compressor FIAT PUNTO 1994 176 / 1.G User Guide

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

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

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Warning: Many procedures In this Chapter require the removal of fuel lines and connections, which may result In fuel spillage. Before carrying out any operation on the fuel system, refer to the precautions given In Safety flrstl at the beginning of this manual, and follow them implicitly. Petrol Is a highly dangerous and volatile liquid, and the precautions necessary when handling it cannot be overstressed. Note that residual pressure will remain in the fuel lines long after the vehicle was last used, When disconnecting tny fuel line, first depressurise the fuel system {see Section 9).
2 Air cleaner and inlet system Sk - removal
and
refitting ^
Removal
1242 cc (8-valve) engines 1 Remove the air cleaner element as described In Chapter 1A. 2 Disconnect the outer section from the hot air tube and the Inlet air duct and remove it from the engine compartment. 3 If necessary remove the inlet air duct. 4 Disconnect the large and small breather hoses from the inner section of the air cleaner, then unscrew the retaining nuts and lift the section from the throttle body. 5 Recover the sealing ring. Check the nng for condition and renew it it necessary. 6 Wipe clean the inner surfaces of both the Inner and outer sections of the air cleaner,
1242 cc (16-valve) engines 7 Release the hose clip and disconnect the inlet air duct from the resonator (see illustration).
2.7 Release the hose clip and disconnect the inlet air duct from the resonator

Fuel system - diesel models 4C*3
14.6 Nuts securing the exhaust downpipe to the exhaust manifold 14.8 Disconnecting the oil return pipe from tho turbocharger
13 Turbocharger -description and precautions
Description A turbocharger 1$ fitted to TDS, TD and SX models. It increases engine efficiency by raising the pressure In the inlet manifold above atmospheric pressure. Instead of the air simply being sucked Into the cylinders. It Is forced in. Additional fuel is supplied by the injection pump in proportion to the increased air inlet. Energy for the operation of the turbocharger comes from the exhaust gas. The gas flows through a specially-shaped housing (the turbine housing) and In so doing, spins the turbine wheel. The turbine wheel is attached lo a shaft, at the end of which is another vaned wheel known as the compressor wheel, The compressor wheel spins in Its own housing, snd compresses the inlet air on the way to the inlet manifold. Boost pressure (the pressure in the Inlet manifold) is limited by a wastegate, which diverts Ihe exhaust gas away from the turbine wheel In response to a pressure-sensitive actuator. A pressure-operaled switch operates a warning light on the instrument panel in the event of excessive boost pressure developing. The turbo shaft is pressure-lubricated by an oil feed pipe from the main oil gallery The shaft floats on a cushion of oil. A drain pipo returns the oil to the sump.
Precautions The turbocharger operates at extremely high speeds and temperatures. Certain precautions must be observed, to avoid premature failure of the turbo, or injury to the operator. Do not operate the turbo with any of its parts exposed, or with any of ils hoses removed. Foreign objects falling onto the rotating vanes could cause excessive
damage, and (if ejected) personal injury. Do not race the engine immediately after start-up, especially if it Is cold. Give the oil a few seconds lo circulate. Always allow the engine to return to idle speed before switching il off - do not blip the throttle and switch off, as this will leave the turbo spinning without lubrication. Allow the engine to idle lor several minutes before switching off after a high-speed run. Observe the recommended intervals for oil and filter changing, and use a reputable oil of the specified quality. Neglect of oil changing, or use of Inferior oil, can cause carbon formation on the turbo shaft, leading to subsequent failure.
14 Turbocharger -removal and refitting
8 Disconnect the oil return pipe from the turbocharger (see Illustration). 9 Unscrew the bolt securing the mounting bracket to the cyfindar block. 10 Unscrew the mounting nuts and withdraw the turbocharger from the studs in Ihe exhaust manifold. Recover the gasket. II It Is to be refitted, store the turbocharger carefully, and plug its openings to prevent dirt ingress.
Refitting 11 Refitting Is a reversal of removal, bearing in mind the fallowing points: a) if a new turbocharger Is being fitted, change the engine oil and filter. b) Tighten ail nuts and bolts to the specified torque. c) Before starting the engine, prime the turbo lubrication circuit by disconnecting the stop solenoid iead at the injection pump, and cranking the engine on the starter for three ten-second bursts.
Removal 1 Remove the battery as described in Chapter 5A. 2 Unbolt and remove the relay guard and bracket from the left-hand side of Ihe engine. 3 Remove the air cleaner and ducting as descnbed in Section 2. 4 Loosen the clips and remove the air outlet duct between tho turbocharger and inlet manifold. Also disconnect the air inlet duct from the turbocharger. 6 Appty the handbrake, then jack up tho front of the vohicle and support on axle stands (see Jacking and vehicle support). 6 Bend back the locking tabs (if fitted) and unscrew the nuts securing the exhaust downpipe lo the exhaust manifold (see Illustration). Disconnect the downpipe from the exhaust system (refer to Part 4D) end remove it from under the vehicle. Recover tne gasket. 7 Unscrew ihe union nut and disconnect the oil supply pipe from the turbocharger. Recover the copper ring and tape over the end of the pipe 10 prevent dust entry.
15 Turbocharger -examination and renovation l
1 With the turbocharger removed, inspect the housing for cracks or other visible damage. 2 Spin the turbine or the compressor wheel, to verify that the shaft is intact and to feel for excessive shake or roughness. Some play is normal, since in use, the shaft is floating on a film of oil. Check that the wheel vanes are undamaged. 3 The wastegate and actuator are Integral, and cannot be checked or renewed separately. Consul! a Flat dealer or other specialist If it is thought that testing or renewal is necessary. 4 If tho exhaust or induction passages are ail* contaminated, Ihe turbo shaft oil seals have probably failed. 6 No DIY repair of the turbo is possible. A new unit may be available on an exchange basis,

Suspension and steering 10*4
3.2 Release the brake fluid line (and where applicable, the pad wear/ABS sensor wiring) from the strut
3 Front suspension strut -removal, overhaul and refitting *

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Warning: If renewing the Strut damper during overhaul both the left and right hand dampers should be renewed as a pair, to preserve the handling characteristics of the vehicle.
Removal 1 Chock the resr wheels, apply the handbrake, then jack up the fronl of the vehicle and support securely on axle stands (see Jacking and vehicle support). Remove the relevant roadwheel. 2 Release the brake fluid line (and wnere
3.3a Remove the two bolts (arrowed)...
applicable, the pad wear/ABS sensor wiring) from Ihe bracket on the base of the strut (see illustration). 3 Remove the two nuts from Ihe bolts securing the lower end of the strut to the hub carrier, noting that the nuls fit on the rear side of the strut (see illustrations). Withdraw the bolts, and support the hub carrier. Discard the bolts and nuts • new ones should be used on refitting. 4 Have an assistant support the strut from underneath the wheel arch then, working In the engine compartment, unscrew the two bolts and release the two stud clips that secure the strut upper mounting plate to the suspension turret. Do not unscrew the centre damper rod nut yet. Release the lower end ol the strut from the hub carrier, then withdraw the assembly from under the wheel arch.
3.7 Fully unsorew and remove tho damper rod top nut 3.3a Withdraw the washer.
3.3b ... and detach the lower end of the strut from the hub carrier
Overhaul Note: Suitable coil spring compressor fools will be required for this operation, and a
new
damper rod top nut must be used on reassembly. 5 Clamp Ihe lower end of Ihe strut in a vice fitted with jaw protectors - take care to avois deforming the mounting bracket at the lower end of the strut. Remove the protective plastic cap from the top of the strut. 6 Fit suitable spring compressors to the coil spring, and compress Ihe spring sutllciently to enable the upper spring seat to be turned by nand.

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Warning: Ensure that the coil spring Is compressed sufficiently to remove all the tension from
tha
upper spring seat, before attempting to remove the damper rod nut. 7 Fully unscrew and remove the damper rod top nut. Countorhofd the domper rod. using
a
suitable Allen key or hex bit. as tho nut * unscrewed • do not allow the rod to rotate inside the damper (see Illustration). Discard the nut • a new one must be used on reassembly. 8 Withdraw tho washer, bush, upper mounting plate and upper spring seat • make a careful note of the order of assembly (see illustrations). 9 Withdraw the spring, complete with the compressors, thon v/ithdraw the dust cover, bump rubber and Ihe lower spring seat rubber (where fitted) (see illustrations).

Suspension and steering 10*5
3,9s Withdraw the coll spring, complete with the compressors ... 3.9b ... then withdraw the dust cover and bump rubber 3.9c Fully dismantled strut
10 With the strut assembly now dismantled, examine all the components tor wear, damage or deformation. Check the rubber com-ponents for deterioration. Renew any of the components as necessary. 11 Examine tho damper for signs of fluid teakage. Check the damper rod for signs of pitting along its entire length, and check the stjul body for signs of damage. White holding fc
in an
upright position, test the operation of
Ihe
stmt by moving Ihe damper rod through a fut stroke, and then through short strokes of
SO
to 100 mm. In both cases, the resistance Id should be smooth and continuous. If the resistance is jerky, or uneven, or if there is any wsible sign of wear or damage to the strut, renewal is necessary. Note that the damper cannot be renewed independently, and if leakage, damage or corrosion Is evident, the complete strut/damper assembly must be renewed {in which case, the spring, upper mounting components, bushes, and associated components can be transferred to
Ihe
new strut). 12 If any doubt exists about the condition of
Ihe
coil spring, carefully remove the spring compressors, and check the spring for distortion and signs of cracking. Renew the spring if it is damaged or distorted, or if there isany doubt about its condition. a Warning: Coil springs are /j\ classified by their height when '
11
• undor load • this Is indicatod by a
coloured
paint marking on the side of the
coll windings (either green or yellow). All coll springs fitted to tho vehicle must be of the same classification to ensure the correct ride height. 13 Clamp the strut body in a vice, as dunng dismantling, then refit the lower spring seat rubber (where fitted), dust cover and bump rubber. 14 Ensure that the coil spring is compressed sufficiently to enable the upper mounting components to be fitted, then fit the spring over the damper rod. ensuring that the lower end of the spring is correctly located In the recess on the lower spring seat (soe illustration). 15 Refit the upper spring seat and upper mounting plate ensuring that the top end of
the spring is correctly located on the upper spring seat. Note that when the strut is reassembled, the orientation marking on the upper rubber mounting must be positioned in relation to the metal section of the upper mounting plate as shown, to maintain the correct front wheel castor setting (see illustration). 10 Fit the new damper rod top nut together with its washer and bush, then tighten the nut to the specified torque, counterholding the damper rod in a manner similar to that used during dismantling. Note that a suitable crows-foot adapter will be required to tighten the damper rod top nut to the specified torque. 17 Remove the spring compressors. Where applicable, refit the protective plastic cap over the damper rod top nut.
Refitting 18 Manoeuvre the strut assembly into position under the wheel arch, passing the locating stud clip through the holes in the body turret. Note that when the strut is refitted, the orientation marking on the upper mounting plate rubber mounting must be positioned in relation to the vehicle as shown, to maintain the correct front wheel castor setting • refer to illustration 3.15. Fit the upper mounting bolts, and tighten them to the specified torque (see illustration). 19 Engage Ihe lower end of the strut with the
3.14 Ensure that the lower end of the spring is correctly located in the recess (arrowed) on the lower spring seat
3.15 Correct positioning of the suspension strut upper mounting components A Left hand mounting for vehicles with manual steering B Left hand mounting tor vehicles with power-assisted steering C To front of vehicle O Orientation marking 3.18 Fit the strut upper mounting bolts, and tighten them to the specified torque