check engine FIAT PUNTO 1998 176 / 1.G Manual Online
[x] Cancel search | Manufacturer: FIAT, Model Year: 1998, Model line: PUNTO, Model: FIAT PUNTO 1998 176 / 1.GPages: 225, PDF Size: 18.54 MB
Page 110 of 225
2D*10 Engine removal and overhaul procedures
12.5 Lowering the crankshaft into the crankcase
12.9 Fit tho main bearing caps...
to allow lubricant to circulate. This clearance is impossible to check using feeler blades, however Plastlgauge can be used. This consists of a thin strip of soft plastic that is crushed between the bearing shells and journals when the beanng caps are tightened up. Its width then indicates the size of the clearance gap. 7 Cut off five pieces of Plastlgauge. just shorter than the length of the crankshaft journal. Lay a piece on each journal, in line with its axis (see Illustration). 8 Wipe off the rear surfaces of the new lower half main bearing shells and fit them to the main beanng caps, again ensuring that the locating lugs engage correctly (see illustration). 9 Fit the caps in their correct locations on the bearing saddles, using the manufacturers markings as a guide (see illustration). Ensure lhat Ihey are correctly orientated • the caps should be fitted such that the recesses (or the bearing shell locating lugs are on the same side as those in the bearing saddle. 10 Insert and tighten the bolls until they are
811
correctly torqued (see illustrations). Do not allow the crankshaft to rotate at all whilst ihe Plastlgauge is in place. Progressively unbolt the bearing caps and remove them, taking care not to dislodge the Plastlgauge. 11 The width of the crushed Plastigauge can now be measured, using the scale provided (see illustration). Use the correct scale, as both Imperial and metric are printed. This measurement Indicates the running clearance • compare it with that listed in the Specifications.
21 \ „ 12.7 Lay the Plastigauge on the main bearing journals
t
12.10a ... Insert the bolts...
If tho clearance is outside ihe tolerance, it may be due to dirt or debns trapped under the bearing surface; try cleaning them again and repeat the clearance check. If the results are still unacceptable, re-check Ihe journal diameters and the bearing sizes. Note that if the Plastigauge is thicker at one end. the loumals may be tapered and as such, will require regrinding. 12 When you are satisfied that the clearances are correct, carefully remove the remains of the Plastigauge from the journals and bearings faces. Use a soft, plastic or wooden scraper as anything metallic is likely to damage the surfaces.
Crankshaft • final refitting 13 Lift the crankshaft out of the crankcase. Wipe off the surfaces of the bearings in the crankcase and the bearing caps. Fit the thrust beanngs using grease to hold them in
12.11 Use the special scale card to determine the main bearing running clearance
shell In its cap
12.10b ... and torque-tighten them
position, Ensure they are seated correctly in the machined recesses, with tho oil grooves facing outwards 14 Liberally coat the bearing shells in the crankcase with dean engine oil (see Illustration). 15 Lower the crankshaft into position in the crankcase. 16 Lubricate the lower bearing shells in the main bearing caps with clean engine oil. Make sure that the locating lugs on the shells are still engaged with the corresponding recesses in the caps. 17 Fit the main bearing caps in the correct order and orientation. Insert the bearing cap bolts and hand tighten them only. 18 Working from the centre bearing cap outwards, tighten the retaining bolts to their specified torque. On petrol engines, tighten all the bolts to the first stage, then angle-tighten them to the Stage 2 anglo (see illustration)
12.14 Lubricate the main bearing shells before final assembly
Page 111 of 225
2D*10 Engine removal and overhaul procedures
12.18 Angle-tightening the main bearing cap bolts (petrol engine)
12.Ida Application area for silicone Instant gasket on crankshaft rear oil seal housing (petrol engine) 12.19b Refitting the crankshaft rear oil seal housing (petrol engine)
19 Fit a new oil seal to the crankshaft rear oil seal housing. Apply grease to the seal lips. On 1108 cc petrol engines a conventional gasket Is not used at the oil seal retainer joint face, but a 3 mm diameter bead of RTV (Instant) silicone gasket must be applied as shown -allow at least one hour 1or the gasket to cure before oil contacts it. On all other engines a gasket Is fitted Securely tighten the housing bolts (see Illustrations). 20 Check that Ihe crankshaft rotates freely by turning It by hand. If resistance Is fell, re-check the running clearances, as described above. 21 Carry out a check of the crankshaft endfloat as described at the beginning of Section 8. If the thrust surfaces of the crankshaft have been checked and new thrust washers hove been fitted, then the endfioat should be within specification.
22 Refit the pistons and connecting rods as described in Section 7. 23 Refit the flywheeVdriveplate, and-vibration plate (16-valvo engines), oil pump and pick-up tube, and sump with reference to the relevant Sections of Parts A, B or C of this Chapter.
13 Engine -initial start-up after overhaul and reassembly
1 With the engine refitted In the vehicle, double-check the engine oil and coolant levels. Make a final check that everything has been reconnected, and that there are no tools or rags left In the engine compartment.
Petrol engine models 2 Remove the spark plugs, then disable the
ignition system by disconnecting the LT wiring plug to the ignition colls. 3 Turn the engine on the starter until Ihe oi pressure warning light goes out. Refit ihe spark plugs, and reconnect the LT wiring.
Diesel engine models 4 Disconnect tho wiring from the stop solenoid on the Injection pump, then turn the engine on the starter motor until the oil pressure warning light goes out. Reconnect ihe wire to the stop solenoid. 6 Fully depress the accelerator pedal, turn tho ignition key to its first position and wait tor HHJ preheating warning light to go out.
All models 6 Start the engine, noting that this may take i little longer than usual, due to the fuel system components having been disturbed.
12.19c On diesel engines use a screwdriver to prise out the rear oil seal 12.19d Locate the new oil soalln the housing (diosel engine)... 12.19e ... and use a block of wood to drive it in
12.19f On Diesel engines fit the gasket to the cylinder block ... 12.19g ... then locate the rear oli seal housing... 12.19h ... and Insert the bolts
Page 112 of 225
2D*10 Engine removal and overhaul procedures
7 While the engine is idling, check for fuel, water and oil leaks. Don't be alarmed if there are some odd smells and smoke from parts getting hot and burning off oil deposits, ft Assuming alt is well, keep the engine idling until hot water is felt circulating through the bp hose, then switch off the engine.
9 Recheck the oil and coolant levels as described in Chapter 1A or 16, and top-up as necessary. 10 There is no need to re-tighten the cylinder head bolts once the engine has first run after reassembly. 11 If new pistons, rings or crankshaft
bearings have been fitted, the engine must be treated as new. and run-in for the first 500 miles (800 km). Do net operate the engine al full-throttle, or allow it to labour at low engine speeds in any gear. It is recommended that the oil and filter be changed at the end of this period.
2D
Page 113 of 225
3*1
Chapter 3
Cooling, heating and ventilation systems
Contents
Air conditioning system - general Information and precautions .... 9 Mr conditioning system components * removal and refitting 10 Antifreeze mixture See Chapter 1A or 1B Auxiliary drivebell(s) check and renewal See Chapter 1A or IB Coolant level check See Weekly checks Coolant pump - removal, Inspection and refitting 7 Coolant renewal See Chapter 1A or 1B
Degrees of difficulty
Cooling fan switch - testing, removal and refitting 6 Cooling system hoses • disconnection and renewal 2 Electric cooling fan(s) - testing, removal and refitting 5 General information and precautions 1 Heater/ventilation components • removal and refitting 8 Radiator - removal, inspection and refitting 3 Thermostat - removal, testing and refitting 4
Easy,
suitable foe JS^, novice
with
little experience ^
Fairly
easy,
sutable for beginner witti
some experience
^
Faiilydifltctit,
suitable
for competent
DIY mechanic
^
Difficult,
sutable for & experienced DIY « mechanic ^
VerydMlcult, ^
suitable
for
expert DIY
« or professional
Specifications
General Expansion tank relief valve opening pressure 0.96 bar Coolant pump Impeller-to-casing clearance: Diesel engine models 0.53 to 1.37 mm Petrol engine models 0.4 to 0.9 mm
Thermostat Diesel engine models: Opening temperature: Starts to open 78 to 82*0 Fully open 88°C Maximum valve travel (approximate) 7.5 mm Petrol engine models: Opening temperature: 1108 cc and 1242 cc (8-valve) engines: Starts to open 85 to 89°C Fully open 100°C 1242 cc (16-valve) engines: Starts to open 81 to 85°C Fully open 103°C Maximum valve lift (approximate) 7.5 mm
Electric cooling fan Petrol engine models with single speed fan: Cut-in temperature 90to94°C Cut-out temperature B5 to 89°C Diesel engine models with twin speed fan: Cut-In temperature: Primary fan 86 to 90® C Secondary fan 90 to 94°C Cut-out temperature: Primary fan 81to85°C Secondary fan 85 to 89°C
Torque wrench settings Nm tbfft Coolant pump pulley securing bolts (diesel engine models) 23 17 Coolant pump securing bolts: Diesel engine models 23 17 Petrol engine models 8 6 Coolant pump securing nuts (petrol engine models) 10 7
Page 114 of 225
3*2 Cooling, heating and ventilation systems
1 General information and precautions
Genera/ Information The engine cooling/cabin heating system is ol pressurised type, comprising a coolant pump driven by the camshaft timing belt (petrol engine models) or auxiliary drlvebelt (diesel engine models), a crossllow radiator, a coolant expansion tank, an electric cooling fan, a thermostat, heater matrix, and all associated hoses and switches. The system functions as follows: Ihe coolant pump circulates cold water around the cylinder block and head passages, and through the Inlet manifold, heater matrix and throttle body to the thermostat housing. When the engine Is cold, the thermostat remains closed and prevents coolant from circulating through the radiator. When the coolant reaches a predetermined temperature, the thermostat opens, and the coolant passes through the top hose to the radiator. As the coolant circulates through the radiator, it is cooled by the in-rush of air when the car is in forward motion. The airllow is supplemented by the action of the electric cooling fan. when necessary, As the temperature of the coolant in the radiator drops, it flows to the bottom of the radiator by convection, and passes out through the bottom hose to the coolant pump - the cycle is then repeatod, When the engine is at normal operating temperature, the coolant expands, and some of It is displaced into the expansion tank. Coolant collects In the tank, and ts returned to Ihe radiator when the system cools. On petrol engine models, the expansion tank is integrated into the side of the radiator. On diesel engine models, and certain petrol engine models with air conditioning, the tank is a separate unit, mounted on the right hand side of the engine compartment. On turbo diesel engine models, the coolant is also passed through a supplementary engine oil cooler, to assist In controlling the engine lubricant temperature. Tho electric cooling fan mounted in front of the radiator is controlled by a thermostatic switch. At a predetermined coolant temperature, the swilch/sensor actuates the tan lo provide additional airflow through the radiator, The switch cuts the electrical supply to the Ion when the coolant temperature has dropped below a preset threshold (see Specifications).
Precautions
A
Warning: Do not attempt to remove the expansion tank pressure cap, or to disturb any part of the cooling system, whlio the engine is hot, as then is a high risk of scalding, tf the expansion tank pressure cap must be removed before the
engine and radiator have fulty cooled (even though this is not recommended?, the pressure in the cooling system must first be relieved. Cover the cap with a thick layer of cloth, to avoid scalding, and slowly unscrew the pressuro cap until a hissing sound Is heard. When the hissing stops, indicating that the pressure has reduced, slowly unscrew the pressure cap until it can be removed; If more hissing sounds are heard, wait until they have stopped before unscrewing the cap completely. At all times, keep your face well away from the pressure cap opening, and protect your hands.
A
Warning: Do not allow antifreeze to come into contact with your skin, or with the painted surfaces of the vehicle. Rinse off spills immediately, with plenty of water. Never leave antifreeze lying around in an open container, or In a puddle In the driveway or on the garage floor. Children and pets are attracted by its sweet smell, but antifreeze can be fatal tf ingested.
A
Warning: If the engine is hot, the electric cooling fan may start rotating even if the engine and ignition are switched off. Be careful to keep your hands, hair, and any loose clothing well clear when working In the engine compartment.
2 Cooling system hoses - f&> disconnection and renewal ^
1 The number, routing and pattern of hoses will vary according to model, but the same basic procedure applies. Before commencing work, make sure that the new hoses are to hand, along wilh new hose clips if needed, it is good practice to renew the hose clips at the same time as the hoses. 2 Drain the cooling system, as described in Chapter 1A or 18, saving the coolant if it is fit for re-use. Apply a little penetrating oil onto the hose clips if they are corroded. 3 Release the hose clips from the hose concerned. Three types of clip are used; worm-drive. spring and 'sardine-can'. The worm-drive clip is released by turning its screw anti-clockwise. The spring clip Is released by squeezing Its tags together with pliers, at the same time working the cbp away from the hose stub. The sardine-can clips are not re-usable, and are best cut off with snips or side cutters. 4 Unclip any wires, cables or other hoses which may be attached to the hose being removed. Make notes for reference when reassembling If necessary. 5 Release the hose from its stubs with a twisting motion. Be careful not to damage the stubs on deltcate components such as the radiator, or thermostat housings. If the hose Is stuck fast, the best course is often to cut it off using a sharp knife, but again be careful not to damage the stubs.
6 Before fitting the new hose, smear the stubs with washing-up liquid or a suitable rubber lubricant to aid fitting. Do not use oil or grease, which may attack the rubber. 7 Fit the hose clips over the ends of the hose, then fit the hose over its stubs. Work the hose Into position. When satisfied, locate and tighten the hose dips. 6 Refill the cooling system as described In Chapter 1A or 1B. Run the engine, and chock that there are no leaks. 9 Recheck the tightness of Ihe hose clips on any new hoses after a few hundred miles. 10 Top-up the coolant level if necessary.
3 Radiator -
removal,
inspection and refitting
Removal Note: If leakage is the reason for removing
the
radiator, bear In mind that minor leaks can often be cured using proprietary radiator sealing compound, with the radiator in situ. 1 Disconnect the battery negative terminal (refer to Disconnecting the battery In the Reference Section of this manual). On diesel engine models, unbolt the relay bracket from the side of the battery tray. 2 Drain the cooling system as described In Chapter 1A or 1B. 3 On 1242 cc (16-valve) petrol engine models, remove the air cleaner and Inlet ducts as desenbed In Chapter 4B, 4 Slacken the clips and disconnect Ihe (op and bottom coolant hoses from the radiator. In addition on diesel engine models, and petrol engine models with a remotely-sited expansion tank, disconnect the expansion tank coolant hose from the right hand side ol the radiator (see Illustrations), 5 Unscrew the fixings and lift the plastic trim panel from above the front bumper Unscrew the bolt(s) securing tho radiator to the upper body panel (see Illustration). Note that the radiator and cooling fan assembly share the same upper mounting bolt. 6 Unbolt the cooling fan(e) and shroud assembly from Ihe rear ot the radiator, as described in Section 5.
3.4a Slacken the clip and disconnect the radiator bottom hose
Page 117 of 225
3*2 Cooling, heating and ventilation systems
4 If the motor operates when tested as described, (he fault must lie In the engine wring harness or the temperature sensor. The temperature sensor/switch can be tested as described in Section 6. Any further fault Diagnosis should be referred to a suitably-equipped Fiat dealer - do not attempt to test
Ihe
electronic control unit.
Removal 5 Disconnect the battery negative terminal (refer to D/scon oecf/ng the battery in the Reference Section of this manual). 6 On diesel engine models, unbolt the relay bracket from the side of the battery tray to improve access. On 1242 cc {16-valve) petrol engine models, remove the air cleaner and
inset
ducts as described in Chapter 4B. 1 Disconnect the motor wiring connectorfs). 8 Unbolt the shroud from the rear of the ratiator. then lift out the cooling fan assembly. Refitting 9 Refitting is a reversal of removal
6 Cooling fan switch -testing, removal and refitting ^
Testing 1 The switch is threaded into the lower left
nand
comer of the radiator. 2 The switch can be tested by removing it,
and
checking that the switching action occurs
at
the correct temperature {heat the sensor in a container of water, and monitor the temperature with a thermometer). 3 There should be no continuity between the switch terminals, until Ihe specified cooling fan cut-In temperature Is reached, when continuity (and zero resistance) should exist between the terminals.
Removal 4 Disconnect the battery negative terminal refer to Disconnecting the battery in the Reference Section of this manual). 5 Allow the engine to cool completely, then drain the cooling system as described in Chapter 1Aor 1B. 6 Disconnect the wiring plug from the sensor.
bolts...
7 Carefully unscrew the sensor and. whore applicable, recover the sealing ring. Refitting 8 If the sensor was originally fitted using sealing compound, clean the sensor threads thoroughly, and coat them with fresh sealing compound. 9 If the sensor was originally fitted using a sealing ring, use a new sealing ring on refitting. 10 Refitting is a reversal of removal, but refill the cooling system as described in Chapter 1A or 18. 11 On completion, start the engine and run it until it reaches normal operating temperature. Continue to run the engine until the cooling fan cuts in and out correctly.
7 Coolant pump • & removal, inspection 5 and refitting
Removal
Petrol engine models 1 Disconnect the battery negative terminal (refer to Disconnecting the battery in the Reference Section of this manual). 2 Drain the cooling system and remove the auxiliary drivebett(s) as described In Chapter 1 A. 3 Remove the timing belt as described In Chapter 2A or 28. 4 Unscrew the securing bolts/nuts, and withdraw the coolant pump (see illustrations).
7.9b ... and lift off the pulley (diesel engine)
(petrol engine) If the pump Is stuck, tap it gently using a soft-faced mallet - do not lever between the pump and cylinder block mating faces.
Diesel engine models 5 Disconnect the battery negative terminal (refer to D/s connecting the battery in the Reference Section of this manual). 6 Drain the cooling system as described in Chapter 1B. 7 Remove the auxiliary drivebelt(s) as descnbed In Chapter 1B. 6 On models fitted with power steenng, refer to Chapter 10 and remove the power steering pump from its mountings; this can be achieved without disconnecting the power steering fluid hoses from the pump. Tie the pump away from the work area, taking care to avoid kinking the fluid hoses. 9 Unscrew the securing bolts, and remove the coolant pump pulley. It will be necessary to counterhold the pulley In order to unscrew the bolts, and this is most easily achieved by wrapping an old drivebelt tightly around the pulley to act in a similar manner to a strap 3 wrench. Alternatively, a stout screwdriver can be braced between two of the pulley bolts while the third is slackened (see illustrations). 10 Disconnect ihe bypass hoses from the coolant pump outlet stubs. 11 Unscrew the securing bolts, and withdraw the coolant pump assembly. Note that the pump must be detached from the transfer pipe than runs behind the cylinder block to the thermostat housing (see illustration). The pipe is a push fit in the port on the rear of the coolant pump
7.11 Removing the coolant pump assembly (diesel engine)
Page 118 of 225
3*2 Cooling, heating and ventilation systems
12 If tho pump is stuck, tap It gently using a soft-faced mallet • do not lever between the pump and cylinder block mating faces.
Inspection 13 Check the pump body and impeller for signs of excessive corrosion. Turn the impeller, and check for stiffness due to corrosion, or roughness due to excessive end play. 14 Check the clearance between the pump Impeller and the casing using a feeler blade (see Illustration). If the clearance is different to that given In the Specifications, the pump must be renewed. No spare components are available; the pump can only be renewed as a complete assembly. 15 On diesel engine models, remove the O-rlng at the end ol the transfer pipe, which runs behind Ihe cylinder block and fits Into the rear of the coolant pump. A new O-rlng should be fitted as a matter of course.
Refitting
Petrol engine models 16 Commence refitting by thoroughly cleaning all traces of sealant from the mating faces of the pump and cylinder block/pump housing. 17 Apply a continuous bead of sealant {liquid gasket) to the cylinder block mating face of the pump, taking care not to apply excessive sealant, which may enter the pump itself (see Illustration). 18 Place the pump In position In Its housing, then refit and lighten the bolts/nuts to the specified torque. 19 Refit the liming belt as described In Chapter 2A or 28. 20 Refit the auxiliary drivebeltfs) and refill the cooling system as described in Chapter
t
A. 21 Reconnect Ihe battery negative terminal. Diesel engine models 22 Commence refitting by thoroughly cleaning all traces of old gasket from the mating faces of the pump housing and cylinder block. 23 Place a new gasket in position on (he cylinder block, locate the pump in position, then refit and tighten the bolts (see
7.17 On petrol engine models, apply a continuous bead of sealant (liquid gasket) to the pump mating face
pump Impeller and the casing using a feeler blode (diesel engine) illustration). Ensure that the end of the coolant transfer pipe seats firmly In tho port at the rear of the coolant pump, without displacing the O-ring seal. 24 Refit Ihe pump pulley, then refit the securing bolts and tighten to the specified torque. Counterhofd the pulley using the same method employed during removal. 25 Where applicable, refit the power steering pump with reference to Chapter 10. 26 Refit and tension the auxiliary drivebelt(s) as described in Chapter 18. 27 Refill (he cooling system as desenbed in Chapter 1B. 28 Reconnect the battery negative terminal.
8 Heater/ventilation components - § removal and refitting
Complete heater assembly
A
Warning: On mode's fitted with air conditioning, do not attempt to remove the cooling unit, which Is located between the heater blower motor casing and the main heater assembly. Romovat of the cooling unit entails disconnection of refrigerant lines - refer to Section 10 for precautions to be observed.
rfJS
8.3 Slacken the clips (arrowed) and detach the heater unit coolant hoses from the ports at the bulkhead
Page 123 of 225
4A*2 Fuel system - single-point petrol Injection models
2.4a Disconnect the large breather hose... ziecessary when handling it cannot be mrstressed. Note that residual pressure
wttf
remain in the tuei lines long after the wh/cte was last used, When disconnecting any fuel line, first depressurise the fuel
system
(see Section 8).
2 Air cleaner and intet system • removal and refitting
1
Accelerator cable -removal, refitting and adjustment l
Removal 1 Remove the air cleaner element as described in Chapter 1A. 2 Disconnect the outer section from the hot
air
tube and the inlet air duct and remove it
from
the engine compartment. 3II necessary remove the inlet air duct. 4 Disconnect Ihe large and small breather
roses
from the inner section of the air cleaner, tftsn unscrew the retaining nuts and lift the section from the throttle body (see lustrations).
5
Recover the sealing ring. Check the ring for condition and renew it if necessary.
6
Wipe clean the inner surfaces of both the merand outer sections of the air cleaner. Refitting 7 Refitting Is a reversal ol removal but renew
tie
element
H
necessary.
3 Inlet air temperature regulator -removal and refitting
Removal t
The
thermostatically-controlled cold air flap cpener is located in the air cleaner outer ttsrig section. To check the unit, disconnect
ire air
inlet duct with the engine cold and use imrrorto check that the flap Is positioned to aJmit only hot air from the shroud on the utaust manifold. Next, warm up the engine
and
check that the flap moves to admit only sett air from the inlet duct. If the unit is faulty fl must be renewed.
2
Remove the air cleaner element as •senbod in Chapter
1
A.
kickdown cable adjustment as described in Chapter 7B before adjusting the accelerator cable • in its rest position the accelerator pedal should have approximately 8.0 mm free travel.
5 Engine management system components -removal and refitting I
2.4b ... and the small breather hose ...
3 Unscrew the retaining screw and remove the regulator from the air cleaner outer section.
Refitting 4 Refitting is a reversal of removal.
Removal 1 Remove the air cleaner and air inlet ducting as desenbed in Section 2. 2 To release the cable from the throttle body, unscrew the outer cable locknuts, then disengage the inner cable from the throttle cam, and release the outer cable from its mounting bracket. 3 Working under the instrument panel inside the vehicle, unhook the cable from the fork at the top of the pedal arm. 4 Release the bulkhead grommet and withdraw the accelerator cable from Inside the engine compartment.
Refitting and adjustment 5 Refitting is a reverse of the removal process, but adjust the cable (by means of the outer cable locknuts) so that there is only a very small amount of free play present at the throttle body end of the inner cable. Have an assistant depress the accelerator pedal, and check that the throttle cam opens fully and returns to the at-rest position, then secureJy tighten the cable locknuts. On Selecta models, check the
Note: Refer to the warning given in Section 1 before proceeding. Throttle body assembly
Removal 1 Remove the air cleaner and air duct as desenbed in Section 2. 2 Disconnect the wiring connectors from the throttle potentiometer, idle control stepper motor, inlet air temperature sensor and the injector wiring loom connector situated on the front of the throttle body. 3 Depressurise the fuel system with reference to Section 8, then release the retaining clips and disconnect the fuel feed and return hoses from the throttle body assembly, if the original Fiat retaining clips are still fitted, cut the clips and discard them; replace them with standard luel hose clips on refitting. 4 Slacken the accelerator cable locknuts, then disengage the inner cable from the throttle cam and froe tho outer cable from its retaining bracket. Position the cable clear of the throttle body. 5 Disconnect the EVAP purge valve hose, and the MAP sensor hose from the rear of the throttle body. 6 Slacken and remove the four bolts securing the throttle body assembly to tho Inlet manifold, then remove the assembly along with its insulating spacer. Refitting 7 Refitting is a reversal of the removal pro-cedure, bearing in mind the following points: a) Examine the insulating spacer for signs of damage, and renew //necessary, b) Ensure that the throttle body, inlet manifold and insulating spacer ma ting surfaces are clean and dry, then fit the throttle body and spacer, and securely tighten the retaining bolts.
2.4c ... then remove the retaining nuts. 2.4d ... and remove the air cleaner inner section
Page 124 of 225
4A*2 Fuel system - single-point petrol Injection models
motor c) Ensure that all hoses are correctly reconnected and, where necessary, that their retaining clips are securely tightened. d) Adjust the accelerator cable as described In Section 4.
Fuel injector Note: If a faulty Injector Is suspected, before condemning the Injector, it is worth vying the effect of one of the proprietary Injector cleaning treatments. Removal 8 Remove the air cleaner and air duct as described In Section 2. 9 Disconnect the wiring then unscrew the mounting screws and remove Ihe Injector from the throttle body. Refitting 10 Refitting is a reversal of removal.
Fuel pressure regulator
Removal 11 Remove Ihe air cleaner and air duel as described In Section 2. 12 Using a marker pen. make alignment marks between the regulator cover end the throttle body, then undo the four retaining
screws. As the screws are loosened, place a rag over the cover to catch any fuel spray which may be released. 13 Lift off the cover, then remove the spring and withdraw the diaphragm, noting Its correct fitted orientation. Remove all traces of dirt, and examine the diaphragm for signs of splitting. If damage Is found, it will be necessary to renew the complete upper throttle body assembly. Refitting 14 Refitting is a reversal of removal ensuring that the diaphragm and cover are fitted the correct way round, and that the retaining screws are securely tightened,
Idle control stepper motor
Removal 15 Disconnect the battery negative terminal (refer to Disconnecting the battery In the Reference Section of this manual), then remove the air cleaner and air duct as described in Section 2. 16 Using a crosshead screwdriver, unscrew the mounting screws and remove the stepper motor from the throttle body. Recover the gaskei (see illustration). 17 Clean the unit and check for damage and wear. Refitting 18 When refitting the unit use a new gasket and make sure that the plunger is inserted correctly using the following procedure. Insert the unit and refit the mounting screws loosely. Reconnect the wiring then switch on the ignition several times so that the unit centralises itself. Finally fully tighten the mounting screws to the specified torque. Note: The mounting screws are covered with a locking agent and must be renewed every time they are removed 19 Leave the battery negative terminal disconnected for about 20 minutes - the injection/ignition ECU will position the Idle control stepper motor correctly the first time the engine is started. Reconnect the battery negative terminal.
Throttle potentiometer
Removal 20 Remove the air cleaner and air duct as described in Section 2. 21 Disconnect the wiring from the throttle potentiometer. 22 Using an Allen key unscrew the mounting screws then withdraw the unit from the throttle body (see Illustration). Note: The mounting screws ere covered with a locking agent and must be renewed every time they are removed. Refitting 23 When refitting the unit make sure that the pin Is correctly engaged, and tighten the mounting screws to the specified torque. 24 If a Rat test Instrument is available, the
operation of the throttle potentiometer can be checked at this stage. Before connecting the wiring first turn Ihe ignition key to position MAR and wait a few seconds, then return the key to the STOP position, Reconnect the wiring and connect the test instrument. Turn the Ignition key to the MAR position and cancel the error that will appear. The throttle position Indicated should be between 0° and 4°. If greater than this, check thai the accelerator cable is correctly adjusted however If the correct reading cannot be obtained renew the unit.
Inlet air temperature sensor
Removal 25 Remove the throtlle body assembly as described earlier In this Section. 28 Extract the plastic pins and remove the press-fit cover from the top of the throttle body. 27 Invert the cover then unscrew the mounting screws and remove the Inlet air temperature sensor from the cover. Refitting 28 Refining Is a reversal of removal.
Manifold absolute pressure (MAP) sensor
Removal 29 The manifold absolute pressure sensor is located on the left-hand side of the bulkhead. 30 Unscrew the mounting screws and remove the sensor from the bulkhead, Disconnect the wiring and vacuum pipe. Refitting 31 Refitting is a reversal of removal, but check the condition of the vacuum pipe and renew it if necessary.
Coolant temperature sensor
Removal 32 The coolant temperature sensor Is located on the left-hand side of the inlet manifold. Drain the cooling system as described In Chapter 1A before removing it. 33 Disconnect the wiring. 34 Unscrew the sensor and remove It from the Inlet manifold. If using a socket take care not to damage Ihe wiring connector on the sensor. Refitting 35 Refitting Is a reversal of removal bui tighten Ihe sensor to the specified torque. Do not exceed the specified torque otherwise the unit may be damaged.
Crankshaft TDC sensor
Removal 36 The crankshaft TDC sensor Is located on the front side of the crankshaft pulley. Firmly apply the handbrake, then jack up the front of the car Bnd support It securely on axle stands (see Jacking end vehicle support). Remove 5.22 Throttle potentiometer mounting screws
Page 125 of 225
Ihe right-hand front roadwheel and the protective plastic cover under the wheelarch. 37 Disconnect the sensor wiring plug on the front of the engine. 38 Detach the sensor from its mounting. Refitting 39 After refitting Ihe sensor use a feeler blade to check that the gap between sensor and the serrated part of the crankshaft pulley Is between 0.5 and 1.S mm. No adjustment is possible and if the gap is incorrect the sensor and pulley should be checked for possible damage.
Electronic control unit (ECU)
Removal Note: 77ie engine management system has a (earning capability which allows the ECU to store details of the engine's running
characteristics
in its memory,
This
memory
will
tie erased by the disconnection of the battery
cables,
with the resuit that the engine may idle
roughly,
or lack performance for a while, until
the
engine's characteristics are re-teamt. 40 The ECU {electronic control unit) is located on the right-hand Inner wing (see illustration). The 3-pin socket by the ECU is for connection of diagnostic test equipment. 41 Disconnect the battery negative terminal (refer to D/sconnecffng the battery in the Reference Section of this manual). 42 Disconnect the ECU wiring connector, then undo the retaining nuts and remove the unit from the bracket In the engine compartment. Refitting 43 Refitting Is a reversal of removal making sure that the wiring connector is securely reconnected. Inertia safety switch
Removal 44 The inertia safety switch is located by the left-hand side passenger seat. First pull back
the
carpet for access. 45 Disconnect the wiring then unbolt the switch. Refitting 48 Refitting is a reversal of removal.
Fuel injection system relays
Removal 47 The fuel injection system relay is located under a plastic cover on the bulkhead. The MAP sensor is also located under the same cover. 48 Two separate relays are incorporated in the single housing; the left-hand relay has a 5 amp fuse and the right-hand relay has a 25 amp fuse. The main purpose of the relays is to supply current to the fuel pump, ignition coils, oxygen sensor. Injectors and EVAP solenoid. The main relay is controlled by the ignition switch.
4A*2 Fuel system - single-point petrol Injection models
6 Fuel pump/fuel gauge sender unit -removal and refitting
Removal Note: Refer to the warning given in Section 1 before proceeding. 1 Disconnect the battery negative terminal (refer to Disconnecting the battery in the Reference Section of this manual). 2 Remove the rear seat as described in Chapter 11. Prise the fuel pump access cover out of the floor panel to gain access to the pump unit. 3 Disconnect the wiring connector. 4 Bearing in mind the warning given in Section t, disconnect the fuel supply and return lines from the pump unit by pressing the tabs (see illustration). Plug the ends of the lines or cover them with adhesive tape. 5 Using a suitable toot, unscrew the large ring nut and carefully withdraw the fuel pump/fuel tank sender unit assembly from the fuel tank, along with its sealing ring. 6 If necessary, the unit can be dismantled and the pump and sender unit separated. If this is the case, carefully note the correct
fitted positions of oil components while dismantling the unit, and use these notes on reassembly to ensure that all items are correctly fitted.
Refitting 7 Refitting is a reversal of the removal procedure using a new sealing ring. Prior to refitting the access cover, reconnect the battery, then start the engine and check the feed and return unions for signs of leakage.
5.40 ECU located on the right-hand inner wing 49 Remove the cover and pull the relay directly from its socket. Refitting 50 Refitting Is a reversal of removal.
7 Fuel tank -removal and refitting
6.4 Press the tabs Indicated to disconnect the fuel supply and return tines
Note: Refer to the warning given in Section 1 before proceeding.
Removal 1 Before removing the fuel tank, all fuel must be drained from the tank. Since a fuel tank drain plug is not provided, it is therefore preferable to carry out the removal operation when the tank is nearly empty. Before proceeding, disconnect the battery negative terminal (refer to Disconnecting the battery In the Reference Section of this manual), and syphon or hand-pump the remaining fuel from the tank. 2 Remove the fuel pump/fuel gauge sender unit as described in Section 6. 3 Chock the front wheels, then jack up the rear of the vehicle and support on axle stands (see Jacking and vehicle support). 4 Loosen the clip and disconnect the filler pipe from the nght-hand side of the fuel tank. 5 Undo the tank flange and strap mounting bolts, then lower the tank out of position until It is possible to access the hose connections on top of the tank. 6 Loosen the clips and disconnect the EVAP purge hose and breather hose from the fuel tank. If necessary, the filler neck can be detached from the body. 7 Check that all hoses and wiring is disconnected, then remove the tank from underneath the vehicle. Refitting 8 Refitting is a reversal of the removal procedure, ensuring all hoses are correctly routed and securely reconnected.
8 Fuel injection system - ^ depressurisation
Note: Refer to the warning given In Section t before proceeding.
A
Warning; The following procedure will merely relievo the pressure in the fuel system • remember that fuel will still be present In the system components and take precautions accor-dingly before disconnecting any of them.