1997 FIAT PUNTO Idle speed

Maintenance schedule - diesel models 1B.3
The mamtenance intervals in this manual are provided with the assumption that you. reI ihe dealer, will be carrying out the work.
These
are the minimum maintenance intervals recommended by us for vehicles driven daily.
ff you wish to keep your vehicle In peak condition at all times, you may wish to perform some of these procedures more often. We encourage frequent maintenance, because it enhances the efficiency.
performance and resale value of your vehicle. When the vehicle Is new, it should be serviced by a factory-authorised dealer service department, in order to preserve the factory warranty.
Every 250 miles (400 km) or weekly O Refer to Weekly checks
Every 5000 miles (7500 km) or

6
months - whichever comes first • Renew the engine oil and filter (Section 3) P Drain any water from the fuel filter (Section 4)
Every 10 000 miles (15 000 km) or

12
months - whichever comes first ill addition lo tho Items listed above, cany out the following; D Check the operation of the brake warning lamp J (Section 5) Check the front brake pads for wear (Section 6) :-G Check the underbody and sealant for damage j" (Section 7) n Hose and fluid leak check (Section 8) 0 Check the condition of the exhaust system and its 1 mountings (Section 9) -D Check the condition of the driveshaft gaiters ", (Section 10) O Check and adjust the idle speed (Section 11) ;0 Renew (he fuel filter (Section 12) J] Renew the air filter element (Section 13) L) Renew the pollen filter (Section 14) •• Check the steering and suspension components • for condition and security (Section 15)
Every 20 000 miles (30 000 km) or

2
years - whichever comes first In addition to the Items listed above, cany out the following: (P Check and if necessary adjust the tension of the auxiliary drlvebeltfs) (Section 16) '• Check the freeplay and height of the clutch pedal " (Section 17) D Check and if necessary adjust the valve clearances (Section 18) Lubricate all hinges and locks (Section 19) • Check the headlight beam adjustment (Section 20) O Cany out a road test (Section 21)
Every 30 000 miles (45 000 km) or
3 years - whichever comes first In addition to the Items listed above, cany out the following: • Check and if necessary top-up the manual transmission oil level (Section 22)
Every 40 000 miles (60 000 km) or
4 years - whichever comes first In addition to the items listed above, cany out the following: • Check the rear brake shoes for wear (Section 23) • Renew the timing belt (Section 24)'
•Note: Although the normal interval for timing belt renewal is 70 000 miles (ids 000 km), it is strongly recommended that the belt Is renewed at 40 000 miles (60 000 km) on vehicles which are subjected to intensive use, le. mainly short Journeys or a lot of stop-start driving. The actual bait renewal interval Is therefore very much up to the Individual owner, but bear in mind that sevefe engine damage will result if the belt breaks.
Every 60 000 miles (90 000 km) or
6 years - whichever comes first In addition to the Items listed above, cany out the following: • Check the condition and operation of the emission control system components (Section 25)
Every 80 000 miles (120 000 km) • Renew the manual transmission oil (Section 26)
Every 2 years
(regardless of mileage) • Renew the engine coolant (Section 27) • Renew the brake fluid (Section 28)

Component location - diesel models ib-s
Rear underbody view - turbo diesel model
1
Fuel tank
2
Exhaust
tailpipe
and
silencer 3 Fear axle 4 Coil springs 5
Rear anti-roll bar
€
Handbrake cables
7
Rear brake pressure regulating valve
8
Rear shock
absorber
lower
mountings
Maintenance procedures
1 Introduction
This Chapter Is designed to help the home mechanic maintain his/her vehicle for safety, economy, long life and peak performance. The Chapter contains a master maintenance schedule, and Sections dealing specifically with each task in the schedule. Visual checks, adjustments, component renewal and other helpful items are included. Refer to the accompanying illustrations of the engine compartment and the underside of the vohicle for the locations of the various components. Servicing your vehicle in accordance with ihe mileage/time maintenance schedule and the following Sections will provide a planned maintenance programme, which should result in a long and reliable service life. This is a comprehensive plan, so maintaining some items but not others at the specified service internals, will not produce the same results. As you service your vehicle, you will ctecover that many of the procedures can. and should, be grouped together, because of the particular procedure being performed, or because of the proximity of two otherwise-unrelated components to one another. For example, if the vehicle is raised for any reason, the exhaust can be inspected at the same time as the suspension and steering components. The first step in this maintenance programme is to prepare yoursetf before the
actual work begins. Read through all the Sections relevant to the work to be carried out. then make a list and gather all the parts and tools required. If a problem is encountered, seek advice from a parts specialist, or a dealer service department.
2 Regular maintenance
1 If, from the time Ihe vehicle is new, the routine maintenance schedule is followed closely, and frequent checks are made of fluid levels and high-wear Items, as suggested throughout this manual, the engine wifl be kept in relatively good running condition, and the need for additional work will be minimised. 2 It is possible that there will be times when the engine is running poorly due to the lack of regular maintenance. This is even more likely if a used vehicle, which has not received regular and frequent maintenance checks, is purchased, in such cases, additions! work may need to be carried out, outside of the regular maintenance intervals. 3 If engine wear is suspected, a compression test {refer to Chapter 2C} will provide valuable information regarding the overall performance of the main internal components. Such a test can be used as a basis to decide on the extent of the work to be carried out. If, for example, a compression test indicates serious Internal engine wear, conventional maintenance as
described in this Chapter will not greatly improve the performance of the engine, and may prove a wa3te of time and money, unless extensive overhaul work Is carried out first. 4 The following series of operations are those usually required to Improve the performance of a generally poor-running engine:
Primary operations a,I Clean, Inspect and test the battery (See Weekly checks). b) Check all the engine-related fluids (See Weekly checks). c) Drain the water from the fuel filter (Section 4) d) Check the condition and tension of the auxiliary dnvebeft(s) (Section 16). e) Check the condition of the air fitter, and renew if necessary (Section 13). f) Check the condition of all hoses, and check for fluid leaks (Section 8). g) Check the engine idle speed setting {Section 11). h) Check the exhaust gas emissions (Section 25). 5 If the above operations do not prove fully effective, carry out the following secondary operations:
Secondary operations All items listed under Pnmary operations, plus the following: a) Check the charging system (Chapter 5A, Section 4). b) Renew the fuel filter (Section 12) and check the fuel system (see Chapter 4Q.

ib-8 Every 10 000 miles - diesel models
10.1 Checking the condition of a driveshaft gaiter
9 Exhaust system check
1 With the engine cold {at least an hour after tho vehicle has been driven), check ihe complete exhaust system from the engine to the end of the tailpipe. The exhaust system Is most easily checked with the vehicle raised on a hoist, or suitably supported on axle stands (see Jacking and vehicle support), so that the exhaust components are readily visible and accessible. 2 Check the exhaust pipes and connections for evidence of leaks, severe oorrosion and damage. Make sure that all brackets and mountings are In good condition, and that all relevant nuts and bolts are tight, Leakage at any of the joints or in other parts of tho system will usually show up as a black sooty stain in the vicinity ot the leak. 3 Rattles and other noises can often be Iracod to the exhaust system, especially the brackets and mountings. Try to move the pipes and silencers. If the components are able to come into contact with the body or
suspension parts, secure the system with new mountings. Otherwise separate the joints (if possible) and twist the pipes as necessary to provide additional clearance.
10 Driveshaft gaiter check
I
1 With the vehicle raised and securely supported on stands (see Jacking and vehicle support), turn the steering onto lull lock, then slowly rotate the roadwheel. Inspect the condition ol the outer constant velocity (CV) joint rubber gaiters, squeezing the gaiters to open out the folds. Check for signs ot cracking, splits or detenoration of the rubber, which may allow the grease to escape, and lead to water and grit entry into the joint. Also check the security and condition of the retaining clips. Repeat these checks on the Inner CV joints (see illustration). If any damage or deterioration is found, the gaiters should be renewed (see Chapter 8. Section 3). 2 At the same time, check the general condition of the CV joints themselves by first holding the driveshaft and attempting to rotate the wheel. Repeat this check by holding the inner joint and attempting to rotate the driveshaft. Any appreciable movement indicates wear in the joints, wear in Ihe driveshaft splines, or a loose driveshaft retaining nut.
11 Idle speed check and adjustment
1 The usual type of tachometer (rev counter), which works from ignition system pulses, cannot be used on diesel engines. A
diagnostic socket is provided for the use of Flat test equipment, but this will not normally be available to the home mechanic. If it Is not felt that adjusting the Idle speed by ear 19 satisfactory, It will be necessary to purchase or hire an appropriate tachometer, or else leave tho task to a Fiat dealer or other suitably equipped specialist, 2 Before making adjustments, warm up the engine to normal operating temperature. Make sure that the accelerator cable is correctly adjusted (see Chapter 4C). 3 The adjustment must be made with all electrical components (Including the cooling fan) switched off. It the fan comes on dunng the adjustment, wait until it switches off automatically before proceeding. 4 The idle adjustment screw Is located on the top of the fuel injection pump (see illustration). To adjust the idie speed loosen the locknut and turn the screw as required then tighten the locknut. 5 On completion switch off the engine.
12 Fuel filter renewal i
1 The fuel filter is located on the bulkhead in the engine compartment. An electrically-operated heater is located between the filter and tlw housing, 2 Position a suitable container under the fuel filler. Loosen tho bleed screw on the top of the filter, then disconnect the wiring from Ihe water sensor and loosen the water drain screw on the bottom of the filter. Allow the fuel to drain completely (see illustration). 3 Tighten the drain and bleed screws, then Use an oii niter strep to loosen the fuel filter {see illustration).
12.2 Loosening the bleed screw on the top of the fuel filter
11.4 fdie speed adjustment 1 Locknut 2 Adjustment screw

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
2.11 Unscrewing the crankshaft pulley bolts
6 Itae crankshaft sprocket Is also equipped •nth a timing mark - when this is aligned with 3relarence marking on the oil pump cover.
Hie
engine is set with cylinders No 1 and 4 at
TDC.
Note that it is the camshaft positioning that determines whether a cylinder is on its comcression or exhaust stroke.

Location
of TDC on cylinder No 1 7 Remove the air cleaner and ducting as descnbed in Chapter 4A or 4B. Remove the
spark
plug from No 1 cylinder as described in Chapter 1A. 8 Firmly apply the handbrake, then |ack up
the
front of the car and support it securely on iiia stands (see Jacking end vehicle support). 9 Remove the auxiliary drivebelt(s) as described in Chapter 1A. 10 Unbolt and remove the timing belt cover. Mole the bolt located at the bottom of the
coven
this can be easily overlooked. 11 Undo the three bolts and remove the crankshaft pulley from the sprocket (see {lustration). 12 Turn Ihe engine in its normal direction of rotation (using a socket or spanner on Ihe crankshaft sprocket centre bolt) until pressure an be felt at No
1
cylinder spark plug hole.
1 flfliyflg^ Remove all four spark plugs; "••"•1 this will make the engine HlNTl easier to turn; refer to Chapter 1A for details.
13 Continue turning the engine until the crahaft sprocket TDC timing mark is aligned with the mark on the cylinder head and the crankshaft sprocket timing mark is aligned with the mark on the oil pump cover (see ilustrations). 14 The engine is now set at TDC for No 1 cylinder on compression.
3 Cylinder compression test t ^
1 When engine performance Is down, or if misfiring occurs which cannot be attributed to tne ignition or fuei systems, a compression isst can provide diagnostic clues as to the
2.13a Camshaft sprocket and cylinder head TDC timing marks (arrowed) aligned -shown with timing belt removed engine's condition. II the test is performed regularly, it can give warning of trouble any other symptoms become apparent. 2 The engine must be fully warmed-up to normal operating temperature, the battery must be fufly charged, and all the spark plugs must be removed (Chapter 1A). The aid of an assistant will also be required. 3 Disable the ignition system by dis-connecting the LT wiring plug to the ignition coils. 4 Fit a compression tester to the No 1 cyl-inder spark plug hole - the type of tester which screws into the plug thread is to be preferred, 5 Have the assistant hold the throttle wide open, and crank the engine on the starter motor; after one or two revolutions, the compression pressure should build up to a maximum figure, and then stabilise. Record the highest reading obtained. 6 Repeat the lest on the remaining cylinders, recording the pressure in each. 7 All cylinders should produce very similar pressures; any excessive difference indicates the existence of a fault. Note that the compression should build up quickly in a healthy engine; low compression on the first stroke, followed by gradually increasing pressure on successive strokes, indicates worn piston rings. A low compression reading on the first stroke, which does not build up during successive strokes, indicates leaking valves or a blown head gasket (a cracked head could also be the cause). 8 If the pressure in any cylinder is very low. carry out the following test to isolate the cause. Introduce a teaspoonful of clean oil into that cylinder through its spark plug hole and repeat the test. 9 If the addition of oil temporarily improves the compression pressure, this indicates that bore or piston wear Is responsible for the pressure loss. No improvement suggests that leaking or burnt valves, or a biown head gasket, may be to blame. 10 A low reading from two adjacent cylinders is almost certainly due to the head gasket having blown between them; the presence of coolant in the engine oil will confirm this. 11 If one cylinder is about 20 percent lower
2.13b Crankshaft sprocket and oil pump cover TDC timing marks (arrowed) aligned
than the others and Ihe engine has a slightly rough idle, a worn camshaft lobe could be the cause. 12 On completion of the test, refit the spark plugs and reconnect the ignition LT wiring plug.
4 Timing belt and covers -removal and refitting ^
Note: Fiat specify the use of a special timing belt fens/on measuring toot to correctly set tho timing belt tension. If access to this equipment cannot be obtained, an approximate setting can be achieved using the method described below. It the method described is used, the tension must be checked using the special tool at the earliest possible opportunity. Do not drive the vehicle over large distances, or use high engine speeds, until the belt tension is known fo be correct. Refer to a Fiat dealer foradvSce.
General information 1 The function of the timing belt is to drive Ihe camshaft and coolant pump. Should the belt slip or break In service, the valve timing will be disturbed and piston-to-valvo contact will occur, resulting in serious engine damage, 2 The timing belt should be renewed ai the specified intervals (see Chapter 1A), or earlier if it is contaminated with oil. or if it is at all noisy in operation (a scraping noise due to uneven wear). 3 If the timing belt is being removed, it Is a wise precaution to check the condition of the coolant pump at the same time (check for signs of coolant leakage). This may avoid the need to remove the timing belt again at a later stage, should the coolant pump fall.
Removal 4 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 the right-hand front road wheel. 5 Remove the air cleaner and air ducting as described in Chapter 4A or 46. 6 Remove the auxiliary drivebelt(s) and the spark plugs as described in Chapter 1A.
2A

2C*2 Diesel engine in-car repair procedures
4.4a Unbolt the engine oil dipstick tube...
3 Cylinder compression test
Note: A compression tester specifically designed for diesef engines must be used for this test. 1 When engine performance Is down, or if misfiring occurs, a compression test can provide diagnostic clues as to the engine's condition, If the lest is performed regularly, it can give warning of trouble before any other symptoms become apparent. 2 A compression tester specifically Intended for diesel engines must be used, because of the higher pressures involved. The Ie6ter is connected to an adapler which screws Into the glow plug or injector hole. It is unlikely to be worthwhile buying such a tester for occasional use. but it may be possible to borrow or hire one • if not. have the test performed by a garage. 3 Unless specific instructions to the contrary are supplied with the tester, observe the following points: 9) The battery must bo in a good state of charge, the air titter must be clean, end the engine should be at normal operating temperature. b) AH the in/actors or glow plugs should be removed before starting the lest. If removing the injectors, also remove the flame shield washers, otherwise they may be blown out. c) The stop solenoid must be disconnected.
4.4b ... and remove it from the rubber grommet in the oil pump housing
fo prevent the engine from running or fuel from being discharged. 4 There is no need to hold the accelerator pedal down during the test, because the diesel engine air inlet is not throttled. 5 The cause of poor compression Is less easy to establish on a diesel engine than on a petrol one. The effect of introducing oil into the cylinders (wet testing) Is not conclusive, because there is a risk that the oil will sit in the recess on the piston crown, instead of passing to the rings. However the following can be used as a rough guide to diagnosis. 6 All cylinders should produce very similar pressures; a difference of more than 5 bars between any two cylinders Indicates the existence of a fault. Note that the compression should build up quickly In a healthy engine; low compression on the first stroke, followed by gradually-increasing pressure on successive strokes, indicates worn piston rings. A low compression reading on the first stroke, which does not build up during successive strokes, indicates leaking valves or a blown head gasket (a cracked hoad could also be the cause). 7 A low reading from two adjacent cylinders Is almost certainly due to the head gasket having blown between them: the presence of coolant In the engine oil will confirm this,
Leakdown test 8 A leakdown test measures the rate at which compressed air fed into the cylinder Is lost. It is an alternative to a compression test, and in many ways it is better, since the escaping air provides easy identification of where pressure loss is occurring (piston rings, valves or head gasket). 9 The equipment needed for leakdown testing is unlikely to be available to the home mechanic. If poor compression Is suspected, have the test performed by a suitably-equipped garage.
4 Timing belt and covers -removal
and
refitting
Note: Fiat specify the use of a spec/a/ timing belt tension measuring tool to correctly set the timing belt tension. If access to this equipment cannot be obtained, an approximate setting can be achieved using the method described below. If the method described is used, the tension must be checked using the special tool at the earliest possible opportunity. Do not drive the vehicle over large distances, or use high engine speeds, until the belt fens/on rs known to be correct. Refer to a Fiat dealer for advice.
General Information 1 The function of the timing belt is to drive the camshaft and fuel injection pump. Should the belt slip or break in service, the valve timing will be disturbed and piston-to-valve contact
will occur, resulting In serious engine damage. 2 The timing bolt should be renewed at the specified intervals (see Chapter 1B), or earlier If It is contaminated with oil. or If It is at al noisy In operation (a scraping noise due to uneven wear),
Removal 3 Set the engine at TDC on No 1 cylinder
as
described in Section 2. 4 Unbolt and remove tho engine oil dipstick tube and remove It from the rubber gromme! in the oil pump housing (see illustrations), 5 Before removing the timing belt check rts tension by turning the belt through 90" with finger and thumb midway between u* injection pump and camshaft sprockets. This will give you an Idea of the tension to apply when refitting, assuming the tension is already correct. Also note the position of the tensions pulley as a reference mark. 6 Release tho nut on the timing bea tensioner, move the tensioner pulley away from the belt and retlghten the nut to hold the pulley in the retracted position. 7 If the timing belt is to be re-used, use white paint or chalk to mark the direction of rotation on the belt (if markings do not already exist), then slip the belt off the camshaft, crankshaft and injection pump sprockets, and the idler and tensioner pulleys. Caution: If the belt appears to be In good condition and can be re-used, it fs essential that It Is refitted the same
wsy
round, otherwise accelerated wear will result, leading fo premature failure. 8 Check the timing belt carefully for any signs of uneven wear, splitting, or oil contamination. Pay particular attention to the roots of the teeth. Renew it if there is the slightest doutt about its condition. If the engine is undergoing an overhaul, renew the belt as a matter of course, regardless of its apparent conditio*. The cost of a new belt Is nothing compa/ed with the cost of repairs, should the belt freak in service. If signs of oil contamination art found, trace the source of the oil leak and rectify It. Wash down the engine timing baft area and all related components, to remove
sd
traces of oil.
Refitting 9 Before refitting, thoroughly clean the tknmg belt sprockets. Check that the tensioner and idler pulleys rotate freely, without any sign ol roughness. If necessary, renew them as described in Section 5. 10 Ensure that the crankshaft, camshaft and injection pump sprockets are still at their TDC positions as described In Section 2. 11 Engage the timing belt with the crankshaft sprocket, then locate it around the idler pufiey and onto the Injection pump sprocket making sure that it is kept taught. Continue to locate! around the camshaft sprocket and finally around Ihe tensioner pulley (see Illustration) Ensure the belt teeth seat correctly on Ihe sprockets.

4A«1
Chapter 4 Part A:
Fuel system - single-point petrol injection models
Contents
Accelerator cable • removal, refitting and adjustment 4 Air cleaner and inlet system - removal and refitting 2 Air cleaner filter element renewal See Chapter 1A Engine management system components - removal 8nd refitting .. 5 fuel filter renewal See Chapter 1A Fuel injection system - depressurlsatlon 8 Fuel injection system • testing and adjusting 10
Degrees of difficulty
Fuel pump/fuel gauge sender unit - removal and refitting 8 Fuel tank - removal and refitting 7 General information and precautions 1 Idle speed and mixture adjustment See Chapter 1A Inlet air temperature regulator • removal and refitting 3 Inlet manifold - removal and refitting 9 Unleaded petrol - general Information and usage 11
Easy, suitable for Fairty easy, suitable Fairly difficult, Jx suitable for competent ^ OY mechanic ^
DifficUt, suitable tor % Very difficult, ^ novice with Me for begrmer with &
Fairly difficult, Jx suitable for competent ^ OY mechanic ^ experienced DIY > * suitable for expert D(Y JS or professional ^ experience some experience &
Fairly difficult, Jx suitable for competent ^ OY mechanic ^ mechanic > * suitable for expert D(Y JS or professional ^
Specifications
System type Weber-Marelll integrated single-point fuel injection/ignition system
Fuel system data Fuel pump type Electric, Immersed in fuel tank Fuel pump delivery rate 110 litres/hour minimum Regulated fuel pressure 1.0 ± 0.2 bar Crankshaft TDC sensor resistance at 20°C €50 to 720 ohms Injector duration (at idle)
1
£ ms
Recommended fuel Minimum octane rating 95 RON unleaded
Torque wrench settings Nm ibfft Coolant temperature sensor 3 2 Fuel filter collar nut S 4 Fuel tank 28 21 Idle control stepper motor 4 3 Inlet manifold 27 20 Inlet union to filter 31 23 Outlet union to filter 15 11 Throttle body to manifold 7 5 Throttle potentiometer 3 2

4A*2 Fuel system - single-point petrol Injection models
1 General information and precautions
General information The iAW Weber-Marelli single point Injection (SPI) system is a self-contained engine management system, which controls both the fuel Injection and Ignition (see Illustration), This Chapter deals with the fuel Injection system components only - refer to Chapter 5B for details ol the ignition system components. The fuel Injection system comprises a fuel tank, an electric fuel pump, a fuel filter, fuel supply and return lines, a throttle body with an integral electronic fuel Injector, and an Electronic Control Unit (ECU) together with its associated sensors, actuators and wiring. The fuel pump delivers a constant supply of fuel through a cartridge fitter to the throttle body, and the fuel pressure regulator (integral with the throttle body) maintains a constant fuel pressure at the fuel injector and returns excess fuel to the tank via the return line. This
constant flow system also helps to reduce fuel temperature and prevents vaporisation. Tne fuel injeclor Is opened and closed by an Electronic Control Unit (ECU), which calculates the injection timing and duration according to engine speed, throttle position and rate of opening, Inlet air temperature, coolant temperature and exhaust gas oxygen content information, received from sensors mounted on the engine. inlet air is drawn Into the engine through the air cleaner, which contains a renewable paper filter element. The inlet air temperature is regulated by a vacuum operated valve mounted in the air ducting, which blends air at ambient temperature with hot air, drawn from over the exhaust manifold. Idle speed is controlled by a stepper motor located on the side of the throttle body. Cold starling enrichment is controlled by the ECU using the coolant temperature and inlet air temperature parameters to increase the injector opening duration. The exhaust gas oxygen content is constantly monitored by the ECU via the Lambda (oxygen) sensor, which is mounted in
me exhaust downpipe. The ECU then uses this Information to modify the Injection timing and duration to maintain the optimum air/fuel ratio. An exhaust catalyst Is fitted to all SPI models. The ECU also controls the operation of the activated charcoal filter evaporative loss system • refer to Chapter 4D for further details. It should be noted that fault diagnosis of the I IAW Weber-Marelli system is only possible with dedicated electronic test equipment. Problems with the system should therefore be I referred to a Flat dealer for assessment. Once i the fault has been Identified, the I removal/refitting procedures detailed in the following Sections can then be followed.
Precautions |

A


Warning: Many procedures in thH Chapter require the removal ot fuel lines and connections, which may result in fuel spillage. Before carrying | out any operation on Me fuel system, refer to the precautions given In Safety flrstt at the beginning ot this manual, and follow them Implicitly. Petrol Is a highly dangerous and volatile liquid, and the precautions
1.1 IAW Weber-Marelli single point Injection (SPI) system 1 Fuel
tank
2 Fuel pump 3 Fuel filter 4 Anii'reflux valve 5 Fuel pressure regulator 6 Injector
7 Air cleaner 8 Fuel vapour
trap
9 Idle stepper motor
10
Absolute pressure sensor J11njection/ignition ECU 12 Tnrottle position sensor
13 Engine coolant temperature sensor 14 Intake air temperature sensor 15 Inject'onfignitron dual
relay
16 Ignition coils 17 Rpm and TDC sensor
18 Spark plugs 79 Diagnostic socket 20 EVAP solenoid 21 Lambda/oxygen sensor 22 Rev counter 23 IAW failure warning light

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.