1997 FIAT PUNTO Pression

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

11 *2 Bodywork and fittings
on vehicles with wax-based underbody protective coating, or the coating will be removed. Such vehicles should be inspected annually, preferably just prior lo Winter, when the underbody should be washed down, and any damage to the wax coating repaired. Ideally, a completely fresh coat should be applied. It would also be worth considering the use of such wax-based protection for injection into door panels, sills, box sections, etc, as an additional safeguard against rust damage, where such protection Is not provided by the vehicle manufacturer. After washing paintwork, wipe off with a chamois feather to give an unspotted clear finish. A coat of clear protective wax polish wilt give added protection against chemical pollutants in the air. If the paintwork sheen has duiled or oxidised, use a cleaner/polisher combination to restore the brilliance of the shine. This requires a little effort, but such dulling Is usually caused because regular washing has been neglected. Care needs to be taken with metallic paintwork, as special non-abrasive cleaner/polisher is required to avoid damage to the finish, Always check that the door and ventilator opening drain holes and pipes are completely clear, so that water can be drained out. Brightwork should be treated In the same way as paintwork. Windscreens and windows can be kept clear of the smeary film which often appears, by the use of proprietary glass cleaner. Nover use any form of wax or other body or chromium polish on glass.
Maintenance -upholstery and carpets
Mats and carpets should be brushed or vacuum-cleaned regularly, to keep them free of grit. If they are badly stained, remove them from the vehicle for scrubbing or sponging, and make quite sure they are dry before refitting. Seats and interior trim panels can be kept clean by wiping with a damp cloth. If they do become stained (which can be more apparent on light-coloured upholstery), use a little liquid detergent and a soft nail brush lo scour the grime out of the grain of the material. Do not forget to keep the headlining clean in the same way as the upholstery. When using liquid cleaners inside the vehicle, do not over-wet the surfaces being cleaned. Excessive damp could get Into the seams and padded interior, causing stains, offensive odours or even rot.
If the Inside of the vehicle gets wet accidentally, tt Is worthwhile taking some trouble to dry ft out property, particularly where carpets an involved. Do not leave oil or electric heaters inside the vehicle for this purpose.
4 Minor body damage -repair
Repairs of minor scratches In bodywork If the scratch Is very superficial, and does not penetrate to the metal of the bodywork, repair is very simple. Lightly rub the area of the scratch with a paintwork renovator, or a very fine cutting paste, to remove loose paint from the scratch, and to clear the surrounding bodywork of wax polish, Rinse the area with clean water. Apply touch-up paint to ihe scratch using a fine paint brush; continue to apply fine layers of paint until the surface of the paint In the scratch Is level with the surrounding paintwork. Allow Ihe new paint at least two weeks to harden, then blend it Into the surrounding paintwork by rubbing the scratch area with a paintwork renovator or a very fine cutting paste. Finally, apply wax polish. Where the scratch has penetrated right through to the metal of the bodywork, causing the metal to rust, a different repair technique Is required. Remove any loose rust from the bottom of the scratch with a penknife, then apply rust-inhibiting paint to prevent the formation of rust in the future. Using a rubber or nylon applicator, fill the scratch with bodystopper paste. If required, this paste can be mixed with cellulose thinners to provide a very thin paste which is ideal for filling narrow scratches. Before the stopper-paste in Ihe scratch hardens, wrap a piece of smooth cotton rag around the top of a finger. Dip the finger in cellulose thinners, and quickly sweep it across the surface of the stopper-paste in the scratch: this will ensure that the surface of the stopper-paste is slightly hollowed. The scratch can now be painted over as described earlier In this Section.
Repairs of dents in bodywork When deop denting of the vehicle's bodywork has taken place, the first task is to put) the dent out. until the affected bodywork almost attains rts onginal shape. There is little polnl in trying to restore Ihe original shape completely, as the metal in the damaged area will have stretched on impact, and cannot be reshaped fully to its original contour. It Is better to bring the level of the dent up to a point which is about 3 mm below the level of the surrounding bodywork. In cases where Ihe dent is very shallow anyway, It is not worth trying to pull it out at all. If the underside of the dent is accessible, it can be hammered out gently from behind, using a mallet with a wooden or plastic head, Whilst doing this, hold a suitable block of wood firmly against (he outside of Ihe panel, to absorb the impact from the hammer blows and thus prevent a large area of the bodywork from being 'belled-out".
Should the dent be In a section of (I* bodywork which has a double skin, or seme other factor making It Inaccessible from behind, a different technique is called for. Dull several small holes through the metal inside Ihe area - particularly in the deeper section. Then screw long self-tapping screws Into the holes, just sufficiently for them to gain a good purchase in the metal. Now the dent can be pulled out by pulling on the protruding heads of the screws with a pair of pliers. The next stage of the repair Is the removal of the paint from the damaged area, and from an inch or so of the surrounding 'sound' bodywork. This is accomplished most easily by using a wire brush or abrasive pad on a posver drill, although it can be done just as effectively by hand, using sheets of abrasive paper. To complete the preparation for filling, score the surface of the bare metal wflhi screwdriver or the tang of 8 file, or alternatively, drill small holes In the affected area. This will provide a really good 'key' for the filler paste. To complete the repair, see the Section on filling and respraying.
Repairs of rust holes or gashes in bodywork Remove all paint from the affected area, and from an inch or so of the surrounding 'sound' bodywork, using an abrasive pad
or a
wire brush on a power drill. If these are not available, a few sheets of abrasive paper wil do the job most effectively. With the paint removed, you will be able to judge the severity of the corrosion, and therefore decide whether to renew the whole panel (if this is possible) or to repair the affected area. New body panels are not as expansive as most people think, and it is often quicker and more satisfactory to fit a new panel than to attempt to repair large areas of corrosion. Remove all fittings from Ihe affected area, except those which will act as a guide to ttie original shape of the damaged bodywork (eg headlight shells etc). Then, using tin snips
or a
hacksaw blade, remove all loose metal snd any other metal badly affected by corrosion. Hammer the edges of the hole inwards, in order to create a slight depression for the filer paste. Wire-brush the affected area to remove tha powdery rust from the surface of the remaining metal. Paint Ihe affected area with rust-inhibiting paint, if the beck of the rusted area is accessible, treat this also. Before filling can take place, ft will be necessary to block the hole in some
way.
TNs can be achieved by the use of aluminium cr plastic mesh, or aluminium tape. Aluminium or plastic mesh, or glass-fibre matting, is probably the best material to use for a large hole. Cut a piece to tha approximate size and shape of tho hole to b« 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