1997 FIAT PUNTO Wiring

ia«8 Every 10 000 miles - petrol models
5.2 Check the thickness of the pad friction material through the hole on the front of the caliper should be removed and cleaned. The operation of the caliper can then
bIbo
be checked, and the condition of the brake disc itself can be fully examined on both sides. Refer to Chapter 9 for further Information. 4 If any pad's friction material is worn to the specified thickness or less, all four psds must tie renewed as a set. Refer to Chapter 9. 5 On completion refit the roadwheels and lower the car to the ground
6 Underbody sealant check
I
1 Jack up the front and rear of the car and support It securely on axle stands (see Jacking and vehicle support). Alternatively position the car over an inspection pit. 2 Check the underbody. wheel housings and side sills for rust and/or damage to the under-body sealant. If evident, repair as necessary.
7 Hose and fluid leak check ^
I
1 Visually Inspect the engine joint laces, gaskets and seals for any signs of water or oil leaks. Pay particular attention to the areas around the camshaft cover, cylinder head, oil (liter and sump joint faces. Bear in mind that.
A leak In the cooling system will usually show up as white or rust~coloured deposits on the area adjoining the leak
over a period of time, some very slight seepage from these areas is to be expected -what you are really looking for is any indication of a serious leak (see Haynes Hint). Should a leak be found, renew the offending gasket or oil seal by refemng to the appropriate Chapters in this manual. 2 Also check the security and condition of all the engine-related pipes and hoses. Ensure that all cable-ties or securing clips ore In place and In good condition, Clips which are broken or missing can lead to chafing of the hoses, pipes or wiring, which could cause more serious probioms In the luture. 3 Carefully check the radiator hoses and heater hoses along their entire length. Renew any hose which is cracked, swollen or deteriorated, Cracks will show up better if the hose is squeezed. Pay close attention to the hose clips that secure the hoses to the cooling system components. Hose clips can pinch and puncture hoses, resulting in cooling system leaks. 4 Inspect all 'he cooling system components {hoses. |olnt faces etc.) for leaks. A leak in the coolmg system will usually show up as white-or rust-coloured deposits on the area adjoining the leak. Where any problems of this nature are found on system components, renew the component or gaskel with reference to Chapter 3. 5 Where applicable, inspect the automatic transmission fluid cooler hoses for leaks or deterioration. 6 With the vehicle raised, inspect the fuel tank and filler neck for punctures, cracks and other damage. The connection between the filler neck and tank Is especially critical. Sometimes a rubber filler neck or connecting hose will leak due to loose retaining clamps or deten orated rubber. 7 Carefully check all rubber hoses and metal fuel lines leading away Irom the fuel tank. Check for loose connections, deteriorated hoses, crimped lines, and other damage. Pay particular attention to the vent pipes and hoses, which often loop up around the fitter neck and can become blocked or crimped. Follow the lines to the front of the vehicle, carefully inspecting them all the way. Renew damaged sections as necessary. 8 From within tne engine compartment,
check the security of all fuel hose attachments and pipe unions, and inspect the fuel hoses and vacuum hoses for kinks, chafing and deterioration. 9 Where applicable, check the condition of the power steering fluid hoses and pipes.
8 Exhaust system check fe
1 With the engine cold (at least an hour after the vehicle has been driven), check the 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 corrosion and damage. Make sure thai 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 the system will usually show up as a black sooty stain in the vicinity of the leak. 3 Rattles and other noises can often bo traced 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.
9 Driveshaft gaiter check
9.1 Checking the condition of a driveshaft gaiter
1
1 With the vehicle raised and securely supported on stands (see Jacking and vehicle support), turn the steering onto full lock, then s'owly rotate the roadwheel. Inspect the condition of Ihe outer constant velocity (CV) joint rubber garters, squeezing the gaiters to open out the folds. Check for signs of cracking, splits or deterioration 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 (he CV joints themselves by first holding (he 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 the driveshaft splines, or a loose driveshaft retaining nut

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

A


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.

ia.14 Every 20 000 miles - petrol models
16 Test the operation of the brake servo unit as follows. With the engine off, depress the footbrake four or five times to exhaust the vacuum. Hold the brake pedal depressed, then start the engine. As the engine starts.
there should be a noticeable give In the brake pedal as vacuum builds up. Allow the engine to run for at least tsvo minutes, and then switch it off. If the brake pedal is depressed now. it should be possible to detect a hiss
from the servo as the pedal is depressed. After about four or five applications, no further hissing should be heard, and the pedal shouto feel considerably harder.
Every 30 000 miles (45 000 km) or 3 years
. transmission (see illustration). Using an Allen 25 Lambda/oxygen sensor ^ key, unscrew the plug and clean it. check \ 3 The oil level should reach the lower edge of ^ the filler/level hole. A certain amount of oil will have gathered behind the filler/level plug, and If the CO level at the exhaust tailpipe is too w,u tr,cWe out when is 'e™oved; this does high or low, Ihe vehicle should be taken to a «©l necessarily Indicate that the level is Fiat dealer so lhat the complete fuel-injection correct. To ensure that a true level is and ignition systems, including the Lamoda/ established, wait until the Initial trickle has oxygen sensor, can be thoroughly checked stopped, then ado oil as necessary until a using the special diagnostic equipment. Once ,r,ckle o1 new oil can be seen emerging. The these have been checked and are known to 'W wl" be correct when ,he flow ceases-us® be free from faults, the fault must be in the good-quality oil of the specified type, catalytic converter, which must be renewed Make sur®that vehicle Is completely level as described In Chapter 4D, Section 6. checking the level and do not overfill, 4 When the level Is correct refit and tighten the plug and wipe away any spilt oil.
26 Manual transmission oil level check ^ 27 Evaporative loss system ^ check
1 Park Ihe vehicle on a level surface, If possible over an inspection pit or on a ramp as the filler/level plug is best reached from under Ihe engine compartment. The oil level must be checked before the car is driven, or at least 5 minutes after the engine has been switched off. If the oil ts checked Immediately alter driving the car, some of the oil will remain distributed around the transmission components, resulting in an inaccurate level reading. 2 Wipe clean the area around the filler/level plug, which is situated on the front of the
Refer to Chapter 40 Section 2 and check that all wiring and hoses are correctly connected to the evaporative toss system components.
28 Automatic transmission fitter and fluid change
1 Take the vehicle on a short run. to warm the transmission up to operating temperature.
Park the car on level ground, then switch off the Ignition. 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]. Note thai, when refilling and checking Uie fluid level, the car must be lowered to the ground, and level, to ensure accuracy. 3 Remove the dipstick, then position a suitable container under the transmission, Unscrew the sump drain plug and allow the fluid to drain for at ieast 10 minutes. Refit and tighten the drain plug when the fluid has completely drained.

A


Warning: The transmission fluid may be very hot and precautions must be taken to avoid scalding.
4 Clean around the transmission sump mating flange. Unboll and remove the sump and remove the gasket. 5 Remove the two bolts and withdraw the transmission fluid filter {see illustration). 6 Fit the new filter, and secure It with the two bolts. 7 Refit the sump using a new gasket, then
_
lower the vehicle to the ground, 8 Fill the transmission with the specified quantity of fluid via Ihe dipstick tube, using a funnel with a fine mesh filter. 9 Run the engine to normal operating temperature, then check the fluid level as described In Weekly checks. 10 Dispose of the old fluid safely.
26.2 Transmission filler/level plug location 28.5 Automatic transmission fluid filter retaining bolts

Maintenance procedures - diesel models ib.?
Every 10 000 miles (15 000 km) or 12 months
5 Brake warning lamp operation check 1
1 With Ihe ignition Key inserted and turned to the MAR position, open the bonnet and depress the button on the top of the brake
fluid
reservoir cap (see illustration). I
As
the button is pressed, the brake warning
lamp
on the instrument panel should light. 3 If Ihe lamp fails to illuminate, check the operation of the level switch using a continuity taster, then refer to Chapter t2, Section 5,
and
check the Instrument panel bulb.
6 Front brake pad check ^
I
1 firmly apply Ihe handbrake, then jack up the front of the car and support it securely on arie stands (see Jacking and vehicle support). Remove the front roadwheels. 2 Using a steel rule, measure the thickness of
the
friction material of the brake pads on both brakes. This must not be less than 1.5 mm. Ctefc the thickness of the pad friction material through the hole on the front of the caliper
|see
lustration), 3
For a
comprehensive check, the brake pads should be removed and cleaned. The operation of the caliper can then also bo checked, and the condition of the brake disc iteeil can be fully examined on both sides. Refer to Chapter 9 for further Information. 4 If any pad's friction material Is worn to the specified thickness or less, all lour pads must to renewed as a set. Refer to Chapter 9. 5 On completion refit the roadwheels and lower the car to the ground.
7 Underbody sealant check f^
1 Jack up the front and rear of the car and support on axle stands (see Jacking and
vehicle
support). Alternatively position the car over
an
Inspection pit. 2 Check the complete underbody, wheel housings and side sills for corrosion and/or damage to the underbody sealant. If evident,
rapairi

8
Hose
and fluid leak check
1 Visually inspect the engine Joint faces. g3skets and seals for any signs of water or oil leaks. Pay particular attention to the areas
5.1 Depress tho button on the top of the brake fluid reservoir cap
around the camshaft cover, cylinder head, oil filter and sump joint faces. Bear in mind that, over a period of time, some very slight seepage from these areas is to be expected -what you are really looking for is any indication of a serious leak (see Haynes Hint). Should a teak be found, renew the offending gasket or oil seal by referring to the appropriate Chapters In this manual, 2 Also check the security and condition of all the engine-related pipes and hoses. Ensure thai all cable-ties or securing clips are In place and in good condition. Clips which are broken or missing can lead to chafing of the hoses, pipes or wiring, which could cause more serious problems In the future. 3 Carefully check the radiator hoses and heater hoses along their entire length. Renew any hose which is cracked, swollen or deteriorated. Cracks will show up better If the hose is squeezed. Pay close attention to the hose clips that secure the hoses to the cooling system components. Hose clips can pinch and puncture hoses, resulting in leaks. 4 Inspect all the cooling system components (hoses. )olnt faces etc.) for leaks. A leak in the cooling system will usually show up as white or rust-coloured deposits on the area adjoining the leak, Where any problems of this nature are found on system components, renew the component or gasket with reference to Chapter 3. 5 With the vehicle raised, inspect the fuel tank and filler neck for punctures, cracks and other damage, The connection between the filler neck and tank is especially critical. Sometimes a rubber filler neck or connecting hose will leak due to loose retaining clamps or deteriorated rubber. 6 Carefully check all rubber hoses and metal fuel lines leading away from the fuel tank. Check for loose connections, deteriorated hoses, crimped lines, and other damage. Pay particular attention to the vent pipes and hoses, which often loop up around the filler neck and can become blocked or crimped. Follow the lines to the front of the vehicle, carefully Inspecting them all the way. Renew damaged sections as necessary.
6.2 Check the thickness of the pad friction material through the hote on the front of the caliper
7 With the vehicle raised, check along the length of the underside for leaks from the metal brake lines, caused by damage or corrosion. 8 At each front brake caliper, check the area around the brake pipe unions and the bleed nipples for hydraulic fluid leakage, 9 Remove the front roadwheels and chock for fluid leakage from the area around the caliper piston seal. Check that the tip of the piston dust seal is correctly located in its groove. If it has been displaced, the brake caliper should be removed and overhauled as described in Chapter 9, to check for internal dirt Ingress or corrosion. 10 Check the area surrounding the master cylinder and vacuum servo unit for signs of corrosion, Insecurity or hydraulic fluid leakage. Examine the vacuum hose leading to the servo unit for signs of damage or chafing. 11 From within the engine compartment, check the security of all fuel hose attachments and pipe unions, and Inspect the fuel hoses and vacuum hoses for kinks, chafing and deterioration. 12 Where applicable, check the condition of the power steering fluid hoses and pipes.
A leak in the cooling system will usually show up as white or rust coloured deposits on the area adjoining the leak.

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

2B*4 DOHC (16-valve) petrol engine in-car repair procedures
4.8 Undo three bolts and romove tho crankshaft pulley from the sprocket
Crankshaft setting toot fabrication 7 To make Ihe crankshafl setting tools, four old spark plugs will be required, together with four lengths of dowel rod. The length of each dowel rod is not critical, bul It must be long enough to protrude about 100 mm above the top of the cylinder head extension when resting on top of a piston located half way down its bore. What is critical, however, is that all four do wo I rods must be exactly the same length. 8 Break off the ceramic upper section of each plug and remove the centre electrode and earth tip. The easiest way to do this is to mount each spark plug in a vice (attar removing the ceramic uppor plug section) and drill a hole down through ihe centre of the plug. The diameter of Ihe drill bit should be the same as Ihe diameter of Ihe dowol rod to be used. When finished you should have four spark plug bodies and four equal length dowel rods which will slide through the centre of the spark plugs.
3 Cylinder compression test
1 When engine performance is down, or it misfiring occurs which cannot be attnbuted to the Ignition or fuel systems, 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 bofore any other symptoms become apparent.
4.10 Undo the upper timing cover upper retaining bolt, and the rear retaining boll
4.9 Undo the retaining bolt in the centre of the lower timing cover
2 The engine must be fully warmed-up to normal operxrtrfjg temperature, the battery must be fully charged, and all the spark plugs muse be removed (Chapter 1A>. The aid of an assistant wilt also be required. 3 Disable the ignition system by discon-necting the LT wiring plugs to the Ignition coils. 4 Fit a compression tester to the No t cylinder 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 h.ghest reading obtained 6 Repeat the test on the remaining cylinders, recording Ihe pressure in each. 7 All cylinders should produce very similar pressures; any excessive difference indicates Ihe existence of a fault. Note that the compression should build up quickly in a healthy engine; low compression on (he 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 tho cause). 6 If the pressure in any cylinder is very low, carry out the following test to isolate the cause. Introduce a teaspoonful of dean oil into that cylinder through its spark plug hole and repeal the lest. 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 blown 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 Ihem; the presence of coolant in the engine oil will confirm this. 11 If one cylinder is about 20 percent lower than the others and the 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 §
General information 1 The luncUon of the timing belt Is to drive the camshafts and coolant pump. Should the bell slip or creak in service, the valve timing will be disturbed and piston-to-valve contact wiu occur, resulting in serious engine damage. 2 The timing belt should be renewed at 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 coolam pump at the same time (oheck for signs of coolant leakage). This may avoid the need to remove the timing belt again at a later stage, should the coolant pump fail. 4 Before carrying out this procedure, it will be necessary to obtain or fabricate suitable camshaft locking tools and piston positioning tools as described in Section 2. The procedures contained In this Section depict the use of the home-made alternative tools described in Section 2. which were fabricated In the Haynes workshop. If the manufacturers tools are being used instead, the procedures are virtually identical. Oo not attempt to remove the timing bell unless the special totfs or their alternatives are available.
Removal 5 Disconnect the battery negative terminal (refer to Disconnecting the battery in the Reference Section of Ihis manual). 6 Remove the auxiliary drivebelt(s) as described In Chapter 1A. 7 Remove the air cleaner, Inlet air duct and resonator as desenbed In Chapter 4B. 8 Undo the three bolts and remove the crankshaft pulley from the sprocket (see illustration). 9 Undo the retaining bolt In the centre of the lower liming cover (see illustration). 10 Undo tho uppor timing cover upper retaining bolt, and the rear retaining bolt located above the alternator (see illustration). 11 Release the crankshaft TDC sensor wiring from the clip on the upper timing cover, then withdraw the cover slightly and slide Ihe wiring plug and socket from the liming cover slot (see illustrations). 12 Release the TDC sensor wiring from the periphery ol the upper and fower timing covers and remove both covers (see Illustrations). 13 Free the accelerator inner cable from the throttle cam, remove the outer cable spring dip, then pull the outer cable out from its mounting bracket rubber grommet. 14 From the side of the throttle body, disconnect the wiring connectors from the

2B*5 DOHC (16-valve) petrol engine in-car repair procedures
4.11a Release the crankshaft TDC sensor wiring from the clip on the upper timing cover... throttle potentiometer and the Idle control stepper motor. Disconnect the coolant temperature sensor wiring connector located
in
the inlet manifold below the throttle body,
end
disconnect the brake servo vacuum hose. 15 Disconnect the wiring connectors for the fuel injector harness and the intake air temperature/pressure sensor, then fcconnect the fuel pressure regulator vacuum hose and the EVAP purge valve hose. 18 Undo the two bolts securing the plastic mlet manifold upper section to the lower section. Release the spark plug HT lead from the location groove in the manifold upper wctton, then lift the upper section, complete
»ith
throttle body, off the engine. Recover the 0-rngs from the manifold ports. 17 Unscrew the two bolts securing the fuel
4£1a Screw the spark plug bodies of the homo-made piston positioning tools into each spark plug hole ...
4.21b ... place a suitable washer or similar into the recess to keep the dowel rod vertical...
4.11b ... then slide the wiring plug and socket from the timing cover slot
rail assembly to the inlet manifold lower section, then carefully pull the Injectors from the manifold. Lift the fuel rail and Injector assembly, with fuel hoses still connected, and position it to one side. 16 Undo the bolts securing the engine management ECU mounting brackets to the body and move the ECU to one side without disconnecting the wiring connector. 19 Remove the spark plugs as described in Chapter 1A. 20 Unscrew the two sealing plugs from the front and rear of the cylinder head extension to enable the camshaft locking tools to be inserted. 21 Screw the spark plug bodies of the home-made piston positioning tools into each spark plug hole and insert the dowel rods into each body. To keep the dowel rods vertical, locate a suitable washer or similar over Ihe rod and into the recess at the top of the spark plug hole. In the photos shown here, an old valve stem oil seal housing was used but anything similar will suffice (see illustrations). 22 Using a socket on the crankshaft sprocket centre bolt, turn the crankshaft in the normal direction of rotation until all four dowel rods are protruding from the top of the cylinder head extension by the same amount. As the engine is turned, two of the rods will move up and two will move down until the position is reached where they are all at the same hoight. The best way to check this is to place a straight edge along the top of the rods and turn the crankshafl very slowly until the
4.21c ... then insert the dowel rods
4.12b ... and lower timing covers
straight edge contacts all four rods (see illustration). 23 When all four rods are at the same height, all the pistons will be at the mid-point of their stroke. Using a screwdriver or similar inserted into the front timing hole in the cylinder head extension, check that the timing slot in the exhaust camshaft is approximately aligned with the liming hole. If the camshaft slot cannot be felt, turn the crankshaft through one complete revolution and realign the dowel rods using the straight edge. Check again for the camshaft slot. Note that although the pistons can be at the mid-point of their stroke twice for each cycle of the engine, the camshaft slots will only be positioned correctly once per cycle. 24 With the pistons correctly set, it should now be possible to screw in the camshaft
4.22 Place a straight edge along the top of the rods and turn the crankshaft until the straight edge contacts ail four rods