1990 FORD SIERRA ignition

Glossary of Technical termsREF•19
REF
CamshaftA rotating shaft on which a series
of cam lobes operate the valve mechanisms.
The camshaft may be driven by gears, by
sprockets and chain or by sprockets and a
belt.
CanisterA container in an evaporative
emission control system; contains activated
charcoal granules to trap vapours from the
fuel system.
CarburettorA device which mixes fuel with
air in the proper proportions to provide a
desired power output from a spark ignition
internal combustion engine.
CastellatedResembling the parapets along
the top of a castle wall. For example, a
castellated balljoint stud nut.
CastorIn wheel alignment, the backward or
forward tilt of the steering axis. Castor is
positive when the steering axis is inclined
rearward at the top.Catalytic converterA silencer-like device in
the exhaust system which converts certain
pollutants in the exhaust gases into less
harmful substances.
CirclipA ring-shaped clip used to prevent
endwise movement of cylindrical parts and
shafts. An internal circlip is installed in a
groove in a housing; an external circlip fits into
a groove on the outside of a cylindrical piece
such as a shaft.
ClearanceThe amount of space between
two parts. For example, between a piston and
a cylinder, between a bearing and a journal,
etc.
Coil springA spiral of elastic steel found in
various sizes throughout a vehicle, for
example as a springing medium in the
suspension and in the valve train.
CompressionReduction in volume, and
increase in pressure and temperature, of a
gas, caused by squeezing it into a smaller
space.
Compression ratioThe relationship between
cylinder volume when the piston is at top
dead centre and cylinder volume when the
piston is at bottom dead centre.
Constant velocity (CV) jointA type of
universal joint that cancels out vibrations
caused by driving power being transmitted
through an angle.
Core plugA disc or cup-shaped metal device
inserted in a hole in a casting through which
core was removed when the casting was
formed. Also known as a freeze plug or
expansion plug.
CrankcaseThe lower part of the engine
block in which the crankshaft rotates.
CrankshaftThe main rotating member, or
shaft, running the length of the crankcase,
with offset “throws” to which the connecting
rods are attached.Crocodile clipSee Alligator clip
DDiagnostic codeCode numbers obtained by
accessing the diagnostic mode of an engine
management computer. This code can be
used to determine the area in the system
where a malfunction may be located.
Disc brakeA brake design incorporating a
rotating disc onto which brake pads are
squeezed. The resulting friction converts the
energy of a moving vehicle into heat.
Double-overhead cam (DOHC)An engine
that uses two overhead camshafts, usually
one for the intake valves and one for the
exhaust valves.
Drivebelt(s)The belt(s) used to drive
accessories such as the alternator, water
pump, power steering pump, air conditioning
compressor, etc. off the crankshaft pulley.
DriveshaftAny shaft used to transmit
motion. Commonly used when referring to the
axleshafts on a front wheel drive vehicle.
Drum brakeA type of brake using a drum-
shaped metal cylinder attached to the inner
surface of the wheel. When the brake pedal is
pressed, curved brake shoes with friction
linings press against the inside of the drum to
slow or stop the vehicle.
Castellated nut
Catalytic converter
Crankshaft assembly
Carburettor
Canister
Drum brake assembly
Accessory drivebelts
Driveshaft

REF•20Glossary of Technical terms
EEGR valveA valve used to introduce exhaust
gases into the intake air stream.
Electronic control unit (ECU)A computer
which controls (for instance) ignition and fuel
injection systems, or an anti-lock braking
system. For more information refer to the
Haynes Automotive Electrical and Electronic
Systems Manual.
Electronic Fuel Injection (EFI)A computer
controlled fuel system that distributes fuel
through an injector located in each intake port
of the engine.
Emergency brakeA braking system,
independent of the main hydraulic system,
that can be used to slow or stop the vehicle if
the primary brakes fail, or to hold the vehicle
stationary even though the brake pedal isn’t
depressed. It usually consists of a hand lever
that actuates either front or rear brakes
mechanically through a series of cables and
linkages. Also known as a handbrake or
parking brake.
EndfloatThe amount of lengthwise
movement between two parts. As applied to a
crankshaft, the distance that the crankshaft
can move forward and back in the cylinder
block.
Engine management system (EMS)A
computer controlled system which manages
the fuel injection and the ignition systems in
an integrated fashion.
Exhaust manifoldA part with several
passages through which exhaust gases leave
the engine combustion chambers and enter
the exhaust pipe.
FFan clutchA viscous (fluid) drive coupling
device which permits variable engine fan
speeds in relation to engine speeds.Feeler bladeA thin strip or blade of hardened
steel, ground to an exact thickness, used to
check or measure clearances between parts.
Firing orderThe order in which the engine
cylinders fire, or deliver their power strokes,
beginning with the number one cylinder.
Flywheel A heavy spinning wheel in which
energy is absorbed and stored by means of
momentum. On cars, the flywheel is attached
to the crankshaft to smooth out firing
impulses.
Free playThe amount of travel before any
action takes place. The “looseness” in a
linkage, or an assembly of parts, between the
initial application of force and actual
movement. For example, the distance the
brake pedal moves before the pistons in the
master cylinder are actuated.
FuseAn electrical device which protects a
circuit against accidental overload. The typical
fuse contains a soft piece of metal which is
calibrated to melt at a predetermined current
flow (expressed as amps) and break the
circuit.
Fusible linkA circuit protection device
consisting of a conductor surrounded by
heat-resistant insulation. The conductor is
smaller than the wire it protects, so it acts as
the weakest link in the circuit. Unlike a blown
fuse, a failed fusible link must frequently be
cut from the wire for replacement.
GGapThe distance the spark must travel in
jumping from the centre electrode to the sideelectrode in a spark plug. Also refers to the
spacing between the points in a contact
breaker assembly in a conventional points-
type ignition, or to the distance between the
reluctor or rotor and the pickup coil in an
electronic ignition.
GasketAny thin, soft material - usually cork,
cardboard, asbestos or soft metal - installed
between two metal surfaces to ensure a good
seal. For instance, the cylinder head gasket
seals the joint between the block and the
cylinder head.
GaugeAn instrument panel display used to
monitor engine conditions. A gauge with a
movable pointer on a dial or a fixed scale is an
analogue gauge. A gauge with a numerical
readout is called a digital gauge.
HHalfshaftA rotating shaft that transmits
power from the final drive unit to a drive
wheel, usually when referring to a live rear
axle.
Harmonic balancerA device designed to
reduce torsion or twisting vibration in the
crankshaft. May be incorporated in the
crankshaft pulley. Also known as a vibration
damper.
HoneAn abrasive tool for correcting small
irregularities or differences in diameter in an
engine cylinder, brake cylinder, etc.
Hydraulic tappetA tappet that utilises
hydraulic pressure from the engine’s
lubrication system to maintain zero clearance
(constant contact with both camshaft and
valve stem). Automatically adjusts to variation
in valve stem length. Hydraulic tappets also
reduce valve noise.
IIgnition timingThe moment at which the
spark plug fires, usually expressed in the
number of crankshaft degrees before the
piston reaches the top of its stroke.
Inlet manifoldA tube or housing with
passages through which flows the air-fuel
mixture (carburettor vehicles and vehicles with
throttle body injection) or air only (port fuel-
injected vehicles) to the port openings in the
cylinder head.
Exhaust manifold
Feeler blade
Adjusting spark plug gap
Gasket
EGR valve

refitting - 2A•10, 2B•7, 2C•9
removal - 2A•8, 2B•4, 2C•6
SOHC engines- 2A•1et seq
spark plugs - 1•2, 1•14, 5•12
sump - 2A•20, 2B•15, 2C•19
timing belt/chain and sprockets - 2A•12,
2B•8, 2C•10
timing and sprockets - 2A•12, 2B•8, 2C•10
valves - 1•15
Engine electrical systems - 5•1 et seq
Environmental considerations- REF•4
Exhaust gas oxygen sensor (HEGO)- 4B•15
Exhaust gas recirculation valve- 4B•14
Exhaust manifold- 4A•17, 4B•15
Exhaust pressure transducer- 4B•14
Exhaust system- 1•11, 4A•18, 4B•15
Expansion tank/coolant sensor- 3•8
FFacia panel- 12•16
Facia panel switches- 13•4
Fan (radiator)- 3•7
Fault diagnosis- REF•11
automatic transmission - REF•14
braking system - REF•15
clutch - REF•14
cooling system - REF•13
driveshafts - REF•15
electrical system - REF•16
engine - REF•12
final drive - REF•15
fuel and exhaust systems - REF•13
manual gearbox - REF•14
propeller shaft - REF•15
steering - REF•16
suspension - REF•16
Final drive and driveshafts- 9•1 et seq
Final drive fault diagnosis- REF•11, REF•15
Final drive unit- 9•2, 9•3, 9•4
Fluids- 0•17
Flywheel/driveplate- 2A•18, 2B•15, 2C•19
Foglamps- 13•15
Ford VV carburettor- 1•12, 4A•13
Front suspension crossmember- 11•3
Front suspension strut- 11•4
Fuel systems- carburettor - 4A•1 et seq
Fuel systems- fuel injection - 4B•1 et seq
Fuel system:
accelerator cable - 4A•8
accelerator pedal - 4A•8
air cleaner - 1•18, 1•19, 4A•4, 4B•4
airflow meter - 4B•8
catalytic converter - 4B•3, 4B•14
CFI unit- 4B•10
depressurising fuel injection system - 4B•4
dismantling and reassembly - 4A•8
electronic vacuum regulator - 4B•11
exhaust gas recirculation valve - 4B•14
exhaust gas oxygen sensor (HEGO) - 4B•15
exhaust manifold - 4A•17, 4B•15
exhaust pressure transducer - 4B•14
exhaust system - 4A•18, 4B•15
fuel filler cap - 12•14
fuel filter - 1•2, 1•20
fuel level sender unit - 4A•7, 4B•7fuel pressure regulator - 4A•5, 4B•5
fuel pump - 4A•5, 4A•6, 4B•6
fuel tank - 4A•7
fuel vapour separator - 4A•5
fuel gauges - 13•8
idle speed control valve - 4B•7
injector(s) - 4B•8
inlet manifold - 4A•15, 4B•12
mixture adjustment potentiometer - 4B•7
pulse-air - 4B•10
throttle body - 4B•12
throttle control motor - 4B•11
throttle position sensor - 4B•11
throttle valve control motor - 4B•11
Fuses- 13•3
GGear linkage- 7A•4
Gear selector mechanism- 7B•5
Gearbox - see Manual gearbox or
Automatic transmission
Gearbox oil- 0•17, 1•3
Glass- 12•11
HHandbrake check/adjustment- 1•16, 10•21
Handbrake cables- 10•20, 10•21
Handbrake lever - 10•22
Handbrake warning lamp switch- 13•6
Handles (door)- 12•9
Hazard warning flasher switch- 13•4
Headlamp alignment- 13•14
Headlamp unit- 13•13
Headlamp washers- 13•12
Headlining - 12•19
Heated rear window- 13•20
Heated seat- 13•19
Heater- 3•9
Hinges and locks- 1•14
Horn- 13•11
Horn switch- 13•5
Hose and fluid leak check- 0•8, 1•10,
Hoses brake- 10•19
Hoses power steering- 11•18
HT coil- 5•13
HT leads- 5•12
Hub carrier (front) - 11•5
Hydraulic fluid- 0•17
Hydraulic system (brakes) bleeding- 10•2
Hydraulic unit, pump, motor (ABS)- 10•15,
10•16
IIdle speed control valve- 4B•7
Idle speed/mixture- 1•11, 1•12, see
Specifications in Chapter 4A, and refer to
specific carburettor type
Ignition electronic modules- 5•3, 5•19
Ignition HT coil- 5•13
Ignition switch- 13•4
Ignition system check- 1•20
Ignition timing adjustment- 5•17
Indicator lamps- 13•15Indicator switch/relay- 13•4
Injector(s)- 4B•8
Inlet manifold- 4A•15, 4B•12
Instrument panel- 13•7
Interior trim- 12•15
Introduction to the Ford Sierra- 0•4
JJacking and vehicle support- 0•6
Jump starting- 0•9
KKickdown cable - 7B•3
LLeaf springs- 11•13
Leak, checking- 0•8, 1•10
Lights- 13•14
Locks:
bootlid - 12•5
door - 12•9, 12•10
tailgate - 12•6
Loudspeakers- 13•20
Lower arm (suspension)- 11•4, 11•7, 11•8
Lubricants and fluids- 0•17
Luggage area light switch- 13•5
MMain bearings- 2A•23, 2B•17, 2C•23
Maintenance and servicing - see Routine
maintenance
Manifolds- 4A•15, 4A•17, 4B•12, 4B•15
Manual gearbox- 7A•1 et seq
fault diagnosis - REF•11, REF•14
gear linkage - 7A•4
gearbox oil - 0•17, 1•3
oil level check - 1•13
removal and refitting - 7A•2
Master cylinder (brake)- 10•13
Mirrors- 12•12
Mixture (CO)- see Idle speed/mixture
Mixture adjustment potentiometer- 4B•7
MOT test checks- REF•7
Mountings, engine-2A•11, 2B•7, 2C•9
NNumber plate lamp- 13•16
OOil change/filter- 1•1, 1•9,
Oil pressure warning switch- 13•6
Oil pump- 2A•21, 2B•16, 2C•20
Oil seals- REF •4
Oil seals crankshaft- 2A•19, 2B•15, 2C•19
Oils- engine and gearbox- 0•17, 1•3
PPads (brake) - 10•3
Paintwork damage- 12•2
Parts- REF•3
REF•24Index

Pedals:
accelerator - 4A•8
brake - 10•22
clutch - 6•2
Pierburg 2V carburettor- 1•12, 4A•14
Pipes/hoses (braking system)- 10•19
Pistons- 2A•22, 2B•17, 2C•21
Plastic components- 12•3
Plugs- 1•2, 1•14, 5•12
Power operated windows- 13•18
Power steering fluid- 0•17
Power steering fluid level- 0•14
Power steering fluid hoses-11•18
Power steering pump- 11•18
Power steering system bleeding- 11•18
Pressure switch (hydraulic unit)- 10•17
Propeller shaft- 8•1 et seq
centre bearing - 8•2
fault diagnosis - REF•11, REF•15
front rubber coupling - 8•3
removal and refitting - 8•2
vibration damper - 8•4
Pulse-air system- 4B•10
Punctures- 0•6
RRadiator- 1•16, 3•3
Radiator cooling fan- 3•7
Radiator grille- 12•14
Radio/cassette player- 13•21
Rear axle- 9•7, 9•8, 11•13
Relays- 13•3
Release bearing (clutch)- 6•5
Repair procedures- REF •4
Respraying- 12•2
Reversing lamp switch- 7B•6, 13•4
Roadtest- 1•17
Roadwheel check- 1•11
Roll bars- 11•6, 11•13
Rotor arm- 5•14, 5•15
Routine maintenance and servicing- 1•1 et seq
Routine maintenance procedures- 1•9
Routine maintenance schedule- 1•3
SSafety first!- 0•5
Scratches- 12•2
Seat belts- 1•11, 12•21
Seat heating pad- 13•19
Seats- 12•19
Selector rod- 7B•5
Sender unit fuel level- 4A•7, 4B•7
Sender units coolant temperature- 3•8
Servicing -see Routine maintenance
Servo unit (braking system)- 10•14
Shock absorber- 11•9
Shoes (brake)- 10•6
Short-circuit finding- 13•3
Spare parts- REF•3
Spark plugs- 1•2, 1•14, 5•12
Speakers- 13•20Specifications- see start of relevant Chapter
Speedometer- 13•8
Speedometer cable- 13•11
Spoiler- 12•6
Starter inhibitor switch- 7B•6
Starter motor- 5•8
Steering- 11•1 et seq
check -1•17, 1•18
column/adjustment - 11•15
fault diagnosis - REF•11, REF•16
gear - 11•16, 11•18
hoses - 11•18
power steering system bleeding - 11•18
pump - 11•18
tie-rod end - 11•18
wheel - 11•14
wheel alignment - 11•1, 11•19
Sump- 2A•20, 2B•15, 2C•19
Sunroof- 12•15, 13•6
Support struts (tailgate)- 12•6
Suspension and steering- 11•1 et seq
anti-roll bars - 11•6, 11•13
check - 1•17, 1•18
coil spring (rear) - 11•10
crossmember (front) - 11•3
fault diagnosis - REF•11, REF•16
hub carrier (front) - 11•5
leaf springs - 11•13
lower arm (front/rear) - 11•4, 11•7, 11•8
mountings - 11•12
rear axle assembly - 11•13
shock absorber - 11•9
strut (front) - 11•4
wheel bearings - 11•6, 11•10
Switches:
brake lamp - 13•6
cooling system - 3•8
courtesy lamp - 13•5
direction indicator - 13•4
electric door mirror - 13•5
facia panel - 13•4
handbrake warning lamp - 13•6
hazard warning lamp - 13•4
horn - 13•5
hydraulic pressure (brakes) - 10•17
ignition/lockbarrel - 13•4
luggage area light - 13•5
oil pressure warning - 13•6
reversing - 7B•6, 13•4
starter inhibitor - 7B•6
TTachometer- 13•8
Tailboard- 12•11
Tailgate struts- 12•6
Tailgate/lock- 12•5, 12•6
Temperature gauge and sender unit- 3•8
Thermostat- 3•4
Throttle body- 4B•12
Throttle cable- 4A•8
Throttle position sensor- 4B•11
Throttle valve control motor- 4B•11Tie-rod end- 11•18
Timing adjustment- 5•17
Timing belt/chain and sprockets- 2A•12,
2B•8, 2C•10
Tools and working facilities- REF•5
Towing- 0•7
Transmission housing oil seal- 7B•5
Trim panel (door)- 12•7
Tyre checks and pressures- 0•16, 0•18
UUnderbody- 1•7 1•8, 1•17, 12•2
Underbonnet views -0•10, 1•5
Unleaded petrol- 5•18
Upholstery and carpets- 12•2
VVacuum diaphragm unit- 7B•6
Vacuum servo unit (braking system)- 10•14
Valve block (ABS)- 10•17
Valves- 1•15
Vehicle identification numbers- REF•3
Ventilation system- 3•1 et seq
WWarning system components- 13•9
Washer fluid level- 0•13
Washers- 13•12
Weatherstrip- 12•15
Weber 2V carburettor- 1•12, 4A•14
Weber 2V TLD carburettor- 1•12, 4A•15
Weekly checks- 0•10
Wheel (steering) - 11•14
Wheel alignment- 11•1, 11•19
Wheel arch liners- 12•14
Wheel bearings- 11•6, 11•10
Wheel changing- 0•6
Wheel cylinder- 10•12
Wheel sensor(ABS)- 10•18
Window glass- 12•11
Window regulator- 12•12
Windscreen- 12•11, 12•14
Windscreen washers- 13•12
Windscreen wiper motor- 13•12
Wiper arms- 13•11
Wiper blades- 0•15, 13•11
Wiper motor (headlamp)- 13•13
Wiper motor (rear)- 13•12
Wiper motor (windscreen)- 13•12
Wiring diagrams- WD•1 et seq
Working facilities- REF•5
IndexREF•25
REF