sensor FIAT PUNTO 1996 176 / 1.G Workshop Manual

1A»1
Chapter
1
Part A:
Routine maintenance & servicing - petrol models
Contents

Air
filter renewal 18 Automatic transmission filter and fluid change 2B Auxiliary dr cmI
and filter renewal 3 Evaporative loss system check 27 Exhaust system check 8 From brake pad check 5 Fuel filter renewal 17 Headlight beam adjustment 23 Hinge and lock lubrication 22
Hose and fluid leak check 7 Idle speed and CO content check and adjustment .11 Ignition system check 20 Introduction 1 Lambda/oxygen sensor check 25 Manifold mounting check 16 Manual transmission oil level check 26 Manual transmission oil renewal .32 Pollen filter renewal 10 Rear brake shoe check 29 Regular maintenance 2 Road test 24 Spark plug renewal 19 Steering and suspension check 12 Timing belt renewal 30 Underbody sealant check 6 Valve clearance check and adjustment 15
Degrees of difficulty
Easy, suitable for ^ novice with little experience ^
Fairty easy, suitable for beginner with ^ some experience
FaMy difficult, ^ sitable for competent jj^ DIY mechanic ^
Difficult, suitable for experienced DIY aJ mechanic ^
Very difficult, ^ suitable for expert DIY or professional ^
expert22 fl/ia http://rutracker.org

Maintenance schedule - petrol models 1A.3
The maintenance Intervals in this manual are provided with the assumption that you, not the dealer, will be carrying out the work. These axe the minimum maintenance intervals recommended by us for vehicles driven daily.
if 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 Q Refer to Weekly checks
Every 5000 miles (7500 km) or
6 months - whichever comes first • Renew the engine oil and filter (Section 3)
Note: Frequent oil and fitter changes am good tor the engine. We recommend changing the oil at the mileage specified here, or at least
twice
a year if the mileage covered Is a less.
Every 10 000 miles (15 000 km) or
12 months - whichever comes first
In
addition to the items listed above, cany out the following: Q Check the operation of the brake warning lamp (Section 4) • Check the front brake pads for wear (Section 5) • Check the underbody and sealant for damage (Section 6) • Hose and fluid leak check (Section 7) • Check the condition of the exhaust system and its mountings (Section 8) • Check the condition of the driveshaft gaiters (Section 9) • Renew pollen filter (Section 10) • Check exhaust gas content and idle speed (Section 11) • Check the steering and suspension components for condition and security (Section 12)
Every 20 000 miles (30 000 km) or
2 years - whichever comes first
In
addition to the Items listed above, carry out the following: • Check and if necessary adjust the tension of the auxiliary drlvebelt(s) (Section 13) • Check the freeplay and height of the clutch pedal (Section 14) • Check and if necessary adjust the valve clearances (Section 15) HI Check and if necessary tighten inlet and exhaust manifold mountings (Section 16) • Renew the fuel filter (Section 17) D Renew the air filter element (Section 18) O Renew the spark plugs (Section 19) • Check the condition of the HT cables (Section 20) • Check the engine management system (Section 21) Q Lubricate all hinges and locks (Section 22) O Check the headlight beam adjustment (Section 23) • Carry out a road test (Section 24)
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 the operation of the Lambda sensor (Section 25) • Check and if necessary top-up the manual transmission oil level (Section 26) • Check the operation of the evaporative loss system (Section 27) • Automatic transmission inner filter and fluid renewal (Section 28)
Every 40 000 miles (60 000 km) or
4 years - whichever comes first In addition to the items fisted above, carry out the following: • Check the rear brake shoes for wear (Section 29) • Renew the timing belt (Section 30)"
*Noto: Although the normal interval for timing belt renewal is 70 000 miles (105 000 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, ie. malniy short Journeys or a let of stop-start driving. The actual belt renewal Interval Is therefore very much up to the individual owner, but bear in mind that severe 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 crankcase emission control system (Section 31)
Every 80 000 miles (120 000 km) • Renew the manual transmission oil (Section 32)
Every 2 years
(regardless of mileage) • Renew the engine coolant (Section 33) • Renew the brake fluid (Section 34)

Every 10 000 miles - petrol models ia.q
10 Pollen filter renewal
1 The pollen filter (where fitted) is located under the engine bulkhead cover panel. 2 Refer to Chapter 12 and remove both svindscreen wiper arms. 3 Unclip the rubber
seal
from the relevant end of
the
top of the engine compartment bulkhead. 4 Unscrew the retaining fastener screws and pull out the fasteners securing the bulkhead cover panel in position. Release the cover panel Irom the base of the windscreen and remove it from the vehicle. 5 Pivot the pollen filter cover upwards and away then release the retaining clips and withdraw the filter from its housing (see illustration). 6 Wipe clean the filter housing then fit the new filter. Clip the filter securely in position and refit the cover. 7 Refit the trim cover, securing it in position with Ihe fasteners, and seat the rubber seal on
the
bulkhead.
11 Idle speed and ^
CO
content check J and adjustment ^
1 The idle speed is controlled by the ECU via a stepper motor located on the side of the throttle body and is not adjustable. 2 The exhaust gas oxygen content is constantly monitored by the ECU via the Lambda sensor, which is mounted in the exhaust down pipe. The ECU then uses this information to modify the injection timing and duration to maintain the optimum air/fuel ratio.
3 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 the idle speed. However, if these are found to be in need of adjustment, the car must be taken to a suitably-equipped Fiat dealer for testing using the special test equipment which is plugged into the diagnostic connector.
12 Steering and ^ suspension check
front suspension and steering check 1 Raise the front of the vehicle, and securely support it on axle stands (see Jacking and
vehicle support).
2 Inspect the balljoint dust covers and the steehng rack-and-pinion gaiters for spirts, chafing or deterioration. Any wear of these will cause loss of lubricant, together with dirt and water entry, resulting in rapid deterioration of the balljoints or steering gear. 3 On vehicles with power steering, check the fluid hoses for chafing or deterioration, and the pipe and hose unions for fluid leaks. Also check for signs of fluid leakage under pressure from the steering gear rubber gaiters, which would indicate failed fluid seals within the steering gear. 4 Qrasp the roadwheel at the 12 o'clock and 6 o'clock positions, and try to rock it (see illustration). Very slight free play may be felt, but if the movement is appreciable, further investigation Is necessary to determine the source. Continue rocking the wheel while an assistant depresses the footbrake. If the movement is now eliminated or significantly reduced, it is likely that the hub bearings are at fault. If the free play is still evident with the footbrake depressed, then there is wear in the suspension joints or mountings. 5 Now grasp the wheel at the 9 o'clock and 3 o'clock positions, and try to rock it as before. Any movement felt now may again be caused by wear in the hub bearings or the steering track-rod balljoints. If the inner or outer balljoint is worn, the visual movement will be obvious.
12.4 Rocking a roadwheel to check for wear in the steering/suspension components 6 Using a large screwdriver or flat bar, check for wear in the suspension mounting bushes by levering between the relevant suspension component and its attachment point. Some movement is to be expected as the mountings are made of rubber, but excessive wear should be obvious. Also check the condition of any visible rubber bushes, looking for splits, cracks or contamination of the rubber. 7 With the car standing on its wheels, have an assistant tum the steering wheel back and forth about sn eighth of a turn each way. There should be very little, if any. lost movement between the steering wheel and roadwheels. If this is not the case, closely observe the joints and mountings previously described, but in addition, check the steering column universal joints for wear, and the rack-and-pinion steering gear itself.
Suspension strut/ shock absorber check 8 Check for any signs of fluid leakage around the suspension strut/shock absorber body, or from the rubber gaiter around the piston rod. Should any fluid be noticed, the suspension strut/shock absorber is defective internally, and should be renewed. Note: Suspension struts/shock absorbers should always be renewed in pairs on the same axle. 9 The efficiency of the suspension strut/shock absorber may be checked by bouncing the vehicle at each corner. Generally speaking, ihe body will return to its normal position and stop after being depressed. If it rises and returns on a rebound, the suspension strut/shock absorber is probably suspect. Examine also the suspension strut/shock absorber upper and lower mountings for any signs of wear.
Every 20 000 miles (30 000 km) or 2 years
13 Auxiliary drivebelt{s) check % and renewal ^
Note: Fiat specify the use of a special tool to cooectfyset the drivebelt tension. If access to ibis equipment cannot be obtained, an
approximate setting can be achieved using the method described below. If the method described is used, the tension should be checked using the special tool at the earliest possible opportunity. 1 Depending on equipment fitted, one. two or three auxiliary drivebelts may be fitted. The alternator, power steering pump and air
conditioning compressor, as applicable, are each driven by an Individual drivebelt.
Checking 2 Disconnect the battery negative terminal (refer to Disconnecting the battery in the Reference Section of this manual). 3 Firmly apply the handbrake, then jack up

ia.io Every 20 000 miles - petrol models
the front of the car and support It securely on axle stands (see Jacking and vehicle support}. 4 Remove the nght-hand front wheel. 5 Remove the inner cover from under the right-hand wheeiarch for access to the right-hand side of the engine. 0 Using a socket on the crankshaft sprocket boll, rotate the crankshaft so that the full length of the auxiliary drlvebelt(s) can be examined. Look for cracks, splitting and fraying on the surface of the belt: check also for signs of glazing (shiny patches) and separation of the belt plies. If damage or wear Is visible, the relevant belt should be renewed. 7 If the condition of the belt Is satisfactory, check Ihe drivebeit tension as described below.
Renewal
Alternator drivebeit Note: On certain models with power steering but without air conditioning, it will be necessary to remove the power steering pump drivebeit ffrst, as described below. 8 Where fitted, undo the bolts and remove the belt guard from the alternator. 9 Loosen the pivot and adjustment bolts then swivel the alternator towards the engine and slip off the drivebeit. 10 Unbolt and remove the crankshaft sensor from Ihe front of the engine (refer to Chapter 4A. Section 5, if necessary). 11 Remove the drivebeit from the engine. 12 When renewing a drivebeit. ensure that the correct type is used. Fit the belt around the two pulleys then swivel the alternator outwaids to take up any slack in the betL Adjust the tension correctly as described below. Power steering pump drivebeit 13 Slacken the bolts securing the power steering pump to the mounting bracket. 14 Slacken the adjusting bolt locknut and turn the adjusting boit until all the tension is removed from the drivebeit. 15 Undo the bolts and remove the pultey guard from the power steering pump then slip the drivebeit off (he pulleys. 18 Ensuring that the correct type of drivebeit is used, fit the belt around the pulleys and turn the adjusting bolt to just take up the slack in the belt. Adjust the tension correctly as described below. Air conditioning compressor drivebeit 17 Remove the alternator and power steering pump dnvebelts as described previously. 18 Slacken the bolts securing the compressor to the mounting bracket. 19 Slacken the adjusting bolt locknut and turn the adjusting bolt until alt the tension is removed from the drivebeit, then slip the belt off the pulleys. 20 Ensuring lhat the correct type of drivebeit is used, fit the belt around the pulleys and turn the adjusting bolt to just take up the slack In the belt. Adjust the tension correctly as described below.
15.7 Checking a valve clearance with a feeler blade
Tensioning 21 Correct tensioning of the belt will ensure that it has a long life. A belt which Is too slack will slip and perhaps squeal. Beware, however, of overtightening, as this can cause wear in the alternator, power steering pump or air conditioning compressor bearings. Note: Fiat recommend use of their special tensioning tool however the fallowing procedure will set the tension correctly. 22 The belt(s) should be tensioned so that, under firm thumb pressure, there is approximately 5.0 mm of free movement at the mid-point between the pulleys. To adjust the alternator drivebeit, slightly tighten the adjustment bolt then swivel the alternator outwards until tne beft tension Is correct. Fully tighten the adjustment bolt followed by the pivot bolt then refit the rpm sensor. 23 On models with power steering and/or air conditioning, fit the relevant drivebeit over the pulleys then turn the adjusting bolt until the tension is correct. Secure the adjusting bolt by tightening Ihe locknut, then tighten the remaining mounting bolts. Refit any remaining dnvebelts and all the components removed. 24 Refit the inner cover and wheel, lower the vehicle to the ground, then reconnect the battery negative terminal,
14 Clutch adjustment check
Refer to Chapter 8. Section 2.
15.11 Using a modified C-spanner and e screwdriver to remove a shim
15 Valve clearance check ^ and adjustment S
Note: The following procedure Is not applicable to 1242 cc,
16-vatve
engines which utilise self-adjusting hydraulic tappets. 1 The importance of having the valve clearances correctly adjusted cannot be overstressed, as they vitally affect the performance of the engine. Adjustment should only be necessary when the valve gear has become noisy, after engine overhaul, or when trying to trace the cause of power loss. The clearances are checked as follows. The engine must be cold for the check to be accurate. 2 Apply the handbrake then jack up the right* hand front of the vehicle and support on an axle stand (see Jacking and vehicle support). Engage 4th gear. The engine can now be rotated by turning the right-hand front road wheel. 3 Remove all spark plugs as described In Section 19. 4 Remove the camshaft cover as described In Chapter 2A. 5 Each valve clearance must be checked when the high point of the cam lobe is pointing directly upward away from the cam follower. 6 Check the clearances In the firing order 1-3-4-2. No
1
cylinder being at the timing bell end of the engine. This will minimise the amount of crankshaft rotation required. 7 Insert the appropriate feeler blade between the heel of the cam and the cam follower shim of the first valve (see illustration). II necessary alter the thickness of the feeler blade until it is a stiff, sliding fit. Record the thickness, which will, of course, represent the valve clearance for this particular valve. 8 Tum the engine, check the second valve clearance and record it. 9 Repeat the operations on all the remaining valves, recording their respective clearances. 10 Remember that the clearance for Inlet and exhaust valves differs • see Specifications. Counting from the timing cover end of the engine, the valve sequence is: tnlet 2-4-5-7 Exhaust 7-3-6-$ 11 Where clearances are incorrect, the particular shim will have to be changed. To remove the shim, turn the crankshaft until the high point of the cam Is pointing directly upward. The cam follower will now have to be depressed so that the shim can be extracted. Special tools are available from your Fiat dealer to do the job, otherwise you will have to make up a forked (ever to locate on the rim of the cam follower. This must allow room for the shim to be prised out by means of the cut-outs provided in the cam follower rim {see illustration). 12 Once the shim is extracted, establish its thickness and change It for a thicker or thinner one to bring the previously recorded

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

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

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

2B*7 DOHC (16-valve) petrol engine in-car repair procedures
35 Slacken the tensioner pulley retaining nut and reposition the tensioner to align the
mobile
indicator with the fixed reference mark
on the
pulley face (see illustration). Hold the
pdley in
this position and tighten the retaining
nut to the
specified torque. 36 Turn the crankshaft through a further two complete turns In the normal direction of rotation. Check that the timing is correct by alining Ihe piston positioning tools and
camshaft
locking tools as described previously. 37 When all is correct, remove the setting rri
locking
tools and refit the sealing plugs to 1ft© cylinder head extension, using new 0-
nr^s if
necessary. Tighten the plugs securely. 38 Refit the spark plugs as described in Chapter 1A. 39 Refit Ihe ECU and secure with Ihe mooning bolts. 40
Renew the
injector O-ring seals, smear them Kith
8 little
Vaseline then locate the injectors and tef rail onto the inlet manifold lower section.
Saute Ihe fuel rail
with the two retaining bolts. 41 Relit the inlet manifold upper section using new sealing O-rlngs If necessary and
sectre
with the two bolts. 42 Reconnect the wiring connectors for the tot injector harness and the intake air temp-erature/pressure sensor, then connect the fuel pressure regulator vacuum hose and tha
EVAP
purge valve hose. 43 Reconnect the wiring connectors for the ihrottls potentiometer, idle control stepper motor and coolant temperature sensor. Reconnect the brake servo vacuum hose. 44 Refit and adjust the accelerator cable as described in Chapter 4B. 46 Refit the upper and lower timing belt
covers
together with the TDC sensor wiring. 46 Refit the crankshaft pulley and tighten the
three
retaining bolts securely. 47 Refit the air cleaner. Inlet air duct and resonator as described in Chapter 4B. 48
Refit
tha auxiliary drivebelt(s) as described i/t Chapter 1A, then reconnect the battery
S Timing belt tensioner
and
sprockets -
removal
and refitting

Timing
belt tensioner
Removal I
Remove
the timing belt as described in
Section
4. 1 Completely unscrew the tensioner nut and Wiethe tensioner off the mounting stud-Inspection
3 Wipe
the tensioner clean but do not use Kfrents that may contaminate the bearings.
Spin
the tensioner pulley on its hub by hand.
Sfcfl
movement or excessive freeplay is an rcfceticn of severe wear: the tensioner is not 3 serviceable component, and should be nnewsd.
4.33 Holding the camshaft sprocket with the tool described previously while tightening the sprocket bolt Refitting 4 Slide the tensioner pulley over the mounting stud and fit the securing nut. 5 Refit the timing belt as described in Section 4. Camshaft sprocket Removal 6 Remove the timing belt as described in Section 4. 7 Unscrew the bolt and slide the sprocket from the end of the camshaft. Inspection 8 With the sprocket removed, examine the camshaft oil seal for signs of leaking. If necessary, refer to Section 6 and renew it. 9 Check the sprocket teeth for damage. 10 Wipe clean the sprocket and camshaft mating surfaces. Refitting 11 Locate the sprocket on the end of the camshaft, then refit the retaining boll finger tight only at this stage. 12 Refit the timing belt as described in Section 4.
Crankshaft sprocket Removal 13 Remove the timing bell as described In Section 4. 14 Working beneath the engine, unbolt and remove the flywheel lower cover, then hold the flywheel stationary preferably using a tool which engages the flywheel starter ring
<

Alternatively have an assistant engage a wide-bladed screwdriver with the starter ring gear. 15 Unscrew the crankshaft sprocket retaining bolt and slide the sprocket off the end of the crankshaft. The sprocket may have an integral location key on its inner face, or a separate key which locates In a groove in the crankshaft nose may be fitted. Inspection 16 With the sprocket removed, examine the crankshaft oil seal for signs of leaking. If necessary, refer to Section 7 and renew it. 17 Check the sprocket teeth for damage. 18 Wipe clean the sprocket and crankshaft mating surfaces. Refitting 19 Slide the sprocket onto the crankshaft making sure
11
engages the integral key or separate key, then refit the bolt and washer and tighten the bolt to the specified torque while holding the crankshaft stationary using the method described in paragraph 14. 20 Refit the timing belt as described in Section 4.
6 Camshaft
oil
seal -renewal
1 Remove the timing belt and camshaft sprocket as described in Sections 4 and 5. 2 Punch or drill a small hole in the oil seal. Screw a self-tapping screw into the hole, and pull on the screws with pliers to extract the seal. 3 Clean the seal housing, and polish off any burrs or raised edges, which may have caused the seal to fall in the first place. 4 Lubricate the lips of the new seal with clean engine oil, and drive it into position until It seats on its locating shoulder. Use a suitable tubular drift, such as a socket, which bears only on the hard outer edge of the seal. Take care nof to damage the seal lips during fitting. Note that the Seal lips should face inwards. 5 Refit the camshaft sprocket and timing belt as described in Sections 5 and 4.
7 Crankshaft oil seats -renewal I
4.35 Position the tensioner so that the mobile Indicator (1) is aligned with the fixed reference mark (2)
Front (right-hand side) oil seal 1 The front oil seal is located in the oil pump on the front of the crankshaft. Remove the timing belt as described in Section 4 and the crankshaft sprocket as described in Section 5. 2 Using a hooked Instrument, remove the oil seal from the oil pump casing taking care not to damage the surface of the crankshaft. 3 Clean the seating in the housing and the surface of the crankshaft. To prevent damage to the new oil seal as it is being fitted, wrap some adhesive tape around the end of the crankshaft and lightly oil it.

DOHC (16-valve) petrol engine in-car repair procedures 2B*11
camshaft cover plate... 25 Locate the cam follower retaining tools in position and refit the cylinder head extension
as
described In Section 8.

10
Cylinder head - &
removal and
refitting S
Removal Note; The cylinder head bolts are of special
sekned
design and a Fiat tool should be
obtained
to unscrew them. A Ton key will not
JSt however
in practise It was found that a dose-httlng Alien key could be used as an itemative. 1 Drain the cooling system as described in Chapter 1A. 2 Remove the cylinder head extension as oescAbed
m
Section 8. 3 Disconnect the radiator hose from the thermostat housing on the left-hand end of
Ihe
cylinder head. 4 Disconnect the heater hose from the outlet
at the
rear of the cylinder head. 5 Disconnect the coolant temperature sensor md temperature gauge sensor wiring plugs
torn
the left-hand end of the cylinder head. 9 Undo the engine oil dipstick tube bracket retaining bolt and the two bolts securing the wing harness support clips to the inlet marriold lower section. 7 Undo Ihe retaining nuts and separate the ixhaust system front pipe from the exhaust manifold flange.
8
Check that nothing remains attached to the cinder head likely to impede removal. It Is assumed that the head will be removed complete with exhaust manifold and inlet manifold lower section. 9 Unscrew the cylinder head bolts half a turn K
e
time in the reverse order to that shown in (lustration 10.20a. When the bolts are free. «mwe them from their locations.. Id Lift the cylinder head from the block. If it is stuck tight rock the head to break the joint by mans of the manifolds. On no account drive
levers
into the gasket Joint, nor attempt to tap tf« head sideways, as it is located on positioning dowels. 11 Remove and discard the cylinder head gasket.
JK'
l^. 9.22b ... then apply RTV gasket sealant to the cover plate contact face 12 Refer to Chapter 20 for cylinder head dismantling and inspection procedures. Preparation for refitting 13 The mating faces of the cylinder head and cylinder block must be perfectly dean before refitting the head. Use a hard plastic or wooden scraper to remove all traces of gasket and carbon; also clean the piston crowns, Take particular care when cleaning the piston crowns as the soft aluminium alloy is easily damaged. Make sure that the carbon is not allowed to enter the oil and water passages -this Is particularly important for the lubncahon system, as carbon could block the oil supply to the engine's components. Using adhesive tape and paper, seal the water, oil and bolt holes in the cylinder block. To prevent carbon entering the gap between the pistons and bores, smear a little grease In the gap. After cleaning each piston, use a small brush to remove all traces of grease and carbon from the gap. then wipe away the remainder with a clean rag. Clean all the pistons in the same way. 14 Check the mating surfaces of the cylinder block and the cylinder head for nicks, deep scratches and other damage. If slight, they may be removed carefully with a file, but If excessive, machining may be the only alternative to renewal. If warpage of the cylinder head gasket surface Is suspected, use a straight-edge to check it for distortion. Refer to Part 0 of this Chapter if necessary. 15 Check the condition of the cylinder head bolts, and particularly their threads, whenever they are removed. Wash the bolts In a suitable
sequence
9.24 Lubricate the cam followers and place them in position in their respective bores solvent, and wipe them dry. Check each bolt for any sign of visible wear or damage, renewing them if necessary.
Refitting 18 Before refitting the assembled cylinder head, make sure that the head and block mating surfaces are perfectly clean, and that the bolt holes in the cylinder block have been mopped out to clear any oil, 17 The now gasket should not be removed from its nylon cover until required for use. Fit Ihe gasket dry, and make sure that the mating surfaces on the head and block are perfectly clean. 18 Place the gasket on the cylinder block so that the word ALTO can be read from above. 19 Lower the cylinder head onto the block so that it locates on the positioning dowel. 20 The cylinder head bolt threads must be clean and lightly lubricated. Screw the bolts in finger-tight then working progressively and in the sequence shown, lighten all the cylinder head bolts to the Stage 1 torquo setting given In the Specifications, using a torque wrench and a suitable socket. With all the bolts tightened to their Stage 1 setting, working again in the specified sequence, first angle-tighten the bolts through the specified Stage 2 angle, then again through the Stage 3 angle, using a socket and extension bar. It Is recommended that an angle-measuring gauge Is used during this stage ot tightening, to ensure accuracy (see Illustrations). 21 Reconnect the exhaust system front pipe to the manifold using a new flange gasket.
10.20b Tighten the cylinder head bolts to the Stago 1 torque setting ...