H7Alternator charge warning lamp310
H8Headlamp main beam warning lamp322
H9Brake lamp - left388
H10Brake lamp - right390H11Direction indicator lamp - front left472
H12Direction indicatorlamp - rear left473
H13Direction indicator lamp - front right481
H14Direction indicator lamp - rear right482
H16Glow plug warning lamp (Diesel models)323
H17Trailer direction indicator warning lamp321
H18Horns (twin)592, 593
H19Headlamps-on warning buzzer494, 495
H21Handbrake-on warning lamp315
H23Radio/cassette player585, 586
H25Door mirror heater warning lamp678
H26ABS warning lamp319
H30Engine fault warning lamp324
H33Direction indicator side repeater lamp - left476
H34Direction indicator side repeater lamp - right478
H42Automatic transmission warning lamp325
H45Four-wheel-drive warning lamp327
H46Catalytic converter temperature warning lamp (not UK)329
K1Relay-heated rear window571 to 572
K5Relay - front foglamps448 to 450
K6Relay - air conditioning (not UK)801 to 802
K7Relay - air conditioning blower (not UK)808 to 809
K8Relay - intermittent windscreen wipe503 to 506
K9Relay - headlamp wash522 to 523
K10Relay - direction indicator/hazard warning flashers467 to 469
K20HEI ignition control unit122 to 124
K25Relay - glow plugs (Diesel models)856 to 859
K30Relay - intermittent rear window wipe515 to 517
K35Relay - door mirror heater683 to 685
K37Central locking control unit606 to 612
K45Relay - mixture preheating (not UK)231 to 232
K47Relay - surge arrester (ABS)702 to 703
K50ABS control unit707 to 721
K51Relay - cooling fan830 to 831
K54Electronic carburettor control unit (not UK)203 to 226
K55Relay - electronic carburettor (not UK)203 to 206
K57Fuel injection control unit (not UK)139 to 161
K58Relay -fuel pump (not UK)162 to 163
K59Relay - daytime running lamps (not UK)420 to 426
K61Motronic M4.1 control unit170 to 194
K62Dim-dip control unit428 to 432
K63Relay - horn593 to 594
K64Relay - air conditioning blower (not UK)802 to 803
K67Relay -cooling fan827 to 828
K68Relay -fuel injection system294 to 299, 196 to 199
K69Motronic M2.5 control unit267 to 297
K71Ride control unit (not UK)739 to 754
K80Relay -fuel filter heater (Diesel models)865 to 866
K82Relay - engine revolution862 to 863
K83Four-wheel-drive control unit725 to 731 NoDescriptionTrackNoDescriptionTrack
12•38Wiring diagrams
Key to wiring diagrams for 1991 models
NoDescriptionTrackNoDescriptionTrack Wiring diagrams for 1991 models
Location of applicable circuitsTrackLocation of applicable circuitsTrack
Air conditioning system800 to 850
Alternator111
Anti-lock braking system (ABS)701 to 722
Anti-theft alarm system633 to 647
Automatic transmission control system773 to 799
Battery100
Brake lamps461 to 462
Carburettor118 to 121
Central locking system600 to 627
Check control system347 to 371
Cigarette lighter597 to 598
Clock661 to 663
Courtesy lamps - front487 to 494
Courtesy lamps - rear569 to 573
Direction indicator and hazard warning lamps467 to 482
Door mirrors536 to 548
Electric windows665 to 699
Engine compartment lamp415
Foglamps - front444 to 452
Foglamps - rear444 to 457
Fuel injection and ignition (Multec) - C16NZ engine129 to 164
Fuel injection and ignition (Multec) - C18NZ engine972 to 997
Fuel injection/ignition (Motronic M1.5) - 2.0litre sohc 168 to 199
Fuel injection/ignition (Motronic M2.5) - 2.0litre dohc 261 to 299
Glovebox lamp599Headlamp aim adjustment system758 to 766
Headlamp dim-dip427 to 431
Headlamp washers519 to 532
Headlamps437 to 442
Headlamps “ON” warning buzzer493 to 495
Heated front seats560 to 566
Heated rear window549 to 556
Heater blower motor853 to 862
Horn(s)592 to 596
Ignition (HEI) - 14NV engine121 to 128
Ignition (MSTS/EZ+) - 16SV, 18 SV engines236 to 256
Instruments301 to 344
Luggage compartment lamp485
Radiator cooling fan113, 115
Radio/cassette player586 to 591
Rear number plate lamp413
Reversing lamps496 to 498
Side and tail lamps401 to 410
Starter motor102 to 110
Sunroof863 to 870
Tailgate wiper510 to 516
Trip computer650 to 662
Windscreen and tailgate washers511 to 529
Windscreen wipers501 to 506
E1Side lamp - left406
E2Tail lamp - left356, 374, 407
E3Number plate lamp413
E4Side lamp - right409
E5Tail lamp - right358, 376, 410
E6Engine compartment lamp415
E7Headlamp main beam - left437
E8Headlamp main beam - right438
E9Headlamp dipped beam - left360, 378, 439
E10Headlamp dipped beam - right362, 380, 440
E11Instrument illumination lamps328 to 329
E12Selector lever illumination lamp (automatic transmission)799
E13Luggage compartment lamp485
E14Courtesy lamp487
E15Glovebox lamp599
E16Cigarette lighter illumination lamp596
E17Reversing lamp - left497
E18Reversing lamp - right498
E19Heated rear window552
E20Front foglamp - left448
E21Front foglamp - right447
E24Rear foglamp - left454
E25Driver’s seat heater580
E27Courtesy lamp - rear left569 to 570
E28Courtesy lamp - rear right572 to 573
E30Passenger front seat heater564
E32Clock illumination lamp663
E38Trip computer illumination lamp654
E39Rear foglamp - right455
E41Courtesy lamp (with delay)488 to 490
E50Kerb lamp - driver’s door666
E51Kerb lamp - passenger door684
F1 onFusesVarious
G1Battery101
G2Alternator111
G3Battery - (Diesel models)882, 901
G6Alternator - (Diesel models)884 to 886, 909 to 911H1Radio/cassette player589 to 590, 634
H2Horn592
H3Direction indicator warning lamp315 to 320
H4Oil pressure warning lamp310
H5Brake fluid level warning lamp313
H6Hazard warning flasher lamp470
H7Alternator charge warning lamp310
H8Headlamp main beam warning lamp322
H9Brake lamp - left364, 382, 461
H10Brake lamp - right366, 384, 462
H11Direction indicator lamp - front left472
H12Direction indicator lamp - rear left473
H13Direction indicator lamp - front right461
H14Direction indicator lamp - rear right482
H15Fuel level warning lamp305
H16Glow plug warning lamp (Diesel models)323
H17Trailer direction indicator warning lamp321
H18Horn593
H19Headlamps-on warning buzzer494 to 495
H21Handbrake-on warning lamp315
H25Door mirror warning lamp542, 952
H26ABS warning lamp319
H30Engine fault warning lamp324
H33Direction indicator side repeater lamp - left476
H34Direction indicator side repeater lamp - right478
H42Automatic transmission warning lamp325
H45Four-wheel-drive warning lamp327
H46Catalytic converter temperature warning lamp329
H47Anti-theft alarm horn638
H48Horn594
K3Relay - starter motor (anti-theft alarm)109 to 110
K5Relay - front foglamps448 to 450
K6Relay - air conditioning801 to 802
K7Relay - air conditioning blower804 to 805
K8Relay - intermittent windscreen wipe503 to 506
K9Relay - headlamp wash519 to 520
K10Relay - direction indicator/hazard warning flashers467 to 469
Wiring diagrams 12•55
12
Key to wiring diagrams for 1992 and later models
NoDescriptionTrackNoDescriptionTrack
E1Left parking lamp506
E2Left tail lamp507, 745
E3Licence plate lamp513
E4Right parking lamp509
E5Right tail lamp510, 746
E6Engine compartment lamp515
E7Left high beam 535
E8Right high beam536
E9Left low beam537, 747
E10Right low beam538, 748
E11Instrument lights728, 729
E12Selector lever lamp 498, 499
E13Boot lamp585
E14Passenger compartment lamp587
E15Glove box lamp677
E16Cigarette lighter lamp676
E17Left reversing lamp597
E18Right reversing lamp598
E19Heated back window652
E20Left fog lamp553
E21Right fog lamp554
E24Left rear fog lamp548
E25Left front heating mat660
E27Left rear reading lamp680, 681
E28Right rear reading lamp683, 684
E30Right front heating mat664
E32Clock lamp863
E37Left mirror make-up lamp686
E38Computer lamp854
E39Right rear foglamp549
E40Right mirror make-up lamp688
E41Passenger compartment delay lamp 588 to 590
E50Driver door lamp866
E51Passenger door lamp884
F1 onFusesVarious
F35Voltage stabilizer702
G1Battery101
G2Alternator114
G6Diesel alternator 402 to 405
H1Radio784 to 798
H3Turn signal lamp telltale716, 718
H4Oil pressure telltale710
H5Brake fluid telltale712
H6Telltale hazard warning system570
H7Charging indicator lamp710
H8High beam telltale722
H9Left stop lamp561, 749
H10Right stop lamp562, 750
H11Left front turn signal lamp572
H12Left rear turn signal lamp573
H13Right front turn signal lamp581
H14Right rear turn signal lamp582
H15Fuel telltale705, 706
H16Preheating time telltale715
H17Trailer turn signal lamp telltale717
H18Horn670
H19Headlamps on warning buzzer594, 595
H21Parking brake telltale713
H23Airbag telltale719
H25Heated back window & mirror telltale642, 765
H26ABS telltale721
H27Safety checking warning buzzer996 to 998
H28Seat belt warning telltale723
H30Engine telltale724H33Left auxiliary turn signal lamp576
H34Right auxiliary turn signal lamp578
H36Additional stop lamp563
H37Left front loudspeaker788 to 790
H38Right front loudspeaker794 to 796
H39Left rear loudspeaker788, 789
H40Right rear loudspeaker791, 792
H42Automatic program power telltale725
H45Four wheel drive telltale727
H46Catalytic converter temperature telltale729
H47Anti-theft warning unit horn838
H48Horn671
H51Traction control telltale720
H52Left front tweeter787 to 791
H53Right front tweeter793 to 797
K3Starter relay anti-theft warning unit109, 110
K5Fog lamps relay554 to 555
K6Air conditioning relay901, 902
K7Four stage air conditioning blower relay904, 905
K8Windshield wiper interval relay603 to 606
K9Headlamps washer unit relay619, 620
K10Flasher unit567 to 569
K20Ignition coil module149, 150, 171, 172, 241, 242, 302 to 305,
361 to 364, 1001 to 1005, 1055 to 1061
K22Coolant pump relay133, 134, 969, 970
K25Glow time relay440 to 443
K26Radiator blower relays972 to 974
K27Radiator blower relay137 to 139
K30Back window wiper interval relay613 to 615
K31Airbag control unit1191 to 1198
K34Radiator blower time delay relay356 to 358, 956 to 958
K35Heated back window & mirror time delay relay650 to 652
K37Central locking control unit805 to 812
K51Radiator blower relay430, 431, 942, 943, 956, 957
K52Radiator blower relay145 to 147, 433,435,
982 to 984, 960 to 962
K57Multec unit control211 to 230, 244 to 262
K58Fuel pump relay231, 232, 262, 263
K59Running light relay520 to 525
K60Compressor relay931,932
K61Motronic control unit270 to 294, 307 to 337,
366 to 396, 1007 to 1037, 1063 to 1096
K63Horn relay671, 672
K641 stage air conditioning blower relay913, 914
K67Radiator blower relay142, 143, 436, 437, 948,
949, 964, 965, 986, 987
K68Fuel injection unit relay295 to 299, 393 to 397,
334 to 338, 1093 to 1097, 1034 to 1038
K73High beam relay (Calibra)530, 531
K76Glow time control unit413 to 417
K77Glow plugs relay419, 420
K78Preresistor relay (70A)422, 423
K79Charge indicator relay406 to 408
K80Filter heating relay426, 427, 452, 453
K82Engine revolution relay447, 448
K83Four wheel drive unit control342 to 349
K84EZ Plus control unit155 to 166, 177 to 191
K85Automatic transmission control unit473 to 496
K86Check control unit736 to 752
K87Radiator blower relay945, 946, 953, 954, 977, 978
K88Catalytic converter temperature control unit462 to 464
K89Rear fog lamp relay543 to 545
K90Compressor relay (automatic transmission only)930, 931
K94Anti-theft warning unit control unit833 to 847
Aluminium or plastic mesh, or glass fibre
matting, is probably the best material to use
for a large hole. Cut a piece to the
approximate size and shape of the hole to be
filled, then position it in the hole so that its
edges are below the level of the surrounding
bodywork. It can be retained in position by
several blobs of filler paste around its
periphery.
Aluminium tape should be used for small or
very narrow holes. Pull a piece off the roll and
trim it to the approximate size and shape
required. Then pull off the backing paper (if
used) and stick the tape over the hole. It can
be overlapped if the thickness of one piece is
insufficient. Burnish down the edges of the
tape with the handle of a screwdriver or
similar, to ensure that the tape is securely
attached to the metal underneath.
Bodywork repairs filling and
re-spraying
Before using this Section, see the Sections
on dent, deep scratch, rust holes and gash
repairs.
Many types of bodyfiller are available, but
generally those proprietary kits that contain a
tin of filler paste and a tube of resin hardener
are best for this type of repair. These can be
used directly from the tube. A wide, flexible
plastic or nylon applicator will be found
invaluable for imparting a smooth and well-
contoured finish to the surface of the filler.
Mix up a little filler on a clean piece of card
or board - measure the hardener carefully
(follow the maker’s instructions on the pack)
otherwise the filler will set too rapidly or too
slowly. Using the applicator apply the filler
paste to the prepared area; draw the
applicator across the surface of the filler to
achieve the correct contour and to level the
filler surface. When a contour that
approximates to the correct one is achieved,
stop working the paste - if you carry on too
long the paste will become sticky and begin to
“pick up” on the applicator. Continue to add
thin layers of filler paste at twenty-minute
intervals until the level of the filler is just proud
of the surrounding bodywork.
Once the filler has hardened, excess can be
removed using a metal plane or file. From then
on, progressively finer grades of abrasive
paper should be used, starting with a 40
grade production paper and finishing with 400
grade wet-and-dry paper. Always wrap the
abrasive paper around a flat rubber, cork, or
wooden block otherwise the surface of the
filler will not be completely flat. During the
smoothing of the filler surface the wet-and-dry
paper should be periodically rinsed in water.
This will ensure that a very smooth finish is
imparted to the filler at the final stage.
At this stage the “dent” should be
surrounded by a ring of bare metal, which in
turn should be encircled by the finely
“feathered” edge of the good paintwork.
Rinse the repair area with clean water, until all
the dust produced by the rubbing-down
operation has gone.Spray the whole repair area with a light coat
of primer. This will show up any imperfections
in the surface of the filler. Repair these
imperfections with fresh filler paste or
bodystopper, and again smooth the surface
with abrasive paper. If bodystopper is used, it
can be mixed with cellulose thinners to form a
thin paste that is ideal for filling small holes.
Repeat this spray and repair procedure until
you are satisfied that the surface of the filler,
and the feathered edge of the paintwork are
perfect. Clean the repair area with clean water
and allow to dry fully.
The repair area is now ready for final
spraying. Paint spraying must be carried out
in a warm, dry, windless and dust free
atmosphere. This condition can be created
artificially if you have access to a large indoor
working area, but if you are forced to work in
the open, you will have to pick your day very
carefully. If you are working indoors, dousing
the floor in the work area with water will help
to settle the dust that would otherwise be in
the atmosphere. If the repair area is confined
to one body panel, mask off the surrounding
panels; this will help to minimise the effects of
a slight miss-match in paint colours.
Bodywork fittings (e.g. chrome strips, door
handles, etc.), will also need to be masked off.
Use genuine masking tape and several
thicknesses of newspaper for the masking
operations.
Before beginning to spray, agitate the
aerosol can thoroughly, then spray a test area
(an old tin, or similar) until the technique is
mastered. Cover the repair area with a thick
coat of primer; the thickness should be built
up using several thin layers of paint rather
than one thick one. Using 400 grade
wet-and-dry paper, rub down the surface of
the primer until it is smooth. While doing this,
the work area should be thoroughly doused
with water, and the wet-and-dry paper
periodically rinsed in water. Allow to dry
before spraying on more paint.
Spray on the top coat, again building up the
thickness by using several thin layers of paint.
Start spraying in the centre of the repair area
and then work outwards, with a side-to-side
motion, until the whole repair area and about
2 inches of the surrounding original paintwork
is covered. Remove all masking material 10 to
15 minutes after spraying on the final coat of
paint.
Allow the new paint at least two weeks to
harden, then using a paintwork renovator or a
very fine cutting paste, blend the edges of the
paint into the existing paintwork. Finally, apply
wax polish.
Plastic components
With the use of more and more plastic body
components (e.g. bumpers, spoilers, and in
some cases major body panels), repair of
more serious damage to such items has
become a matter of either entrusting repair
work to a specialist in this field, or renewing
complete components. Repair of suchdamage by the DIY owner is not feasible
owing to the cost of the equipment and
materials required for effecting such repairs.
The basic technique involves making a groove
along the line of the crack in the plastic using
a rotary burr in a power drill. The damaged
part is then welded back together by using a
hot air gun to heat up and fuse a plastic filler
rod into the groove. Any excess plastic is then
removed and the area rubbed down to a
smooth finish. It is important that a filler rod of
the correct plastic is used, as body
components can be made of a variety of
different types (e.g. polycarbonate, ABS,
polypropylene).
Damage of a less serious nature (abrasions,
minor cracks, etc.), can be repaired by the DIY
owner using a two-part epoxy filler repair
material. Once mixed in equal proportions this
is used in similar fashion to the bodywork filler
used on metal panels. The filler is usually
cured in twenty to thirty minutes, ready for
sanding and painting.
If the owner is renewing a complete
component himself, or if he has repaired it
with epoxy filler, he will have a problem of
finding a paint for finishing which is
compatible with the type of plastic used. At
one time the use of a universal paint was not
possible owing to the complex range of
plastics come across in body component
applications. Standard paints, generally, will
not bond to plastic or rubber satisfactorily, but
special paints are available to match any
plastic or rubber finish can be obtained from
dealers. However, it is now possible to obtain
a plastic body parts finishing kit that consists
of a pre-primer treatment, a primer and
coloured top coat. Full instructions are
normally supplied with a kit, but the method of
use is to first apply the pre-primer to the
component concerned and allow it to dry for
up to 30 minutes. Then the primer is applied
and left to dry for about an hour before finally
applying the special coloured top coat. The
result is a correctly coloured component
where the paint will flex with the plastic or
rubber, a property that standard paint does
not normally possess.
5Major body damage - repair
5
Major impact or rust damage should only
be repaired by a Vauxhall dealer or other
competent specialist. Alignment jigs are
needed for successful completion of such
work, superficially effective repairs may leave
dangerous weaknesses in the structure.
Distorted components can also impose
severe stresses on steering and suspension
components with consequent premature
failure.
Bodywork and fittings 11•3
11
37Facia panels - removal and
refitting
3
Footwell trim panels
Removal
1The lower footwell trim panels on the
driver’s and passenger sides are secured by
turnbuckle type plastic clips.2To remove a panel, use a screwdriver to
turn the heads of the clips through 90°(see
illustration), then withdraw the panel from the
facia.
Refitting
3Refitting is a reversal of removal.
Driver’s side lower facia panel
Removal
4Open the flap covering the fusebox to
expose the four lower facia panel securing
screws.
5Remove the four screws, then lower the
panel and pull it towards the driver’s door to
release the two securing clips. Withdraw the
panel from the facia (see illustrations).
Refitting
6Refitting is a reversal of removal.
Steering column shrouds
Removal
7On models with an adjustable tilt steering
column, move the column to its fully raised
position, then unscrew the adjuster lever (see
illustration).
8Turn the steering wheel as necessary to
expose one of the front steering column
shroud securing screw covers.
9Prise out the cover, and remove the column
shroud securing screw, then turn the steering
wheel to enable the remaining cover and
screw to be removed (see illustrations).
10Remove the three securing screws from
the underside of the lower column shroud,
then remove the lower and upper shrouds
(see illustrations).
11•16Bodywork and fittings
37.2 Releasing a footwell trim panel
securing clip37.5B . . . then withdraw the lower facia
panel
37.10C . . . and upper shrouds (steering
wheel removed)37.10B . . . then remove the lower . . .37.10A Remove the three lower column
shroud securing screws . . .
37.9B . . . then remove the front column
shroud securing screws37.9A Prise out the covers . . .37.7 Removing the column adjuster lever
37.5A Remove the four securing screws
from the fusebox aperture . . .
Before removing any of the
facia panels, the battery
negative lead should be
disconnected, as several
permanently live feed wires are routed
behind the facia.
Idle settings (continued)
Idle mixture (CO content):
20 NE and 20 SEH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.0 max.
20 XEJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.7 to 1.2%
All other models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.3 % (at 2800 to 3200 rpm)
Fuel Pressure (regulator vacuum hose connected)
Multec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.76 bar
Motronic 4.1:
Feed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.3 to 2.7 bar
Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.3 to 1.5 bar
Motronic 1.5:
Feed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.8 to 2.2 bar
Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.3 to 1.5 bar
Motronic 2.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.0 to 2.2 bar
Motronic 2.8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.2 to 2.7 bar
Simtec 56.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .not available
Torque wrench settingsNmlbf ft
All specifications as for carburettor models except for the following:
Bracket, tank vent valve to coolant flange . . . . . . . . . . . . . . . . . . . . . . .86
Fuel distributor pipe to inlet manifold . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Fuel flow damper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
Fuel injector retainer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Fuel pressure regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.52
Fuel pump clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Idle air control stepper motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.52
Knock sensor (X16 SZ) to block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1310
Oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3022
Throttle body mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
Throttle body upper-to-lower section . . . . . . . . . . . . . . . . . . . . . . . . . . .64.5
Throttle potentiometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21.5
Throttle valve housing to inlet manifold . . . . . . . . . . . . . . . . . . . . . . . . .97
1General description
General
1All engines available within the Cavalier
range can be operated on unleaded petrol.
Refer to Chapter 5 for further details. Note
that models fitted with a catalytic converter
must only be operated on unleaded petrol,
and leaded petrol must not be used. Models
with catalytic converter can be identified by
the engine code, which is prefixed by the
letter ‘C’ or ‘X’.
Multec system
Note: There is no provision for the adjustment
or alteration of the idle speed; if checking the
idle speed, remember that it may vary
constantly under ECU control.
2The Multec system is essentially a simple
method of air/fuel metering, replacing the
carburettor with a single injector mounted in a
throttle body. This type of system is therefore
also known as Throttle Body Injection (TBi),
Central Fuel Injection (CFi) or single-(or
mono-) point injection. The whole system is
best explained if considered as three
sub-systems, these being fuel delivery, air
metering and electrical control.
3The fuel delivery system incorporates the
fuel tank (with the electric fuel pumpimmersed inside it), the fuel filter, the fuel
injector and pressure regulator (mounted in
the throttle body), and the hoses and pipes
connecting them. When the ignition is
switched on (or when the engine is cranking,
on X16 SZ engines) the pump is supplied with
voltage, by way of the pump relay and fuse
11, under the control of the Electronic Control
Unit (ECU). The pump feeds through the fuel
filter to the injector. Fuel pressure is controlled
by the pressure regulator, which lifts to allow
excess fuel to return to the tank.
4The air metering system includes the inlet air
temperature control system and the air
cleaner, but its main components are in the
throttle body assembly. This incorporates the
injector, which sprays fuel onto the back of the
throttle valve, the throttle potentiometer. This
is linked to the throttle valve spindle and sends
the ECU information on the rate of throttle
opening by transmitting a varying voltage. The
idle air control stepper motor is controlled by
the ECU to maintain the idle speed.
5The electrical side of the fuel injection
system consists of the ECU and all the
sensors that provide it with information, plus
the actuators by which it controls the whole
system’s operation. The basic method of
operation is as follows; note that the ignition
system is controlled by the same ECU.
6The manifold absolute pressure sensor is
connected by a hose to the inlet manifold.
Variations in manifold pressure are converted
into graduated electrical signals that are usedby the ECU to determine the load on the
engine. The throttle valve potentiometer is
explained above.
7Information on engine speed and
crankshaft position comes from the distributor
on C16 NZ engines and from the crankshaft
speed/position sensor on C16 NZ2, X16 SZ
and C18 NZ engines.
8An odometer frequency sensor provides the
ECU with information on the vehicle’s road
speed, and the coolant temperature sensor
provides it with the engine temperature. A
knock sensor located in the cylinder block
between cylinders 2 and 3 on the X16 SZ
engine provides additional information to the
ECU by detecting pre-ignition (detonation)
during the combustion process.
9All these signals are compared by the ECU
with set values pre-programmed (mapped)
into its memory. Considering this information,
the ECU selects the response appropriate to
those values. It controls the ignition amplifier
module by varying the ignition timing as
required. The fuel injector is controlled by
varying its pulse width the time the injector is
held open, to provide a richer or weaker
mixture, as appropriate. The idle air control
stepper motor controls the idle speed. The
fuel pump relay controls the fuel delivery and
the oxygen sensor, accordingly. The mixture,
idle speed and ignition timing are constantly
varied by the ECU to provide the best settings
for cranking, starting and engine warm-up
(with either a hot or cold engine), idling,
4B•2Fuel and exhaust systems - fuel injection models
31This engine is also fitted with an EGR
(exhaust gas recirculation) valve and
secondary air injection (AIR - Air Injection
Reactor), to conform to the latest European
exhaust emission limits (as from 1996). The
EGR returns a specific amount of exhaust gas
into the combustion process. This in turn
reduces the formation of nitrogen oxides
(No
x). The secondary air injection system has
an electrically driven air pump that injects air
into the exhaust manifold, reducing the
amount of CO and HC emissions.
2Fuel injection system -
precautions
The fuel injection system is pressurised,
therefore extra care must be taken when
disconnecting fuel lines. When disconnecting
a fuel line union, loosen the union slowly, to
avoid a sudden release of pressure that may
cause fuel to spray out.
Fuel pressure checking must be entrusted
to a Vauxhall dealer, or other specialist, who
has the necessary special equipment.
3System testing - general
3
General
1Apart from basic electrical tests, there is
nothing that can be done by the owner to test
individual fuel system components.2If a fault arises, check first that it is not due
to poor maintenance. Check that the air
cleaner filter element is clean, the spark plugs
are in good condition and correctly gapped.
Check also that the engine breather hoses are
clear and undamaged and that the throttle
cable is correctly adjusted. If the engine is
running very roughly, check the compression
pressures (Chapter 1) and remember the
possibility that one of the hydraulic tappets
might be faulty, producing an incorrect valve
clearance.
3If the fault is thought to be due to a dirty
injector, it is worth trying one of the
established injector-cleaning treatments
before renewing, perhaps unnecessarily, the
injector.
4If the fault persists, check the ignition
system components (as far as possible).
5If the fault is still not eliminated, work
methodically through the system, checking all
fuses, wiring connectors and wiring, looking
for any signs of poor connections, dampness,
corrosion, dirt or other faults.
6Once the system components have been
checked for signs of obvious faults, take the
vehicle to a Vauxhall dealer for the full system
to be tested on special equipment.
7Do not attempt to “test” any component,
but particularly the ECU, with anything other
than the correct test equipment, available at a
Vauxhall dealer. If any of the wires to be
checked lead to a component such as the
ECU, always first unplug the relevant
connector from the system components so
that there is no risk of the component being
damaged by the application of incorrect
voltages from test equipment.
4Air cleaner - removal and
refitting
2
Note:If ‘round type’ air filter is fitted, follow
procedure in Chapter 4A.
Removal
1Unclip the coolant expansion tank hose
from the air cleaner cover, and move it to one
side out of the way.2Loosen the clamp screw and disconnect
the air trunking from the airflow meter (see
illustration).
3Disconnect the battery negative lead, then
disconnect the wiring plug from the airflow
meter.
4Release the two securing clips from the left-
hand side of the air cleaner cover, and
unscrew the two captive securing screws
from the right-hand side, then lift off the
cover.
5Lift out the filter element.
6Loosen the preheat hoses, fastening nuts.
7Undo the nuts securing the 2 rubber block
studs which are secured through the lower
half of the air cleaner housing.
8Some models are fitted with an inlet air
resonance box, to reduce induction noise.
This box is located under the wheel arch, and
connects to a pipe on the air inlet tube.
9The resonance box must be removed
before the air inlet tube can be removed. To
do this, first apply the handbrake, then jack up
the front of the vehicle, and support securely
on axle stands placed under the body side
members.
10Remove the securing screws, and
withdraw the lower splash shield from the
wing to expose the resonance box.
11Unscrew the single securing screw, and
pull the resonance box from the connector
tube (see illustrations).
12If desired, the air inlet tube can be
removed after pulling off the connector tube
from under the wing (see illustration).
4B•4Fuel and exhaust systems - fuel injection models
4.12 Removing the resonance box
connector tube4.11B . . . and withdraw the resonance box4.11A Remove the securing screw . . .
4.2 Loosening the air trunking clamp
screw at the airflow meter
Warning: Many of the
procedures in this sub-Section
require the removal of fuel lines
and connections that may result
in some fuel spillage. Before carrying out
any operation on the fuel system refer to
the precautions given in Safety first! at
the beginning of this Manual and follow
them implicitly. Petrol is a highly
dangerous and volatile liquid, and the
precautions necessary when handling it
cannot be overstressed.
4B
13Manipulate the air inlet tube to release the
securing lugs from the front body panel. This
is a tricky operation, and patience will be
required. For improved access, the headlamp
can be removed, as described in Chapter 12.
Refitting
14Refitting of all components is a reversal of
removal, noting that the air cleaner element
fits with the rubber locating flange uppermost.
5Air box - removal and refitting
2
Removal
1The air box, if fitted, is secured by two or
three bolts to the top of the throttle body.
Take note of the routing and connections of
the inlet air temperature control system
vacuum pipes.
2Disconnect the engine breather hose from
the air box and the vacuum pipe from the
rearmost of the throttle body’s three unions
(see illustration).
3Do not lose the sealing ring as the air box is
withdrawn.
Refitting
4On refitting, ensure that the sealing ring is
seated correctly in the slot in the underside of
the air box, tighten the screws, and reconnect
the vacuum pipe and breather hose (see
illustrations).
6Air temperature control -
description and testing
3
Description
1Fitted to models with Multec systems, air
temperature is controlled by a thermac switch
(thermostat), mounted in the air box. When
the engine is started from cold, the switch is
closed to allow inlet manifold depression to
act on the air temperature control valve in the
air cleaner assembly. This uses a vacuum
servo in the valve assembly to draw a flap
valve across the cold air inlet thus allowing
only (warmed) air from the exhaust manifold to
enter the air cleaner.2As the temperature of the exhaust warmed
air in the air box rises, a bi-metallic strip in the
thermac switch deforms. This opens the
switch to shut off the depression in the air
temperature control valve. The flap is then
lowered gradually across the hot air inlet. Until
the engine is fully warmed up to normal
operating temperature, only cold air from the
front of the vehicle is entering the air cleaner.
Testing
3To check the system, allow the engine to
cool down completely, then remove the air
cleaner cover; the flap valve should be
securely seated across the hot air inlet. Start
the engine. The flap should immediately rise to
close off the cold air inlet. It should then lower
steadily as the engine warms until it is
eventually seated across the hot air inlet again.
4To check the thermac switch, disconnect
the control valve vacuum pipe from the switch
union (on the rear face of the air box) when the
engine is running. With the engine cold, full
inlet manifold depression should be felt
sucking at the union; none at all should be felt
when the engine is fully warmed up.
5To check the air temperature control valve,
remove the air cleaner cover; the flap valve
should be securely seated across the hot air
inlet. Disconnect the control valve vacuum
pipe from the switch union on the rear face of
the air box and suck hard on its end; the flap
should rise to shut off the cold air inlet.
6If either component is faulty, it must be
renewed. This means renewing the air cleaner
lower casing to obtain a new air temperature
control valve, or renewing the air box in the
case of the thermac switch.
7Air temperature sensor (later
models) - removal and
refitting
2
Removal
1Disconnect the battery negative lead.
2Disconnect the wiring plug at the inlet air
temperature sensor.
3Release the hose clips and remove the air
trunking then remove the inlet air temperature
sensor from the trunking.
Refitting
4Refitting is a reversal of removal but ensure
that the air trunking is connected to the
airflow meter as shown (see illustration).
8Depressurising the fuel
system - general
2
General
1The fuel system consisting of the
tank-mounted fuel pump, the fuel filter, the
fuel injector and the pressure regulator in the
throttle body. Metal pipes and flexible hoses
of the fuel lines connect these components.
All these contain fuel that will be under
pressure while the engine is running and/or
while the ignition is switched on.
2The pressure will remain for some time after
the ignition has been switched off and must
be relieved before any of these components
are disturbed.
3Remove either the fuel pump fuse (num-
ber 11) or the fuel pump relay and start the
engine. Allow the engine to idle until it cuts
out. Turn the engine over once or twice on the
starter to ensure that all pressure is released,
then switch off the ignition.
4Do not forget to refit the fuse or relay when
work is complete.
Fuel and exhaust systems - fuel injection models 4B•5
5.4B Do not overtighten the air box
screws
7.4 Removing the intake air temperature
sensor from the air trunking - later models
5.4A Ensure the sealing ring is located in
the air box groove5.2 Vacuum pipe connections to air box
A To throttle body B To air cleaner
Warning: The following
procedures will merely relieve
the pressure in the fuel system.
Remember that fuel will still be
present in the system components, so
take precautions before disconnecting
any of them. Refer to Section 2.