check engine light FIAT PUNTO 1998 176 / 1.G Service Manual

2D*10 Engine removal and overhaul procedures
7.13 Positioning of piston rings (petrol engine) 11 Scrape away all traces of carbon from the top of the piston. A hand-held wire brush (or a piece of fine emery cloth) can be used, once the majority ot the deposits have been scraped away. 12 Remove the carbon from the ring grooves In the piston, using an old ring. Break the ring in half to do this (be careful not to cut your fingers - piston rings are sharp). Be careful to remove only the carbon deposits • do not remove any metal, end do not nick or scratch the sides of the ring grooves. 13 Once the deposits have been removed, clean the piston/connecting rod assembly with paraffin or o suitable solvent, and dry thoroughly. Make sure that the oil return holes In the ring grooves are clear. Fit the rings to their respective grooves meking sure they are positioned the correct way round where applicable (see illustration). 14 If the pistons and cylinder bores are not
7.22 Prising out the gudgeon pin retaining circilps damagea or worn excessively, and if the cylinder block does not need to be rebored. the original pistons can be refitted. Normal piston wear shows up as even vertical wear on the piston thrust surfaces, and slight looseness of the top ring In its groove. New piston rings should always be used when the engine is reassembled. 15 Carefully inspect each piston for cracks around the skirt, around the gudgeon pin holes, and at the piston nng lands (between the ring grooves). 16 Look for scoring and scuffing on the ptston skirt, holes in the piston crown, and burned areas at the edge of the crown. If the skirt is scored or scuffed, the engine may have been suffering from overheating, end/or abnormal combustion which caused excessively high operating temperatures. The cooling and lubrication systems should be checked thoroughly. Scorch marks on the sides of the pistons show that blow-by has occurred. A hole in the piston crown, or burned areas at the edge of the piston crown, Indicates that abnormal combustion has been occurring. If any of the above problems exist, the causes must be investigated and corrected, or the
7.26a Piston to connecting rod assembly (petrol engine) 1 Piston grade (A) end directional arrow on piston crown (towards timing belt end) 2 Connecting rod/cap matching numbers 3 Gudgeon pin offset in piston (0.9 to 1.1 mm) Arrow indicates direction of crankshaft rotation
7.26b Piston to connecting rod assembly (diesel engine) 1 Piston crown
damage will occur again. The causes may Include Incorrect Ignition/injection pump timing, or a faulty injector (as applicable). 17 Corrosion of the piston, in the form ol pitting, indicates that coolant has been leaking into the combustion chamber and/or the crankcase. Again, the cause must be corrected, or the problem may persist In the rebuilt engine. 16 Examine each connecting rod carefully for signs of damage, such as cracks around the big-end and small-end bearings. Check that the rod is not bent or distorted, Damage is highly unlikely, unless the engine has been seized or badly overheated. Detailed checking of the connecting rod assembly can only be earned out by an engine repair specialist with the necessary equipment. 19 Although not essential. It is highly recommended that the big-end cap bolts are renewed as a complete set prior lo refitting. 20 On petrol engines piston and/or con-necting rod renewal should be entrusted to an engine repair specialist, who will have the necessary tooling to remove and install the interference fit gudgeon pins. 21 On diesel engines, the gudgeon pins are of the floating type, secured in position by two circlips. On these engines, the pistons and connecting rods can be separated as follows. 22 Using a small fiat-bladed screwdriver, prise out ihe circlips, and push out the gudgeon pin (see illustration). Identify the piston and rod to ensure correct reassembly. Discard the circlips - new ones must be used on refitting. 23 Examine the gudgeon pin and connecting rod small-end bearing bush for signs of wear or damage. Bush renewal should be entrusted to an engine overhaul specialist. 24 The connecting rods themselves should not be In need of renewal, unless seizure or some other major mechanical failure has occurred. Check the alignment of the connecting rods visually, and if the rods are not straight, take ihem to an engine overhaul specialist for a more detailed check. 25 Examine all components, and obtain any new parts as necessary. If new pistons are purchased, they will be supplied complete with gudgeon pins and circlips. 26 On reassembly position the piston on the connecting rod as shown (see Illustrations),
Injection pump location Connecting rod/cap matching numbers 7.28c Piston crown on diesel engines

2D*10 Engine removal and overhaul procedures
9.1a Removing the oil return tube from the crankcase
pulling on the screw with a pair of grips, or by using a slide hammer. 2 Where applicable, undo Ihe retaining bolts and remove the piston oil Jet spray tubes from inside Ihe cylinder block. 3 Scrape all traces of gasket from the cylinder block/crankcase, taking care not to damage ihe gasket/sealing surfaces. 4 Remove all oil gallery plugs (where fitted). The plugs are usually very tight - they may have to be drilled out, and the holes re-tapped. Use new plugs when the engine is reassembled. 5 If the block is very dirty have it steam-cleaned, otherwise use paraffin to clean it. 6 Clean all oil holes and oil galleries again and dry thoroughly, then apply a light film of oil to all mating surfaces, to prevent rusting. Smear the cylinder bores with a light coating of oil. 7 All threaded holes must be clean, to ensure accurate torque readings during reassembly. To clean the threads, run the correct-size tap Into each of the holes to remove rust, corrosion, thread sealant or sludge, and to restore damaged threads (see illustration). If possible, use compressed air to clear the holes of debris produced by this operation. 8 Apply suitable sealant to the new oil gallery plugs, and insert them into the holes In the block. Tighten them securely, 9 Where applicable, refit the piston oil jet spray tubes to the cylinder block, and securely tighten the retaining bolts. Bend over the tabs to lock the bolts (see illustration). 10 Fit the new core plugs with sealant applied to their perimeters before using a suitable metal tube to drive them into position. 11 Refit the oil return tube to the crankcase and tighten the mounting bolts. 12 Refit the Injection pump/oil filter bracket together with a new gasket and lighten the bolts. 13 Refit the rear engine plate and tighten the bolts. Also refit 8ny other removed brackets etc.
Inspection 14 Visually check the cylinder block (or cracks and corrosion. Look for stripped threads in the threaded holes. If there has been any history of internal water leakage, it may bo worthwhile having on engine overhaul
9.1b Removing tho injection pump/oil filter bracket 9.1c Removing the injection pump/oil filter bracket gasket from the cyilndor block
9.1 d Removing the intermediate shaft bracket specialist check it with special equipment. 15 Check each cylinder bore for scuffing and scoring. Check for signs of a wear ridge at the top of the cylinder. Indicating that the bore Is excessively worn. 16 If the necessary measuring equipment is available, measure the bore diameters at the top Oust under the wear ridge), centre, and bottom, parallel to the crankshaft axis. 17 Next, measure the bore diameters at the same three locations, at right-angles to the crankshaft axis. If there is any doubt about the condition of the cylinder bores seek the advice of a Fiat dealer or suitable engine reconditioning specialist. 18 If the engine is not going to be reassembled right away, cover It with a large plastic bag to keep it clean and prevent rusting. If the engine is ready for reassembly, refit all the components and brackets removed.
9.1e Removing the oil vapour breather casing
10 Main and big-end bearings - ^ inspection and selection 5
Inspection 1 Even though the main and big-end bearings should be renewed during the engine overhaul, the old bearings should be retained for close examination, as they may reveal valuable information about the condition of the engine (see illustration overleaf). The bearing shells are available in different thicknesses to match the diameter of the Journal. 2 Bearing failure can occur due to lack of lubrication, the presence of dirt or other foreign particles, overloading the engine, or corrosion. Regardless of the cause of bearing

2D*10 Engine removal and overhaul procedures
12.18 Angle-tightening the main bearing cap bolts (petrol engine)
12.Ida Application area for silicone Instant gasket on crankshaft rear oil seal housing (petrol engine) 12.19b Refitting the crankshaft rear oil seal housing (petrol engine)
19 Fit a new oil seal to the crankshaft rear oil seal housing. Apply grease to the seal lips. On 1108 cc petrol engines a conventional gasket Is not used at the oil seal retainer joint face, but a 3 mm diameter bead of RTV (Instant) silicone gasket must be applied as shown -allow at least one hour 1or the gasket to cure before oil contacts it. On all other engines a gasket Is fitted Securely tighten the housing bolts (see Illustrations). 20 Check that Ihe crankshaft rotates freely by turning It by hand. If resistance Is fell, re-check the running clearances, as described above. 21 Carry out a check of the crankshaft endfloat as described at the beginning of Section 8. If the thrust surfaces of the crankshaft have been checked and new thrust washers hove been fitted, then the endfioat should be within specification.
22 Refit the pistons and connecting rods as described in Section 7. 23 Refit the flywheeVdriveplate, and-vibration plate (16-valvo engines), oil pump and pick-up tube, and sump with reference to the relevant Sections of Parts A, B or C of this Chapter.
13 Engine -initial start-up after overhaul and reassembly
1 With the engine refitted In the vehicle, double-check the engine oil and coolant levels. Make a final check that everything has been reconnected, and that there are no tools or rags left In the engine compartment.
Petrol engine models 2 Remove the spark plugs, then disable the
ignition system by disconnecting the LT wiring plug to the ignition colls. 3 Turn the engine on the starter until Ihe oi pressure warning light goes out. Refit ihe spark plugs, and reconnect the LT wiring.
Diesel engine models 4 Disconnect tho wiring from the stop solenoid on the Injection pump, then turn the engine on the starter motor until the oil pressure warning light goes out. Reconnect ihe wire to the stop solenoid. 6 Fully depress the accelerator pedal, turn tho ignition key to its first position and wait tor HHJ preheating warning light to go out.
All models 6 Start the engine, noting that this may take i little longer than usual, due to the fuel system components having been disturbed.
12.19c On diesel engines use a screwdriver to prise out the rear oil seal 12.19d Locate the new oil soalln the housing (diosel engine)... 12.19e ... and use a block of wood to drive it in
12.19f On Diesel engines fit the gasket to the cylinder block ... 12.19g ... then locate the rear oli seal housing... 12.19h ... and Insert the bolts

3*2 Cooling, heating and ventilation systems
12 If tho pump is stuck, tap It gently using a soft-faced mallet • do not lever between the pump and cylinder block mating faces.
Inspection 13 Check the pump body and impeller for signs of excessive corrosion. Turn the impeller, and check for stiffness due to corrosion, or roughness due to excessive end play. 14 Check the clearance between the pump Impeller and the casing using a feeler blade (see Illustration). If the clearance is different to that given In the Specifications, the pump must be renewed. No spare components are available; the pump can only be renewed as a complete assembly. 15 On diesel engine models, remove the O-rlng at the end ol the transfer pipe, which runs behind Ihe cylinder block and fits Into the rear of the coolant pump. A new O-rlng should be fitted as a matter of course.
Refitting
Petrol engine models 16 Commence refitting by thoroughly cleaning all traces of sealant from the mating faces of the pump and cylinder block/pump housing. 17 Apply a continuous bead of sealant {liquid gasket) to the cylinder block mating face of the pump, taking care not to apply excessive sealant, which may enter the pump itself (see Illustration). 18 Place the pump In position In Its housing, then refit and lighten the bolts/nuts to the specified torque. 19 Refit the liming belt as described In Chapter 2A or 28. 20 Refit the auxiliary drivebeltfs) and refill the cooling system as described in Chapter
t
A. 21 Reconnect Ihe battery negative terminal. Diesel engine models 22 Commence refitting by thoroughly cleaning all traces of old gasket from the mating faces of the pump housing and cylinder block. 23 Place a new gasket in position on (he cylinder block, locate the pump in position, then refit and tighten the bolts (see
7.17 On petrol engine models, apply a continuous bead of sealant (liquid gasket) to the pump mating face
pump Impeller and the casing using a feeler blode (diesel engine) illustration). Ensure that the end of the coolant transfer pipe seats firmly In tho port at the rear of the coolant pump, without displacing the O-ring seal. 24 Refit Ihe pump pulley, then refit the securing bolts and tighten to the specified torque. Counterhofd the pulley using the same method employed during removal. 25 Where applicable, refit the power steering pump with reference to Chapter 10. 26 Refit and tension the auxiliary drivebelt(s) as described in Chapter 18. 27 Refill (he cooling system as desenbed in Chapter 1B. 28 Reconnect the battery negative terminal.
8 Heater/ventilation components - § removal and refitting
Complete heater assembly

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Warning: On mode's fitted with air conditioning, do not attempt to remove the cooling unit, which Is located between the heater blower motor casing and the main heater assembly. Romovat of the cooling unit entails disconnection of refrigerant lines - refer to Section 10 for precautions to be observed.
rfJS
tf In any doubt as to the procedure fo follow on models with air conditioning, consult a Fiat dealer for advice. Note: This is an involved procedure, and It (s recommended fhat the following Section fs read thoroughly before commencing work. Plenty of time should be allowed to compter the operation. During dismantling, make notes on the routing of all wiring and cables, and the locations of all fixings, to aid reassembly. Removal 1 Disconnect the battery negative terminal (refer to Disconnecting the battery In the Reference Section of this manual), 2 Set the heater control to HOT. then drain the cooling system as described In Chapter 1A or 18. 3 Working in the engine bay, slacken the clips and dotach the healer unit coolant hoses from the ports at the bulkhead (see illustration) Recover the rubber grommets. 4 Refer to Chapter 11 and remove the entire facia assembly from the vehicle bulkhead. Rest the assembly on the front seats. 5 At this stage, access to the air l nlet/dlstrl but Ion/blending control cables is possible. These can be easily disconnected from their respective control levers and renewed If required. 6 Working from the engine bay. remove the protective plastic caps to expose the heater assembty mounting studs and remove the nuts 7 Label the electrical connections to 1hi» heater assembly, to aid correct refitting later and then unplug them at the connectors 8 Slacken and remove the nuts and lift the healer assembly off its mounting studs. Refitting 9 To refit the assembly, reverse the steps described for removal, bearing in mind the following points: a) Make sure that all wiring and cables are muted as noted during dismantling. b) Make sure that dl air ducts are securely reconnected. c) Refit the facia components with reference to Chapter 11. dl On completion, refill the cooling system as described In Chapter 1A or 18.
8.3 Slacken the clips (arrowed) and detach the heater unit coolant hoses from the ports at the bulkhead

4A*2 Fuel system -
single-point
petrol Injection models
1.1b IAW Weber-Marelli multi-point injection (MPI) system (16-valve engines) J Fuel
tank
2 Fuel pump 3 Multi-purpose
valve
4 Safety
valve
5 Anti-reflux
valve
6 F/fter 7 Battery 8
EVAP
solenoid
9 Dual
relay
10 Ignition switch 111nertia switch
12
Air conditioning compressor
13
Fuse 14 Throttle position sensor

1$
idle control stepper motor 17 Ignition coils 18 Sparkplugs 19 Fuel
rail
20 Pressure regulator 21 Injectors
15
Intake air temperature/pressure 22 Coolant temperature sensor sensor 23 Lambda/oxygen sensor
24 Rpm and TDC sensor 25 Engine immobiliser control unit 26 Catalytic converter 27 IAW failure warning light 28 EVAP canister 29 ECU 30 Diagnostic socket 31 Rev counter
Problems with the system should therefore be referred to a Fiat dealer for assessment. Once the fault has been Identified, the removal/ refitting procedures detailed in the following Sections can then be followed.
Precautions

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Warning: Many procedures In this Chapter require the removal of fuel lines and connections, which may result In fuel spillage. Before carrying out any operation on the fuel system, refer to the precautions given In Safety flrstl 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. Note that residual pressure will remain in the fuel lines long after the vehicle was last used, When disconnecting tny fuel line, first depressurise the fuel system {see Section 9).
2 Air cleaner and inlet system Sk - removal
and
refitting ^
Removal
1242 cc (8-valve) engines 1 Remove the air cleaner element as described In Chapter 1A. 2 Disconnect the outer section from the hot air tube and the Inlet air duct and remove it from the engine compartment. 3 If necessary remove the inlet air duct. 4 Disconnect the large and small breather hoses from the inner section of the air cleaner, then unscrew the retaining nuts and lift the section from the throttle body. 5 Recover the sealing ring. Check the nng for condition and renew it it necessary. 6 Wipe clean the inner surfaces of both the Inner and outer sections of the air cleaner,
1242 cc (16-valve) engines 7 Release the hose clip and disconnect the inlet air duct from the resonator (see illustration).
2.7 Release the hose clip and disconnect the inlet air duct from the resonator

Fuel system - diesel models 4C*3
8.5 Dial gauge (1), mounting bracket (2) and setting rod (3) In position on the injection pump (Lucas)
so that Its tip Is In contact with the bracket linkage (see Illustration). Position the dial gauge so that its plunger is at the mid-point of its travel and zero the gauge. 6 Rotate the crankshaft slowly in the correct direction of rotation (clockwise) until the crankshaft is positioned at TDC on No 1 piston with ell the sprocket timing marks aligned. 7 Check the reading on the dial gauge which should correspond to the value marked on the pump (there is a tolerance of * 0.04 mm). The timing value may be marked on a plastic disc attached to the front of the pump, or alternatively on a tag attached to Ihe pump control lever (see illustrations). 8 If adjustment is necessary, slacken the front pump mounting nuts/bolt and the raar mounting bolt, then slowly rotate tne pump body until the point is found where the specified reading is obtained on the dial gauge (access to the lower front bolt is gained through the hole in the injection pump sprocket). When the pump Is correctly positioned, tighten both its front mounting nuta/bolt and the rear bolt to their specified torque settings. 9 Withdraw the timing probe slightly, so that it
positioned clear of the pump rotor dowel. Rotato the crankshaft ihrough one and three quarter rotations in the normal direction of rotation. 10 Slide the timing probe back Into position ensuring that it Is correctly seated against the guide sealing washer surface, not (he upper Hp, then zero the dial gauge. 11 Rotate the crankshaft slowly in the correct direction ol rotation to the TDC position and recheck the timing measurement 12 If adjustment Is necessary, slacken the pump mounting nuts and bolt and repeat the operations in paragraphs 6 to 11. 13 When the pump timing is correctly set. remove the dial gauge and mounting bracket and withdraw the timing probe. 14 Refit the screw and sealing washer to the guide and tighten it securely.
8.7a Pump timing value (x) marked on plastic diso (Lucas)
15 If the procedure is being carried out as part of the pump refilling sequence, proceed as described in Section 5. 16 If the procedure is being carried out with the pump fitted to the engine, refit the injector pipes tightening their union nuts to the specified torque setting. Reconnect the battery and refit the air inlet ducting. 17 Start the engine, and check for any leakage at the fuel unions. To enable the engine to start it may be necessary to loosen tho injector union nuts while turning the engine on the starter motor in order to purge trapped air. 18 Check and If necessary adjust the Idle speed as described In Chapter 1B.
9 Fuel Injectors -testing, removal and refitting Sk ^

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Warning: Exercise extreme caution when working on the fuel injectors. Never expose the hands or any part of the body to Injector spray, as the high working pressure can cause the fuel to pen ot rate the skin, with possibly fatal results. You are strongly advised to have any work which involves testing the injectors under pressure carried out by a dealer or fuel Injection specie list.
Testing 1 Injectors do deteriorate with prolonged uso, and it is reasonable to expect them to need reconditioning or renewal after 60 000 miles
8.7b Pump timing values marked on label (1) and tag (2) (Lucas)
(100 000 km) or so. Accurate testing, overhaul and calibration of the Injectors must be left to a specialist. A defective injector which Is causing knocking or smoking can be located without dismantling as follows. 2 Run the engine at a fast idle. Slacken each Injector union In turn, placing rag around the union to catch spilt fuel, and being careful not to exposa the skin to any spray. When tho union on the defective Injector is slackened, the knocking or smoking will stop.
Removal 3 Remove ihe air Inlet ducting from tho front part of the onglne. 4 Carefully clean around the Injectors and injector pipe union nuts. 5 Pull the leak-off pipes from the injectors (see illustration). 6 Unscrow the union nuts securing Ihe injector pipes to the fuel Injection pump. Counterhold the unions on the pump when unscrewing the nuts. Cover open unions lo keep dirt out, using small plastic bags, or fingers cut from discarded (but clean!) rubber gloves. 7 Unscrew the union nuts and disconnect the pipes from the ln|ectors, If necessary, the Injector pipes may be completely removed-Note carefully the locations of the pipe clamps, for use when refitting. Cover tho onds ot (he injectors, to prevent dirt ingress. 8 Unscrew the injectors using a deep socket or box spanner, and remove Ihem from the cylinder head (see Illustration). 9 Recover the tire seal washers from the cy-linder head and discard them (see illustration).
9.5 Disconnecting the Injector leak-off pipes 9.8 Removing an injector

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,

4D*2 Exhaust and emission control systems
2.2 Charcoal canister location behind tho right-hand headlight
conditions, via a plunger valve, The system is controlled electronically by means of an emissions system control unit. Evaporative emission control • petrol models To minimise the escape of unburned hydrocarbons Into the atmosphere, an evaporallve loss emission control system is fitted to petrol models, The fuel tank filler cap Is sealed and a charcoal canister is mounted underneath the right-hand headlamp to collect the petrol vapours released from the fuel contained In the fuel tank. It stores them until they can be drawn from the canister (under the control of the fuel Injection/ignition system ECU) via the purge valve into the Inlet tract, where they are then burned by the engine during normal combustion. To ensure thai the engine runs correctly when it is cold and/or idling and to protect the catalytic converter from the effects of an over-rich mixture, the purge control valve is not opened by the ECU until the engine has warmed up, and the engine is under load; the valve solenoid is then modulated on and off to allow the stored vapour to pass into the inlet tract.
Exhaust systems The exhaust system comprises the exhaust manifold, an exhaust downpipe, • catalytic convorter, an intermediate pipe with silencer, and a tailpipe with silencer, On turbo diesel models the turbocharger is fitted between ihe exhaust manifold and the downpipe.
5.5a On 16-valve engines, undo the bolts and remove the manifold heat shield...
2 Evaporative loss emission ^ control system - information and component renewal ^
Information 1 The evaporative loss omission control system consists of the control solenoid (or purge valve), the activated charcoal filter canister and a series of connecting vacuum hoses. 2 The control solenoid and charcoal canister are both mounted on the right-hand side of the engine compartment behind the headlight (see illustration).
Component renewal
Control solenoid 3 With the bonnet open, disconnect the hoses from the control solenoid on the top of the charcoal canister. 4 Disconnect the wiring and remove the solenoid. 5 Refitting is a reversal of removal. Charcoal canister 6 Remove Ihe control solenoid as desenbed previously. 7 Disconnect Ihe fuel tonk hose from the canister 8 Detach the mounting and remove the canister. 9 Refitting Is a reversal of removal. Multifunction valve 10 The multifunction valve >s mounted on top of the luel tank. Removal and refitting is similar to that described for the tank sender gauge/pump (refer to Chapter 4A or 4B).
3 Crankcase emission system - general information
The crankcase emission control system consists of a hose from the camshaft cover to the air cloanor with a branch to Ihe throttle body. The main hose Incorporates a flame trap and the Inlet to the throttle body incorporates a calibrated hole.
5.5b ... then remove the bracket
The system requires no attention other than to check at regular intervals that tho hoses are free of blockages and undamaged.
4 Lambda oxygen sensor -removal and refitting &
Note: 7?5e Lambda oxygen sensor is doiicata and will not work if it is dropped or knocked, it its power supply is disrupted, or if any cleaning materials are used on it.
Removal 1 The sensor Is threaded Into the exhaust front downpipe. Access if best gained Irom underneath the vehicle. Apply the handbrake then )ack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). 2 Disconnect the sensor wiring connector located on the front of the engine. 3 Working beneath the vehicle, unscrew the sensor, taking care to avoid damaging the sensor probe as it Is removed- Note: As a flying lead remains connected to the sensor after it has been disconnected, if the correct spanner is not available, a slotted socket
will
be required to remove the sensor.
Refitting A Apply a little anti-selze grease to (he sensor threads • avoid contaminating the probe tip. 5 Refit the sensor to the downpipe. tightening it to the correct torque. Reconnect the wiring. 6 Lower the vohicle to the ground.
5 Exhaust manifold - % removal and refitting jk
Petrol models
Removal 1 On 1242 cc (16-valve) engines, remove tho air cleaner and inlet system components as described in Chapter 48. 2 Firmly apply the handbrake, then jock up the front of the car and support It securely on axle stands (see Jacking and vehicle support). 3 Disconnect the oxygen sensor wiring or alternatively romovo Ihe sensor completely. 4 Unscrew the nuts and disconnect the exhaust downpipo from Ihe exhaust manifold flange. Recover the gasket. 5 On 1242 cc (16-valve) engines, undo the bolts and remove the manifold heat shield, then remove the bracket at the timing belt end of the manifold (seo Illustrations). 6 Unscrew the mounting nuts, remove the washers, and recover any additional brackets fitted over the studs, noting their locations. Withdraw the manifold from the studs on the cylinder head. 7 Recover the gaskets from Ihe studs.

5A«2 Starting and charging systems
1 General information and precautions
General information The engine electrical system consists mainly of the charging and starting systems. Because of their engine-related functions, these components are covered separately from the body electrical devices such as the Ilght3, Instalments, etc (which are covered In Chapter 12). On petrol engine models refer to Part B for information on the ignition system, and on diesel models refer to Part C for information on the preheating system. The electncal system Is of 12-volt negative earth type. The battery fitted as original equipment is of maintenance* free (sealed for life} type and Is charged by the alternator, which is belt-driven from the crankshaft pulley. If a non-original battery is fitted It may be of standard or low maintenance type. The starter motor is of the pre-engaged type Incorporating an integral solenoid. On starting, the solenoid moves the drive pinion into engagement with the flywheel ring gear before the starter motor is energised. Once the engine has started, a one-way clutch prevents the motor armature being driven by the engine until the pinion disengages from the flywheel.
Precautions Further details of the various systems are given In the relevant Sections of this Chapter. While some repair procedures are given, the usual course of action is to renew the component concerned. The owner whose interest extends beyond mere component renewal should obtain a copy of the Automobile Electrical & Electronic Systems Manual, available from the publishers of this manual It Is necessary to take extra care when working on the electrical system to avoid damage to semiconductor devices (diodes and transistors), and to avoid the risk of personal injury. In addition to the precautions given in Safety first! at the beginning of this manual, observe the following when working on the system: Always remove rings, watches, etc before working on the electrical system. Even with the battery disconnected, capacitlve discharge could occur If a component's live terminal is earthed through a metal object. This could cause a shock or nasty bum. Do not reverse the battery connections. Components such as the alternator, electronic control units, or any other components having semi-conductor circuitry could be irreparably damaged. If the engine is being started using jump leads and a slave battery, connect the batteries positive-to-posibve and negative-to-
negative (see Jump starting). This also applies when connecting a battery charger but In this case both of the battery terminals should first be disconnected. Never disconnect the battery terminals, the alternator, any electrical wiring or any test Instalments when the engine Is running. Do not allow the engine to turn the alter-nator when the alternator Is not connected. Never test for alternator output by flashing the output lead to earth. Never use an ohmmeter ot the type Incorporating a hand-cranked generator for circuit or continuity testing. Always ensure that the battery negative lead is disconnected when working on the electrical system. Before using electric-arc welding equipment on the car, disconnect the battery, alternator and components such as the fuel Injection/ignition electronic control unit to protect them from the risk of damage. Several systems fitted to the vehicle require battery power to be available at all times, either to ensure their continued operation (such as the clock) or to maintain control unit memories or security codos which would be wiped if the battery were to be disconnected. To ensure that there are no unforeseen consequences of this action. Refer to Disconnecting the battery In the Reference Section of this manual for further Information.
2 Battery- % testing and charging
Standard and tow maintenance battery - testing 1 If the vehicle covers a small annual mileage, it is worthwhile checking the specific gravity of the electrolyte every three months to determine the state of charge of the battery. Use a hydrometer to make the check and compare the results with the following table, Note that the specific gravity readings assume an electrolyte temperature of 15*C (60'F); for every 10*C (18°f) below 158C (60aF) subtract 0.007, For every 108C (16'F) above 15"C (60'F) add 0.007. Ambient temperature Above 26"C Below 25DC Charged 1,210 to 1£30 1,270 to 1.290 70% charged 1.170to1.l90 1.230to1.250 Discharged 1.050toJ.070 1.110 to 1.130 2 If the battery condition is suspect, first check the specific gravity of electrolyte In each cell. A variation of 0.040 or more between any cells indicates loss of electrolyte or deterioration of the internal plates. 3 If the specific gravity variation is 0.040 or more, the battery should be renewed. If the cell variation Is satisfactory but the battery is discharged, it should be charged as described later in this Section.
Maintenance-free battery -testing 4 In cases where a sealed tor life maintenance-free battery is fitted, topplng-up and testing of the electrolyte in each cell Is not possible. The condition of the battery can therefore only be tested using a battery condition Indicator or a voltmeter. 5 Certain models may be fitted with a maintenance-free battery with a built-in charge condition Indicator. The indicator Is located in the top of the battery casing, and indicates the condition of the battery from its colour. If the Indicator shows green, then the battery is In a good state of charge. If the Indicator turns darker, eventually to black, then the battery requires charging, as described later in this Section. If Ihe indicator shows clear/yellow, then the electrolyte level in Ihe battery is too low to allow further use, and tho battery should be renewed. Do not attempt to charge, load or Jump start a battery when the indicator shows dear/yellow. 6 If testing the battery using a voltmeter, connect the voltmeter across the battery and compare the result with those given In the Specifications under 'charge condition'. The test is only accurate if the battery has not been subjected to any kind of charge for the previous six hours. If this is not the esse, switch on the headlights for 30 seconds, then wait four to five minutes baforo testing the battery after switching off the headlights. All other electrical circuits must be switched off, so check that the doors and tailgate are fully shut when making the test, 7 It the voltage reading Is less than 12.2 voHs, then the battery Is discharged, whilst a reading of 12.2 to 12.4 volts indicates 8 partially discharged condition. 6 If the battery Is to be charged, remove It from the vehicle (Section 3) and charge it as described later In this Section.
Standard and low maintenance battery - charging Note: The following is Intended as a guide only. Always refer to the manufacturer's recommendations (often printed on a label attached to the battery) before charging a battery. 9 Charge the battery at a rate of 3.5 to 4 amps and continue to charge the battery at this rate until no further rise In specific gravity Is noted over a four hour period. 10 Alternatively, a trickle charger charging at the rate of 1.5 amps can safely be used overnight. 11 Specially rapid boost charges which are claimed to restore the power of the battery in t to 2 hours are not recommended, as they can cause serious damage to the battery plates through overheating, 12 While charging the battery, note that the temperature of the electrolyte should never exceed 37.8*C(100°F),

5A«2 Starting and charging systems
Maintenance-free battery -charging Note: The following is intended as a guide only. Always refer to the manufacturer's recommendations (often printed on a label attached to the battery) before charging a battery. 13 This battery type takes considerably longer lo fully recharge than the standard type, the time taken being dependent on the extent of discharge, but it can take anything
up
to three days. 14 A constant voltage type charger is required, tooe set, when connected, to 13.9 to 14.9 votts wth a charger current below 25 amps. Using
mis
method, the battery should be usable within three hours, giving a voltage reading of 12.5 vofts. but this Is for a partially discharged battery and, as mentioned, full charging can
take
considerably longer. 15 If Ihe battery is to be charged from a fully discharged state {condition reading loss lhan 12.2 volts), have it recharged by your FIAT dealer or local automotive electrician, as Ihe charge rate is higher and constant super-vision during charging Is necessary.
3 Battery -removal and refitting
Note: Refer to Disconnecting the battery in ifte Reference Section of this manual before proceeding.
Removal 1 Slacken the clamp bolts and disconnect the ctamp from the battery negative (earth) terminal. 2 Remove the insulation cover (where fitted)
and
disconnect the positive terminal lead(s) in
Die same
way. 3 At the base of the battery, unscrew the bolt from the battery holding clamp plate and remove the clamp plate (see Illustration). A Remove the battery from Ihe engine compartment. 5 II necessary the mounting tray may be removed by unscrewing the bolts. On diesel models it will be necessary to remove the relay guard bolts as well.
Refitting 6 Refitting is a reversal of removal but make sure that the positive terminal is connected first followed by the negative terminal.
4 Alternator/charging system - >%•> testing in vehicle
Note: Refer to the warnings given in Safety first! and in Section 1 of this Chapter before starting work. 1 If the ignition warning light fails to Illuminate when the ignition is switched on, first check the alternator wiring connections for security. If satisfactory, check that the warning light bulb has not blown, and that the bulbholder is secure in its location in the instrument panel. If the light still fails to illuminate, check the continuity of the warning light feed wire from the alternator to the bulbholder. If all is satisfactory, the alternator is at fault and should be renewed or taken to an auto-electrician for testing and repair. 2 If the ignition warning light Illuminates when the engine Is running, stop the engine and check that the drivebelt is correctly tensioned (see Chapter 1A or 18) and that the alternator connections are secure. If all is so far satisfactory, have the alternator checked by an auto-electrician. 3 If the alternator output is suspect even though the warning light functions correctly, the regulated voltage may be checked as follows. 4 Connect a voltmeter across the battery terminals and start the engine. 5 Increase the engine speed until the voltmeter reading remains steady; the reading should be approximately 12 to 13 volts, and no more than 14 volts. 6 Switch on as many electrical accessories (eg. the headlights, heated rear window and heater blower) as possible, and check that the alternator maintains the regulated voltage at around 13 to 14 volts. 7 If ihe regulated voltage is not as stated, the fault may be due to worn brushes, weak brush springs, e faulty voltage regulator, a faulty diode, a severed phase winding or worn or damaged slip rings. The alternator should be renewed or taken to an auto-electrician for testing and repair.
3.3 Removing the battery clamp plate
5 Alternator -removal and refitting
Removal 1 Disconnect the battery negative terminal {refer to Disconnecting the battery In the Reference Section of this manual). 2 Firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands (see Jacking and vehicle support). Remove tho right-hand front roadwheel. 3 Remove Ihe Inner cover from under the right-hand wheelarch for access to tho right-hand side of the engine. 4 Disconnect the cables from the rear Of the alternator (see illustration).
Petrol models 5 Loosen the pivot and adjustment bolts then swivel the alternator towards the engine and slip off the drivebelt. Note that the position of the rpm sensor will prevent complete removal of the drivebelt from the crankshaft puiley. 6 Unscrew and remove the pivot and adjustment bolts then unscrew the upper slot-mounted bolt. Withdraw the alternator from the engine (see illustrations).
Diesel models 7 For additional working room, unclip and remove the upper timing belt cover then unbolt and remove the lower timing belt cover.
5.4 Cable connections on the rear of the alternator
5.6a Alternator adjustment and pivot bolts (petrol engine) B Adjuster bolt C Pivot bolt 5.6b Removing the alternator (petrol engine)