ignition coil FIAT PUNTO 1996 176 / 1.G User Guide
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Page 153 of 225

5B*1
Chapters PartB:
Ignition system - petrol models
Contents
General information 1 Ignition system - testing 2 Ignriton HT coil - removal, testing and refitting 3 Ignition timing - checking and adjustment 4 Igrrtion system - check See Chapter 1A Spark plugs - renewal See Chapter 1A
Degrees of difficulty
Easy,
suitable for Falrty easy, sulabte Fafety difficult, suitable for competent Difficult, suitable for Very difficult, ^ novice with littie
1
for beginner with Fafety difficult, suitable for competent experienced DIY suitable for expert DIY or professional ^ expenence 1 some experience DIY mechanic mechanic *
suitable for expert DIY or professional ^
Specifications
General System type
firing order Ignition timing at Idle speed (non-adjustable, for reference onlyy. 6-valve engines: Single-point injection engine with manual transmission .... Single-point injection engine with automatic transmission.. Multi-point injection engine 16-valve engines
Ignition
coil winding resistance (at 20°C): Primary Secondary
Weber-Marelli static (distributorless), wasted spark Ignition system controlled by engine management ECU
1
-3-4-2 (No 1 cylinder at timing belt end of engine)
10® ± 3° BTDC 6° ± 3° STDC 13° ±3° BTDC 8° x 3° BTDC
0.495 to 0.605 ohms 6660 to 8140 Ohms
Page 154 of 225

5B*2 Ignition system - petrol models
1 HT leads 2 Support 3 Cover mounting bdt 4 Ignition coifs
5 Washer 6 Washer 7 Coil mounting bolt
1.2s Ignition coils and HT leads 9 Washer 10 Coil mounting bracket
11
Nut
12 Waslrer 13 Spark plugs 14 Coll cover 15 HT lead support
16 HT lead support 17HTlead support 18 Seat Id Bracket
1 General information
The ignition system is integrated with the fuel injection system to form a combined engine management system under the control of one ECU (see the relevant part of Chapter 4 lor further Information). The Ignition side of the system is of the static (distributorless) type, consisting only of two twin-output Ignition coils located on the left-hand side of the cylinder head. Each ignition coil supplies two cylinders (one coll supplies cylinders 1 and 4, and the other cylinders 2 and 3) (see Illustrations). Under the control of the ECU, the ignition coils operate on the wasted spark principle, ie. each spark plug sparks twice for every cycle of the engine, once on the compression stroke and once on tho exhaust stroke. The spark voltage is greatest in the cylinder which Is under compression, the other cylinder
having a very weak spark which has no effect on the exhaust gases. The ECU uses Its Inputs from the various sensors to calculate the required ignition advance setting and coil chorging time.
1.2b Ignition coll circuit 1 Primary windings 2 Secondary windings 3 Power module
2 Ignition system -testing i
A
Warning: Voltages produced
by
an electronic Ignition system an considerably higher than (hose produced by conventional Ignition systems. Extreme care must be tak»n when working on tho system with thi Ignition switched on. Persons wilfl surgically-implanted cardiac pacemaker devices should keep well clear ot the ignition circuits, components and (oaf equipment 1 If a fault appears In the engine management (fuel injection/ignition) system first ensure that the fault is not due to a poor electrical connection or poor maintenance: ie, checK lhat the air cleaner filter element is clean, tht spark plugs are In good condition and correctly gapped, lhat the engine breather hoses are clear and undamaged, referring to
Page 155 of 225

Ignition system - petrol models 5B®3
Chapter 1A tor further information. Also check tnat tha accelerator cable is correctly adjusted
as
described in the relevant part of Chapter 4. If the engine is running very roughly, check the compression pressures and the valve clearances as descnbed In the relevant parts of Chapters 1 and 2. 2
H
these checks fall to reveal the cause of the problem, the vehicle should be taken to a suitably equipped Fiat dealer for testing. A wiring block connector Is Incorporated in the engine management circuit Into which a special electronic diagnostic tester can be plugged. The tester will locate the fault quickly and simply alleviating the need to test all the system components Individually which is a time consuming operation that carries a high risk of damaging the ECU. 3 The only Ignition system checks which can
oe
earned out by the home mechanic are those cescribed in Chapter 1A, relating to the spark plugs, and the ignition coll test descnbed In this Chapter. If necessary, the system wiring and wiring connectors can oe checked as descnbed in Chapter 12, Section 2, ensuring that the ECU wiring connector(s) have first
been
disconnected.
3 Ignition HT coil - ^ removal, testing and refitting
Removal 1 On 6-valve engines, unscrew the boll and remove the plastic cover from the left-hand
end
of the cylinder head (see Illustration). On 15-valve engines, remove the air cleaner, resonator and Inlet air duct as described in Chapter 4B. 2 Identify the two HT leads for position then disconnect them from the coil HT terminals jsee illustration). 3 Disconnect the LT wiring plug.
4 Unscrew the mounting bolts and remove the relevant ignition coil from the end of the cylinder head,
Testing 5 Testing of the coil consists of using a multimeter set to its resistance function, to check the primary and secondary windings for continuity and resistance. Compare the results obtained to those given In the Specifications at the start of this Chapter. Note the resistance of the coil windings varies slightly according to the coil temperature; the results In the Specifications are approximate values for the coil at 20°C. 6 Check that there is no continuity between the HT lead terminals and the coil body/ mourning bracket. 7 Note that with the ignition switched on and the engine stationary, voltage will only be supplied to the ignition cotls for approx-imately 2 seconds. However, when tho engine is being cranked or running, voltage will be continually supplied. 8 If faulty, the coil should be renewed.
Refitting 9 Refitting ts a reversal of the removal procedure ensuring that the winng and HT leads are correctly reconnected (see illustration).
4 ignition timing • checking and adjustment
1 The Ignition timing is constantly being monitored and adjusted by the engine management ECU, and although it is possible to check the base ignition liming using a standard timing light It is not possible to adjust it. 2 For those wishing to check the ignition timing a stroboscope timing light will be required, and it will need to be the type which
3.1 Removing the ignition coll cover
can determine the amount of advance from the TDC markings on the crankshaft pulley or flywheel. It Is recommended that the timing mark is highlighted as follows. 3 Remove the plug from the top of the transmission then turn tho engine slowly (raise the front right-hand wheel and engage 4th gear) until the timing mark scribed on the edge of the flywheel appears in the aperture. Highlight the line with quick-drying white paint - typist's correction fluid is ideal. 4 Start the engine and run It to normal operating temperature, then stop it. 5 Connect the timing light to No 1 cylinder spark plug lead (No 1 cylinder Is at the timing belt end of the engine) as described in the timing light manufacturer's Instructions. 6 Start the engine, allowing it to idle at the specified speed (Chapter 1A), and point the timing light at the transmission housing aperture. Adjust the timing light until the TDC marks are aligned with each other and read off the amount of advance. 7 If the ignition timing is incorrect, the car should be taken to a Fiat dealer who will be able to check the system quickly using special diagnostic equipment. 8 After making the check stop the engine, disconnect the timing light and refit the plug to the transmission.
3.2 HT terminals (1) and LT wiring plugs (2) on the two ignition colls 3.9 Ignition colt connections
Page 168 of 225

Automatic transmission 7B*3
11 When reverse gear Is selected, the control unit keeps the transmission In tow ratio, if this were not the case, it would, In theory, be possible to drive as fast In reverse as in forward gear. 12 An electronic control unit supplies the current to energise the clutch. The control unit receives signals concerning engine speed, road speed, accelerator pedal position, and gear selector position, Sensors include the following. a) Engine rpm sensor (from the Injection/ignition control unit) b) Accelerator pedal switch
c) Throttle valve position sensor d) Selector lever position sensor e) Vehicle speed sensor f) Coolant temperature sensor g) Air conditioning sensor h) Brake switch I) Torque signal
13 The final drive/differential unit Is conventional. Drive from the driven pulley is transmitted to the differential by an Intermediate reduction gear. 14 The ECVT incorporates a warning light which illuminates when a fault occurs.
Precautions 1$ Observe the following precautions to avoid damage to the automatic transmission: a) Do not attempt to start the engine by pushing or towing the car. b) If the car has to be towed for recovery, the distance must not exceed 12 miles (20
km),
and the speed must not exceed
19
mph
(30 kph).
If these conditions cannot be met, or If transmission damage is suspected, only tow the car with the front wheels clear of the ground. c) Only engage P or R when the vehicle is stationary.
1.1b Electromagnetic f Coil 2 Signal from vehicle speed sensor 3 Transmission 4 Electromagnetic powder 5 Drive shaft (driven by crankshaft) $ Transmission input shaft 7 Electromagnetic clutch housing 8 ECVT control unit
clutch control system 9 Accelerator pedal micro switch 10 Throttle
vafve
opening position potentiometer 11 Multifunction switch 12 Ignition switch
13
Air conditioning
signal
14 Engine PPM
signal
15 Accelerator pedal 16 Coolant temperature signal 17 Injection/ignition control unit 18 8attery
1.1c Hydraulic control system 3 Injection/ignition control unit 4 Air conditioner sensor
signal
6 Coolant temperature signal 7 Clutch signal 8 Engine RPM
signal
9 ECVT warning light 10 Selector lever position 11 Accelerator
pedal
switch/throttle
valve
potentiometer/torque signal 12 Brake switch 13
ECVT
control unit 14 Signal from vehicle speed sensor
15
Accelerator pedal position switch
16 Pulley ratio 17 Input shaft RPM 18 Primary oil pressure
19
Primary pulley 20 Electromagnetic clutch 21 Pressure regulating solenoid valve 22 Oil pressure control valve 23 Secondary oil pressure 24 Slip ring 25 Drive from engine 26 Oil pump 27 Vehicle speed sensor 28 Secondary pulley 29 Belt and pulley 30 Drive to drlveshafts
Page 189 of 225

10*1
Chapter 10
Suspension and steering
Contents
Front hub bearings - renewal 2 Front suspension anti-roll bar • removal and refitting 6 Front suspension lower arm - removal and refitting 4 Front suspension lower arm balljolnt - renewal 5 From suspension strut - removal, overhaul and refitting 3 General information 1 Ignition switch/steering column lock - removal and refitting 10 Manual steering gear assembly - removal, overhaul and refitting ... 12 Power steering fluid level check See Weekly checks Power steering gear assembly - removal and refitting 13 Power steering hydraulic system - bleeding 15
Degrees of difficulty
Power steering pump • removal and refitting 16 Rear hub bearings - renewal 7 Rear suspension components- removal, overhaul and refitting 8 Steering and suspension check See Chapter 1A or 1B Steering column - removal, overhaul and refitting 11 Steering gear rubber gaiters - renewal 14 Steering wheel - removal and refitting 9 Track-rod end - removal and refitting 17 Wheel alignment and steering angles • general information 18 Wheel and tyre maintenance and tyre pressure checks See Weekly checks
Easy, suitable for nowoe with little
Jg experience ^
Fakty easy,
suitable for beginner
with
J£>
some experience
^
FaMy difficult,
% suitable for competent ^
DIY mechanic
^
Difficult,
suitable for & experienced DIY « mechsmc ^
Very difficult,
^ suitable for expert
DIY
fij or professional ^
Specifications
Front suspension Type
Rear suspension Type
Steering Type Turns lock-to-lock: Manual Power assisted Toe setting (front)
Roadwheeis and tyres See Weekly checks
Torque wrench settings Front suspension Anti-roll bar bush bracket bolts Driveshaft nut:' All models except turbo diesel (M22 plain) Turbo diesel (M24 with staking and captive washer) Lower arm balljoint to hub carrier Lower arm front bush securing bolt Lower arm rear bush securing bolt Suspension strut damper nut Suspension strut to hub carrier Suspension strut to inner wing
Independent, incorporating transverse lower wishbones and coil spring-over-teiescopic damper strut units. Anti-roll bar fitted to all models.
Independent, incorporating trailing arms with telescopic dampers and coil springs.
Rack-and-pinlon, manual or power assisted, depending on model
4.4 approx. 2.9 approx. 0° (parallel) ± 1a
Nm ibfft
30 22
240 177 280 207 30 22 95 70 70 52 60 44 70 52 50 37
Page 190 of 225

Suspension and steering 10*2
Torque wrench settings (continued) Nm ibt ft Rasr suspension Damper lower securing bolt 95 70 Damper upper securing bolt 60 44 Handbrake cable support bracket-to-trailing arm screws 15 11 Hub nut 280 207 Trailing arm securing bolt 150 111 Steering Ignition switch/steering column lock securing bolts 4 3 Steering column mounting bolts 55 41 Steering gear mounting bolts 70 52 Steering wheel nut' 50 37 Subframe-to-body bolts 110 81 Track-rod end to hub carrier 40 30 Unlversaijointclampbolts 20 15 Roadwheels Roadwheel bolts 85 63 * Use a new nut
1 General information
Front suspension The front suspension is independent, comprising transverse lower wishbones, coil spring-over-damper strut units and an anti-roll bar. The hub carriors are bolted to the base of the stmt units and are linked to the lower arms by means ot balliotnts. The entire front suspension assembly is mounted on a subframe, which is In turn botted to the vehicle body.
Rear suspension The rear suspension incorporates a torsion beam axle, trailing arms, coil springs and separate telescopic dampers. In addition, a rear anil-roll bar is fitted to certain models. The components form a discrete sub-assembly which can be unboiled from the underside of the vehicle separately or as a complete unit.
Steering The two-piece steering shaft runs in a tubular column assembly, which is bolted to a bracket mounted on the vehicles bulkhead. The shaft Is articulated at its lower end by means of a universal Joint, which is clamped to the steering shaft and the steering gear pinion by moans of clamp bolts. The steering gear is mounted on the engine compartment bulkhead, and is connected to the steering arms projecting rearwards from Ihe hub carriers. The track-rods are fitted with balljoints at their inner and outer ends, to allow for suspension movement, and are threaded to facilitate ad|ustment. Hydrauiically-assisted power steering ts fittod to some models. The hydraulic system is powered by a belt-driven servo pump, which is driven from the crankshaft pulley.
Certain models are fitted with an airbag system. Sensors built into the vehicle body are triggered in the event of a front end collision and prompt an Electronic Control Unll (ECU) to activate the airbag, mounted In the centre of the steering wheel and the facia. This reduces the risk of the front seat occupants striking the steering wheel, windscreen or facia during an accident.
A
Warning: For safety reasons, owners are strongty advised to entrust to an authorised Flat dealer any work which involves disturbing the airbag system components. The airbag inflation devices contain explosive material and legislation exists to control their handling and storage, in addition, specialised test equipment Is needed to check that the airbag system Is fully operational following reassembly.
2 Front hub bearings -renewal *
Note: A balljoint separator tool, and a press or suitable alternative tools (see text) will be required for this operation. The bearing will be destroyed during the removal procedure.
Removal 1 Chock the rear wheels, apply the handbrake, then jack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). Remove the appropriate roadwheel. 2 Remove the brake disc and caliper, with reference to Chapter 9. Note that the caliper body can remain bolted to its bracket: there is no need lo disconnect the brake fluid hose from the caliper. 3 With reference to Chapter 8. slacken and remove the driveshaft hub nut. 4 On models with ABS, unbolt the ABS wheel sensor, and remove the screw securing the
ABS sensor wiring to the hub carrier. Suspend the sensor away from the working ares, to avoid the possibility of damage. 5 With reference to Section 17, separate
th»
track-rod end from the hub carrier, using
a
suitable balljoint splitter. 6 Remove the two nuts from tho botts securing Ihe hub carrier to the base of th» suspension strut (refer to Section
3).
Withdrew the bolts and separate the top of hub earrtt from the strut. 7 Disconnect the outboard end of Ito driveshaft from the hub, as described durirg the driveshaft removal and refitting procedm in Chapter 8. Note: There is no naod fo disconnect the Inboard end of the
drivestett
from the transmission. Caution: Do not allow the end of tin driveshaft to hang down under its
own
weight, as this places strain on the
CV
joints; support the end of the shaft uskg wire or string. 8 Slacken and remove the nut and clamp bolt, then push the lower arm down anc separate the balljoint from the base of the tab carrier (see illustrations). 9 At this stage, it is recommended that
the bub
carrier be taken to a engineering workshop,
as
the hub and bearing should ideally be removed from the hub carrier using a hydraulic press
2.8a ... Slacken and remove the nut...
Page 196 of 225

Suspension and steering 10*8
9.1 Prise the horn centre pad from the steering wheel hub unbolt the lower end of the damper from the trailing arm. 9 Lower the trailing arm gradually using a trolley jack, until the coil spring Is released from its lower seat on the trailing arm and its upper seat on the subframe. Make a note of the orientation of the coll spring, to aid correct refitting later. Refitting 10 Refitting is a reversal of removal, lighten the damper lower retaining bolt to the specified torque. Trailing arm Note: The rear stub axles are integral with the trailing arm assemblies and cannot be renewed separately. Removal 11 With reference to Chapter 9. carry out the following: a) Remove the brake drum, shoes and adjuster assembly. b) Unbolt the brake hose union from the
rear
of the wheel cylinder. c) Unbolt the brake pipe mounting bracket from the trailing arm. 12 Refer to Section 7 and remove The rear hub and beanng assembly. 13 With reference to the relevant sub-Section, unbolt the lower end of Ihe damper from the trailing arm. 14 Raise the trailing arm using a trolley jack so that the coll spring Is compressed, then slacken and withdraw the trailing arm front mounting bolL 15 With reference to the previous sub-Section, gradually lower the trailing arm using a trolley lack and remove the coll spring. 16 Allow Ihe trailing arm to hang down, then pull the leading edge of the arm down from its mounting bracket. Refitting 17 Refitting Is a reversal of removal. Tighten all suspension fixings to the specified torque settings, but delay this operation until the full weight vehicle is resting on the roadwheeis -this prevents the damper and trailing arm bushes from being strained. 18 On completion, bleed the brake hydraulic system and adjust the operation of the handbrake, with reference to Chapter 9.
9.2 Unplug the wiring from the centre pad at the connector(s)
9 Steering wheel - % removal and refitting ^
Note: This procedure does not apply to vehicles fitted with an airbag A Warning: For safety reasons, owners are strongly advisod to entrust to an authorised Fiat dealer any work which involves disturbing the airbeg system components. The airbag inflation devices contain explosive material and legislation exists to control their handling and storage. In addition, specialised test equipment Is needed to check thet the alrbag system Is fully operational following reassembly.
Removal 1 Ensure that the ignition is switched off, then prise the horn centre pad from the steering wheel hub. Use the blade of a screwdriver, padded with PVC tape to protect the steering wheel (see illustration) 2 Unplug the horn and (where applicable) radio/cassette control switch wiring from the centre pad at the connectors) (see illustration) 3 Turn the steering wheel to its centre position, so that the roadwheeis are pointing straight ahead. 4 Make alignment marks between the steering wheel and the end of the steering column shaft, to aid correct refitting later, 5 Relieve the staking and then slacken and remove tne steenng wheel securing nut (see
9.5 Slacken and remove the steering wheel securing nut Illustration). Discard the nut as a new item must used on refitting. 6 Lift the steering wheel off the column splines. If it is tight, tap il near the centre, usrg the palm of your hand, or twist it from
side to
side, whilst pulling upwards to release il ton the shaft splines. If the wheel is particular tight, a suitable puller should be used.
Refitting 7 Before commencing refitting, lightly eca. Ihe surfaces of the direction indicator cancelling mechanism with grease. 8 Refitting is a reversal of ren>oval.
bearing a
mind the following points: a) Use a new steering wheel
securing not
and tighten it to the specified
torque.
Ensure that its outer collar
Is adequate^
staked to the column shaft
using a
hammer and punch (see Illustrations). b) Ensure that the direction Indicator
swiith
is in the central (cancelled/off)
position,
otherv/ise the sivitch may be damaged X the wheel Is refitted. c) Align the marks made on the
wheel and
Ihe steering column shaft during removeI 9 Note that if necessary, the position of tf* steering wheel on the column shaft cant* | altered in order to centralise the wheel (enstn that the front roadwheeis aro pointing
In the
straight-ahead position), by moving the vMti the required number of splines on the
sfcafc
Fine adjustment can be carried out by adjusting the length of both track-rwa simultaneously, but this operation is best entrusted to a Rat dealer or tyre specialist
9.8a Fit a new steering wheet securing nut... 9.3b ... and stake it to the steering column shaft using o hammer and punch