1997 FIAT PUNTO Circuit

Safety first! 0.5
Working on your ear can be dangerous. This page shows just some of the potential risks and hazards, with the aim of creating a safety-conscious attitude.
General hazards
Scalding • Don't remove the radiator or expansion tank cap while the engine is hot. • Engine oil, automatic transmission fluid or power steering fluid may also be dangerously hot if the engine has recently been running.
Burning • Beware of burns from the exhau3t system and from any part of the engine. Brake discs and drums can also be extremely hot immediately after use.
Crushing • When working under or near a raised vehicle. ~ always supplement the ' ' -jack with axle stands, or use ... drive-on i'j ramps. kr Never venture ™ under
a
car
vv/j/ch
Is only supported by a jack. • Take card if loosening or tightening high-torque nuts when the vehicle is on stands. Initial loosening and final tightening should be done with the wheels on the ground.
Fire • Fuel Is highly flammable; fuel vapour is explosive. • Don't (et fuel spill onto a hot engine. • Do not smoke or allow naked lights (including pilot lights) anywhere near a vehicle being worked on. Also beware of creating sparks (electrically or by use of toots). • Fuel vapour is heavier than air, so don't work on the fuel system with the vehicle over an inspection pit. • Another cause of fire is an electrical overload or short-circuit. Take care when repainng or modifying the vehicle wiring. • Keep a fire extinguisher handy, of a type suitable for use on fuel and electrical fires.
Electric shock x ^ ^ ? , • Ignition HT _ " voltage can be ^ dangerous, ~ especially to > people with heart problems or a pacemaker. Don't work on or near the f^ ignition system with fT") the engine running or ' J ' J the Ignition switched on.
• Mains voltage is also dangerous. Make sure that any mains-operated equipment is correctly earthed. Mains power points should be protected by a residual current device (RCD) circuit breaker.
Fume or gas intoxication • Exhaust fumes are poisonous: they often contain carbon monoxide, which is rapidly fatal if inhaled. Never run the engine in a confined space such as a garage with the doors shut, • Fuel vapour is also poisonous, as are the vapours from some cleaning solvents and paint thinners.
Poisonous or irritant substances • Avoid skin contact with battery acid and with any fuel, fluid or lubricant, especially antifreeze, brake hydraulic fluid and Diesel fuel. Don't syphon them by mouth. If such a substance is swallowed or gets into the eyes, seek medical advice. « Prolonged contact with used engine oil can cause skin cancer. Wear gloves or use a barrier cream If necessary. Change out of oll-soaked clothes and do not keep oily rags in your pocket. • Air conditioning refrigerant forms a poisonous gas if exposed to a naked flame {including a cigarette). It can also cause skin burns on contact.
Asbestos • Asbestos dust can cause cancer if inhaled or swallowed. Asbestos may be found In gaskets and in brake and clutch linings. When dealing with soch components It is safest to assume that they contain asbestos.
Special hazards
Hydrofluoric acid • This extremely corrosive acid is formed when cerlam types of synthetic rubber, found In some O-rings, oil seals, fuel hoses etc. are exposed to temperatures above 400;C. The rubber changes into a charred or sticky substance containing the acid. Once formed, the acid remains dangerous for years, tfit gets onto the skin, it may be necessary to amputate the limb concerned. • When dealing with a vehicle which has suffered a fire, or with components salvaged from such a vehicle, wear protective gloves and discard them after use.
The battery • Batteries contain sulphuric acid, which attacks clothing, eyes and skin. Take care when topping-up or carrying the battery. • The hydrogen gas given off by the battery is highly explosive. Never cause a spark or allow a naked light nearby. Be careful when connecting and disconnecting battery chargers or jump leads.
Air bags • Air bags can cause injury if they go off accidentally. Take care when removing the steenng wheel and/or facia. Special storage instructions may apply.
Diesel injection equipment • Diesel injection pumps supply fuel at very high pressure. Take care when working on the fuel injectors and fuel pipes.

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Warning: Never expose the hands, face or any otfterpart of the body to injector spray; the fuel can penetrate the skin with potentially fatal results.
Remember...
DO • Do use eye protection when using power tools, and when working under the vehicle. • Do wear gloves or use barrier cream to protect your hands when necessary. • Do get someone to check periodically that all is well when working alone on the vehicle. • Do keep loose clothing and long hair well out of the way of moving mechanical parts. • Do remove rings, wrtstwatch etc. before working on the vehicle - especially the electrical system, • Do ensure that any lifting or jacking equipment has a safe working load rating adequate for the job.
DON'T • Don't attempt to lift a heavy component which may be beyond your capability - get assistance. • Don't rush to finish a job. or take unverified short cuts. • Don't use ill-fitting toots which may slip and cause injury. • Don't leave tools or parts lying around where someone can trip over them. Mop up oil and fuel spills at once. • Don't allow children or pets to play In or near a vehicle being worked on.

o«i6 Weekly checks
Battery
Caution: Before carrying out any work on the vehicle battery, read the precautions given In "Safety first" at the start of this manual. • Make sure thai the battery tray is in good condition, and that the clamp Is tight. Coirosion on the tray, retaining clomp and the battery itself can be removed with a solution of water and baking soda, Thoroughly rinse all cleaned areas with water. Any metal parts damaged by corrosion should be covered with a zinc-based primer, then painted. • Periodically (approximately every three months), check the charge condition of the battery as described In Chapter SA. • If the battery Is flat, and you need to jump start your vehicle, see Roadside Repalrz.
Battery corrosion can be kept to a minimum by applying o layer of petroleum Jelly to the clamps and terminals after they are reconnected
fin %

I

The battery is located on the left-hand side of the engine compartment, The exterior of the battery should be inspected penodlcaily for damage such as a cracked case or cover.

2

Check the tightness of battery clamps (A) to ensure good electrical connections. You should not be able to move them. Also check each cable (B) for cracks and frayed conductors.

3

If corrosion (while, fluffy deposits) is evident, remove the cables from the battery terminals, clean them with a small wire brush, then refit them. Automotive stores sell a tool for cleaning the battery post...
as well as the battery cable clamps
Electrical systems
• Check all external lights and the horn. Refer to the appropriate Sections of Chapter 12 for details if any of the circuits are found to be Inoperative,
• Visually chock all accessible wiring connectors, harnesses and retaining clips for security, and for signs of chafing or damage.
fffjffflg^ " y°u A**^ check your "T™*! broke lights and Indicators ,HllMT[ unaided, back up to a wall or garage door and operate the lights. The reflected light shouid show
If
they are working property.

I

I? a single indicator light, stop-light or headlight has failed, it Is likely that a bulb has blown and will need to be replaced. Refer to Chapter 12 for details. If both stop-lights have failed, it is passible that the switch has failed (see Chapter 9).

2

If more than one Indicator light or tail light has failed It is likely that either a fuse has blown or that there is a fault tn the circuit (see Chapter 12). The fuses are located behind the oddments tray on ihe facia. First unscrew the two screws and swivel Ihe tray down.

3

To replace a blown fuse, simply pull it out using the special plastic tool and fit a new fuse of tho correct rating (see Chapter 12). If the fuse blows again, it is importont that you find out why - a complete checking procedure Is given in Chapter 12.

Every 20 000 miles - petrol models 1A.13
20 Ignition system check
81
21 Engine management system check

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Warning: Voltages produced by an electronic ignition system are considerably higher than those produced by conventional ignition systems. Extreme care must be taken when working on the system with the Ignition switched on. Persons with surgically-Implanted cardiac pacemaker devices should keep well clear of the ignition circuits, components and test oquipment. 1 The ignition system components should be checked for damage or deterioration as follows.
General component check 2 The spark plug (HT) leads should be checked whenever new spark plugs are fitted. 3 Pull the leads from the plugs by gripping
the end
fitting, not the lead, otherwise the lead connection may be fractured.
Ensure that the leads are i numbered before removing i them, to avoid confusion when refitting
4 Check Inside the end fitting for signs of corrosion, which will look like a white crusty powder. Push the end fitting back onto the spark plug, ensuring that it is a tight fit on the plug. if not, remove the lead again and use pliers to carefully crimp the metal connector inside the end fitting until it fits securely on the
end
of the spark plug. 5 Using a clean rag, wipe Ihe emlre length of the lead to remove any built-up dirt and grease. Once the lead is clean, check for bums, cracks and other damage. Do not bend the lead excessively, nor pull the lead lengthways - the conductor inside might break. 6 Disconnect the other end of the lead from the ignition coll. Again, pull only on the end fitting. Check for corrosion and a tight fit in the
same
manner as the spark plug end. Refit the bad securely on completion. 7 Check the remaining leads one at a time, in
ihe same
way. 8 if new spark plug (HT) leads are required, purchase a set for your specific car and engine. 9 Even with the ignition system In first-class condition, some engines may still occasionally experience poor starting attributable to damp ignition components. To disperse moisture, a water-dispersant aerosol should be liberally
Ignition timing -
check
and adjustment 10 Check the ignition timing as described In Chapter 58.
1 This check is part of the manufacturer's maintenance schedule, and Involves testing Ihe engine management system using special dedicated test equipment. Such testing will allow the test equipment to read any fault codes stored in the electronic control unit memory. 2 Unless a fault is suspected, this test te not essential, although it should be noted that it is recommended by the manufacturers. 3 If access to suitable test equipment is not possible, make a thorough check of all ignition, fuel and emission control system components, hoses, and wiring, for security and obvious signs of damage. Further details of the fuet system, emission control system and ignition system can be .found In the relevant parts of Chapters 4 and 5.
22 Hinge and lock lubrication %
1
1 Lubricate the hinges of the bonnet, doors and tailgate with a light general-purpose oil. Similarly, lubricate ail latches, locks and lock strikers. At the same time, check the security and operation of all the locks, adjusting them If necessary (see Chapter 11). 2 Lightly lubricate the bonnet release mechanism and cable with a suitable grease.
23 Headlight beam adjustment % & ^
1 Accurate adjustment of the headlight beam is only possible using optical beem-setting equipment, and this work should therefore be carried out by a Fiat dealer or service station with the necessary facilities. In an emergency, however, the following procedure will provide an acceptable light pattern. 2 Position the car on a level surface with tyres correctly inflated, approximately 10 metres in front of. and at right-angles to, a wall or garage door, 3 Draw a horizontal line on the wall or door at headlamp centre height. Draw a vertical line corresponding to the centre line of the car, then measure off a point either side of this, on the horizontal line, corresponding with the headlamp centres. 4 Switch on the main beam and check that the areas of maximum illumination coincide with the headlamp centre marfcs on Ihe wall, if not. turn the adjustment screw located on the upper inside edge of the headlight unit to adjust the beam laterally, and the adjustment screw located on the upper outside edge of the headlight unit to adjust the beam
vertically. On models with electric headlight adjustment, make sure that it is set at its basic setting before making the adjustment.
24 Road test
Instruments and electrical equipment 1 Check the operation of all Instruments and electrical equipment. 2 Make sure that all instruments read correctly, and switch on all electrical equipment in turn, to check that it functions properly.
Steering and suspension 3 Check for any abnormalities in the steering, suspension, handling or road feel. 4 Drive the vehicle, and check that there are no unusual vibrations or noises. 5 Check that the steering feels positive, with no excessive sloppiness, or roughness, and check for any suspension noises when cornering and driving over bumps.
Drivetrain 6 Check the performance of the engine, clutch (where applicable), transmission and driveshafts. 7 Listen for any unusual noises from the engine, clutch and gearbox/transmission. 8 Make sure that the engine runs smoothly when Idling, and that there Is no hesitation when accelerating. 9 Check that, where applicable, the clutch action Is smooth and progressive, that the drive is taken up smoothly, and that the pedal travel is not excessive. Also listen for any noises when the clutch pedal is depressed. 10 On manual gearbox models, check that all gears can be engaged smoothly without noise, and that the gear lever action is not abnormally vsgue or notchy. 11 On automatic transmission models, check that all Ihe gear positions can be selected with the vehicle at rest, if any problems are found, they should be referred to a Flat dealer. 12 Listen for a metallic clicking sound from the front of the vehicle, as the vehicle is driven slowly in a circle with the steering on full-lock. Carry out this check in both directions. If a clicking noise is heard, this Indicates wear in a drtveshaft joint, In which case renew the joint if necessary.
Check the braking system 13 Make sure that the vehicle does not pull to one side when braking, and that the wheels do not lock prematurely when braking hard. 14 Check that there is no vibration through the steering when braking. 15 Check that the handbrake operates correctly without excessive movement of the lever, and that It holds the vehicle stationary on a slope.

Every 2 years - petrol models ia.i?
check, and if necessary top-up, the level in the expansion tank. Refit the cap on completion. Antifreeze mixture 22 The antifreeze should always be renewed at the specified Intervals. This is necessary not only to maintain the antifreeze properties, but also to prevent corrosion which would otherwise occur as the corrosion inhibitors
beoome
progressively less effective. 23 Always use an ethylene-glycol based antifreeze which Is suitable for use In mixed-metal cooling systems, The quantity of antifreeze and levels of protection are
Indicated In
the Specifications. 24 8efore adding antifreeze, the cooling system should be completely drained, preferably flushed, and all hoses checked for condition and security. 25 After filling with antifreeze, a label should
be attached
to the expansion tank, stating the type and concentration of antifreeze used, and the date installed. Any subsequent lopping-up should be made with the same
type and
concentration of antifreeze. 26 Do not use engine antifreeze In the windscreen/tailgate washer system, as it will
cause damage to the vehicle paintwork. A screenwash additive should be added to the washer system in the quantities stated on the bottle.
34 Brake fluid renewal | I

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Warning: Brake hydraulic fluid can harm your eyes and damage painted surfaces, so use extreme caution when handling and pouring H. Do not use fluid that has been standing open for some t/me, as it absorbs moisture from the air. excess moisture can cause a dangerous ioss of braking effectiveness. 1 The procedure is similar to that for the bleeding of the hydraulic system as described in Chapter 9, except that the brake fluid reservoir should be emptied by siphoning, using a clean poultry baster or similar before starting, and allowance should be made for the old fluid to be expelled when bleeding a section of the circuit. 2 Working as described In Chapter 9, open the first bleed screw in the sequence, and
pump the brake pedal gently until nearly all the old fluid has bsen emptied from the master cylinder reservoir.
Old hydraulic fluid Is Invariably much darker In colour than the new, making It easy to distinguish the two.
3 Top-up to the MAX level with new fluid, and continue pumping until onty the new fluid remans in the reservoir, and new fluid can be seen emerging from the bleed screw. Tighten the screw, and top the reservoir level up to the MAX level line. 4 Work through all the remaining bleed screws in the sequence until new fluid can be seen at all of them. Be careful to keep the master cylinder reservoir topped-up to above the MIN level et all times, or air may enter the system and greatly increase the length of the task. 5 When the operation Is complete, check that all bleed screws are securely tightened, and that their dust caps are refitted. Wash off all traces of spilt fluid, and recheck the master cylinder reservoir fluid level. 6 Check the operation of the brakes before taking the car on the road.
1A

ib.14 Every 2 years - diesel models
Radiator flushing 7 To flush the radiator disconnect the top and bottom hoses and any other relevant hoses from the radiator, with reference to Chapter 3. 8 Insert a garden hose into the radiator top inlet. Direct a flow of dean water through the radiator, and continue Hushing until clean water emerges from the radiator bottom outlet. 9 II after a reasonable period, the water still does not run clear, the radiator can be flushed with a good proprietary cooling system cleaning agent. It is important that their manufacturer's instructions are followed carefully. If Ihe contamination is particularly bad, insert the hose in the radiator bottom outlet, and reverse-flush the radiator.
Engine flushing 10 To flush tho engine, remove the thermostat as described in Chapter 3. 11 With the bottom hose disconnected, direct a clean flow of water through the engine, and continue Hushing until clean water emerges from the radiator bottom hose. 12 On completion of flushing, refit the thermostat and reconnect the hose with reference to Chapter 3.
Cooling system filling 13 Before attempting to fill the cooling system, make sure that all hoses and clips are in good condition, and that the clips are tight. Note that an antifreeze mixture must be used all year round, to prevent corrosion of the engine components (see following sub* Section). 14 Remove the expansion tank filler cap. and fill the system by slowly pouring the coolant Into Ihe expansion tank to prevent airlocks from forming. Ensure that all bleed plugs/screws are open. 15 If the coolant is being renewed, begin by pouring in a couple of litres of water, followed by the correct quantity of antifreeze, then top* up with more water. 18 Once ihe level in the expansion tank starts to rise, squeeze the radiator top and bottom hoses to help expel any trapped air in
the system. Once all the air is expelled, top-up the coolant level to the MAX mark and refit the expansion tank cap. Close all bleed plugs. 17 Start Ihe engine and run il until it reaches normal operating temperature, then stop the engine and allow It to cool. 18 Check for leaks, particularly around disturbed components. Check the coolant level In the expansion tank, and top-up if necessary. Note that the system must be cold before an accurate level Is indicated In the expansion tank. If the expansion tank cap Is removed while the engine is still warm, cover the cap with a thick cloth, and unscrew the cap slowly to gradually relieve the system pressure (a hissing sound will normally be heard). Wait until any pressure remaining in the system Is released, then continue to turn the cap untH it can be removed.
Antifreeze mixture 19 The antifreeze should always be renewed at the specified intervals. This is necessary not only to maintain the antifreeze properties, but also to prevent corrosion which would otherwise occur as the corrosion Inhibitors become progressively less effective. 20 Always use an ethylene-glycol based antifreeze which is suitable for use in mixed-metal cooling systems. The quantity of antifreeze and levels of protection are indicated in the Specifications. 21 Before adding antifreeze, the cooling system should be complelely drained, preferably flushed, and all hoses checked for condition and security. 22 After filling with antifreeze, a label should be attached to the expansion tank, stating the type and concentration of antifreeze used, and the dale installed. Any subsequent topping-up should bs made with the same type and concentration of antifreeze. 23 Do not use engine antifreeze In the windscreen/tailgate washer system, as it will cause damage to the vehicle paintwork. A screenwash additive should be added to the washer system in the quantities stated on the bottle.
28 Brake fluid renewal

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Warning: Brake hydraulic fluid can harm your eyas and damage painted surfaces, so use extreme caution when handling and pouring It. Do not use fluid that has been standing open for some time, as It absorbs moisture from the air. Excess moisture can causa a dangerous loss of braking effectiveness. 1 The procedure is similar to that for the bleeding of the hydraulic system as described In Chapter 9. except that the brake fluid reservoir should be emptied by siphoning, using a clean poultry baster or similar before starting, and allowance should be made for the old fluid to be expelled when bleeding a section of the circuit. 2 Working as described in Chapter 9, open Ihe first bleed screw in the sequence, and pump the brake pedal gently until nearly all the old fluid has been emptied from the master cylinder reservoir.
ffffTOgf Old hydraulic fluid Is
lifcjllitt*
Invariably much darker In [HINT] colour than the new, making /{easy to distinguish the two.
3 Top-up to the MAX level with new fluid, and continue pumping until only the new fluid remains in the reservoir, and new fluid can be seen emerging from (he bleed screw. Tighten the screw, and top the reservoir level up to Ihe MAX level line. 4 Work through all the remaining bleed screws In the sequence until new fluid can be seen al all of them. Be careful to keep the master cylinder reservoir topped-up 10 above the MIN level al all limes, or air may enter the system and greatly increase the length of the task. 5 When the operation is complete, check thai all bleed screws are securely tightened, and that their dust caps are refitted. Wash off ail traces of split fluid, and recheck the master cylinder reservoir fluid level. 6 Check the operation of the brakes before taking the car on the road,

3*2 Cooling, heating and ventilation systems
essential that you entrust this task to your Flat dealer or a refrlgeralion engineer.

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Warning: The refrigeration circuit contains a liquid refrigerant and
H
Is dangerous to disconnect any part of the system without specialist knowledge and equipment. The refrigerant is potentially dangerous, and should only be handled by qualified persons. If it is splashed onto tha skin, It can cause severe frostbite, tt Is not Itself poisonous, but In the presence of a naked flame (Including a cigarette), it forms a
poisonous gas. Uncontrolled discharging of the refrigerant is dangerous and potentially damaging to the environment.
10 Air conditioning components ^S - removal and refitting J
Note: Do not operate the air conditioning system If it is known to be short of refrigerant, as this may damage the compressor. 1 The only operation which can be carried
out easily without discharging the refrigerant is renewal of the auxiliary (compressor) drivebelt - this procedure Is described in Chapter 1A or 1B. All other operations must be referred to a Fiat dealer or an air conditioning specialist. 2 If necessary for access to other com-ponents, the compressor can be unbolted and moved aside, without disconnecting its flexible hoses, after removing the drivebelt.

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Warning: Do not attempt to open the refrigerant circuit. Refer to
the
precautions given in Section 9.
expert22 a/ia http://rutracker.org

4A*2 Fuel system - single-point petrol Injection models
1 The luel system referred to In this Section is defined as the tank-mounted fuel pump, the fuel litter, the throttle body and pressure regulator components, and the metal pipes and flexible hoses of the fuel lines between these components. All ihese contain fuel which will be under pressure while the engine Is running and/or while tha Ignition is switched on. The pressure will remain for some time after tho ignition has been switched off, and must be relieved before any of these components are disturbed (or servicing work. 2 Disconnect the battery negative terminal (refer to D/sconnecf/ngr the battery in the Reference Section of this manual), 3 Place a container beneath the relevant connection/union to be disconnected, and have a large rag ready to soak up any escaping fuel not being caught by the container. 4 Slowly loosen the connection or union nut (as applicable) to avoid a sudden release of pressure, and wrap tho rag around the connection to catch any fuel spray which may be expelled. Once the pressure is released, disconnect the fuel line, and Insert plugs to minimise fuel loss and prevent the entry of dirt Into the fuel system.
9 Inlet manifold -removal and refitting ^
Note: Refer to the warning given In Section 1 before proceeding.
Removal 1 Remove the throttle body assembly as described in Section 5. 2 Drain the cooling system as described in Chapter 1A. 3 Disconnect the winng connector from the coolanl temperature sensor (situated on the left-hand sidB of the manifold). 4 Undo the bolt securing the accelerator cable mounting bracket to the manifold, and position it clear of the manifold. 5 Slacken the retaining clip and disconnect tha coolant hose from the rear of the manifold. 6 Disconnect the brake vacuum hose. 7 Undo the seven manifold retaining nuts and
10.2 The diagnostic connector la located behind the ECU bolts, and remove (he manifold from the engine. Remove the gasket and discard It; a new one should be used on refitting.
Refitting 8 Refitting is a reverse of the removal procedure, noting the following points: a) Ensure that the manifold and cylinder head mating surfaces are clean and dry, and fit a nev/ manifold gasket. Refit the manifold and securely tighten Its retaining nuts. b) Ensure that all relevant hoses are reconnected fo their original positions and are securely held (where necessary) by the retaining clips. c) Refit the throttle body assembly with reference to Section S. d) On completion, refill the cooling system as described In Chapter 1A.
correctly adjusted, and that the engine breather hoses are clear and undamaged. 2 If 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 connector is situated behind the ECU (see Illustration). 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.
Adjustments 3 As mentioned above, the idle speed and mixture adjustment are all monitored and controlled by the ECU, and are not adjustable Experienced home mechanics with a considerable amount of skill and equipment (including a good-quality tachometer and a good-quality, carefully calibrated exhaust gas analyser) may be able to check the exhaust CO level and ihe idle speed. However, If thes* are found lo be in need of adjustment, the car must be taken to a suitably-equipped Flat dealer for testing using the special test equipment which is plugged into the diagnostic connector.
11 Unleaded petrol -general Information and usage
10 Fuel injection system - & testing and adjustment S
Testing 1 If a fault appears in the fuel injection system, first ensure that all the system winng connectors are securely connected and free of corrosion. Then ensure that the fault Is not due to poor maintenance; ie, check that the air cleanor fitter element is clean, the spark plugs are In good condition and correctly gapped, that tho valve clearances are
Note: The information given in this Chapter
is
correct at the time of writing. If updated Information is thought to be required, check with a Fiat dealer. If travelling abroad, consult one of the motonng organisations (or a similar authority) for advice on the fuel available. 1 All petrol models are fitted with a catalytic converter and must be run on unleaded fuel only - the fuel recommended by Flat is given In the Specifications of this Chapter. Under no circumstances should leaded fuei (UK 4-slar) be used, as this may damage the converter. 2 Super unleaded petrol (98 octane) can also be used in all models if wished, though there is no advantage in doing so.

Fuel system - diesel models 4C*3
14.6 Nuts securing the exhaust downpipe to the exhaust manifold 14.8 Disconnecting the oil return pipe from tho turbocharger
13 Turbocharger -description and precautions
Description A turbocharger 1$ fitted to TDS, TD and SX models. It increases engine efficiency by raising the pressure In the inlet manifold above atmospheric pressure. Instead of the air simply being sucked Into the cylinders. It Is forced in. Additional fuel is supplied by the injection pump in proportion to the increased air inlet. Energy for the operation of the turbocharger comes from the exhaust gas. The gas flows through a specially-shaped housing (the turbine housing) and In so doing, spins the turbine wheel. The turbine wheel is attached lo a shaft, at the end of which is another vaned wheel known as the compressor wheel, The compressor wheel spins in Its own housing, snd compresses the inlet air on the way to the inlet manifold. Boost pressure (the pressure in the Inlet manifold) is limited by a wastegate, which diverts Ihe exhaust gas away from the turbine wheel In response to a pressure-sensitive actuator. A pressure-operaled switch operates a warning light on the instrument panel in the event of excessive boost pressure developing. The turbo shaft is pressure-lubricated by an oil feed pipe from the main oil gallery The shaft floats on a cushion of oil. A drain pipo returns the oil to the sump.
Precautions The turbocharger operates at extremely high speeds and temperatures. Certain precautions must be observed, to avoid premature failure of the turbo, or injury to the operator. Do not operate the turbo with any of its parts exposed, or with any of ils hoses removed. Foreign objects falling onto the rotating vanes could cause excessive
damage, and (if ejected) personal injury. Do not race the engine immediately after start-up, especially if it Is cold. Give the oil a few seconds lo circulate. Always allow the engine to return to idle speed before switching il off - do not blip the throttle and switch off, as this will leave the turbo spinning without lubrication. Allow the engine to idle lor several minutes before switching off after a high-speed run. Observe the recommended intervals for oil and filter changing, and use a reputable oil of the specified quality. Neglect of oil changing, or use of Inferior oil, can cause carbon formation on the turbo shaft, leading to subsequent failure.
14 Turbocharger -removal and refitting
8 Disconnect the oil return pipe from the turbocharger (see Illustration). 9 Unscrew the bolt securing the mounting bracket to the cyfindar block. 10 Unscrew the mounting nuts and withdraw the turbocharger from the studs in Ihe exhaust manifold. Recover the gasket. II It Is to be refitted, store the turbocharger carefully, and plug its openings to prevent dirt ingress.
Refitting 11 Refitting Is a reversal of removal, bearing in mind the fallowing points: a) if a new turbocharger Is being fitted, change the engine oil and filter. b) Tighten ail nuts and bolts to the specified torque. c) Before starting the engine, prime the turbo lubrication circuit by disconnecting the stop solenoid iead at the injection pump, and cranking the engine on the starter for three ten-second bursts.
Removal 1 Remove the battery as described in Chapter 5A. 2 Unbolt and remove the relay guard and bracket from the left-hand side of Ihe engine. 3 Remove the air cleaner and ducting as descnbed in Section 2. 4 Loosen the clips and remove the air outlet duct between tho turbocharger and inlet manifold. Also disconnect the air inlet duct from the turbocharger. 6 Appty the handbrake, then jack up tho front of the vohicle and support on axle stands (see Jacking and vehicle support). 6 Bend back the locking tabs (if fitted) and unscrew the nuts securing the exhaust downpipe lo the exhaust manifold (see Illustration). Disconnect the downpipe from the exhaust system (refer to Part 4D) end remove it from under the vehicle. Recover tne gasket. 7 Unscrew ihe union nut and disconnect the oil supply pipe from the turbocharger. Recover the copper ring and tape over the end of the pipe 10 prevent dust entry.
15 Turbocharger -examination and renovation l
1 With the turbocharger removed, inspect the housing for cracks or other visible damage. 2 Spin the turbine or the compressor wheel, to verify that the shaft is intact and to feel for excessive shake or roughness. Some play is normal, since in use, the shaft is floating on a film of oil. Check that the wheel vanes are undamaged. 3 The wastegate and actuator are Integral, and cannot be checked or renewed separately. Consul! a Flat dealer or other specialist If it is thought that testing or renewal is necessary. 4 If tho exhaust or induction passages are ail* contaminated, Ihe turbo shaft oil seals have probably failed. 6 No DIY repair of the turbo is possible. A new unit may be available on an exchange basis,