Chapter 4 Part B: Fuel and exhaust systems - single-point fuel injection models · 2013. 8. 12. · Fuel and exhaust systems - single-point fuel injection models 4B•3 6 To remove

4B•1

Chapter 4 Part B: Fuel and exhaust systems -single-point fuel injection modelsContentsAccelerator cable - removal, refitting and adjustment 4Accelerator pedal - removal and refitting 5Air cleaner air temperature control system - general

information and component renewal 3Air cleaner assembly and intake ducts - removal and refitting 2Air cleaner filter element renewal See Chapter 1Bosch Monopoint system components - removal and refitting . . . . 14Exhaust manifold - removal and refitting 17Exhaust system - general information, removal and refitting 18Exhaust system check See Chapter 1Fuel filter - renewal See Chapter 1Fuel gauge sender unit - removal and refitting 10

Degrees of difficulty

Fuel injection system - depressurisation 8Fuel injection system - testing and adjustment 13Fuel injection systems - general information 7Fuel pump - removal and refitting 9Fuel tank - removal and refitting 11General fuel system checks See Chapter 1General information and precautions 1Idle speed and mixture adjustment See Chapter 1Inlet manifold - removal and refitting 16Magneti Marelli system components - removal and refitting 15Throttle body - removal and refitting 12Unleaded petrol - general information and usage 6

Easy, suitable fornovice with littleexperience

Fairly easy, suitablefor beginner withsome experience

Fairly difficult, suitablefor competent DIYmechanic

Difficult, suitable forexperienced DIYmechanic

Very difficult,suitable for expert DIYor professional

SpecificationsSystem type1124 cc (H1A engine) models Bosch Monopoint A2.21360 cc (KDY engine) models Bosch Monopoint A2.21360 cc (KDX engine) models Bosch Monopoint MA3.0Early 1580 cc (B4A engine) models Magneti Marelli G5.S2Later 1580 cc (B4A engine) models Magneti Marelli G6.121580 cc (BDY engine) models Magneti Marelli G6.10Note: Refer to the relevant part of Chapter 2 for further information on engine code identification

Fuel system dataFuel pump type Electric, immersed in tankFuel pump regulated constant pressure:

Bosch system 1.0 barMagneti Marelli system 0.8 ± 0.1 bar

Specified idle speed (not adjustable) 850 ± 50 rpm (controlled by ECU)Idle mixture CO content:

Bosch system (not adjustable) Less than 1.0 % (controlled by ECU)Magneti Marelli system*:

1580 cc (B4A engine) models 1.0 to 2.0 %1580 cc (BDY engine) models Less than 1.0 % (controlled by ECU)

*On the Magneti Marelli system, idle mixture adjustment is possible, but only using special electronic equipment - see text

Recommended fuelMinimum octane rating:

1580 cc (B4A engine) models 95 RON unleaded (UK unleaded premium) or97 RON leaded (UK "4-star")

1580 cc (BDY engine) models, and all 1124 cc and 1360 cc models . 95 RON unleaded (UK unleaded premium).Leaded fuel must not be used

4B•2 Fuel and exhaust systems - single-point fuel injection models

Torque wrench settings Nm lbf ftInlet manifold nuts:

1124 cc and 1360 cc models 8 61580 cc models 22 16

Exhaust manifold nuts:1124 cc and 1360 cc models 16 121580 cc models 22 16

Exhaust system fasteners:1124 cc and 1360 cc models:

Front pipe-to-manifold nuts 30 22Front pipe mounting bolt 35 26Front pipe-to-intermediate pipe nuts 10 7Clamping ring nuts 20 15

1580 cc models:Front pipe-to-manifold nuts 10 7Clamping ring nuts 20 15

The fuel system consists of a fuel tank(which is mounted under the rear of the car,with an electric fuel pump immersed in it), afuel filter, fuel feed and return lines, and thethrottle body assembly (which incorporatesthe single fuel injector and the fuel pressureregulator). In addition, there is an ElectronicControl Unit (ECU) and various sensors,electrical components and related wiring. Theair cleaner contains a disposable paper filterelement, and incorporates a flap valve airtemperature control system. This allows coldair from the outside of the car and warm airfrom around the exhaust manifold to enter theair cleaner in the correct proportions.

Refer to Section 7 for further information onthe operation of each fuel injection system,and to Section 18 for information on theexhaust system.

Throughout this Section, it is occasionallynecessary to identify vehicles by their enginecodes rather than by engine capacity. Refer tothe relevant Part of Chapter 2 for furtherinformation on engine code identification.

Warning: Many of the proceduresin this Chapter require theremoval of fuel lines andconnections, which may result in

some fuel spillage. Before carrying out any

operation on the fuel system, refer to theprecautions given in "Safety first!" at thebeginning of this manual, and follow themimplicitly. Petrol is a highly-dangerous andvolatile liquid, and the precautionsnecessary when handling it cannot beoverstressed.

Note: Residual pressure will remain in thefuel lines long after the vehicle was last used.When disconnecting any fuel line, firstdepressurise the fuel system as described inSection 8.

1124 cc and 1360 cc models1 Refer to Chapter 4A, Section 2, substituting"throttle body" for all references to thecarburettor.

1580 cc modelsRemoval2 Slacken the retaining clip, and disconnectthe air cleaner housing-to-throttle body ductfrom the front of the air cleaner housing.3 Slacken the retaining clip, and disconnectthe air cleaner air temperature control valveassembly from the end of the air cleanerhousing.4 Free the air cleaner housing retaining strap

from its retaining clip, then lift the air cleanerhousing away from its mounting bracket. Ifnecessary, the mounting bracket can then beunbolted and removed from the enginecompartment (see illustrations).5 To remove the intake duct, first disconnectthe vacuum hose from the air temperaturecontrol valve diaphragm. If not already done,slacken the retaining clip securing the controlvalve to the air cleaner housing. Undo thenut(s) securing the front of the duct to thevehicle body, then release the fastenersecuring the rear of the duct in position.Disconnect the hot-air intake hose from themanifold shroud, and remove the duct andhose assembly from the engine compartment(see illustration).

2.4a On 1580 cc models, release therubber retaining strap . . .

2.4b . . . and lift the air cleaner housing outof the engine compartment

2.4c Air cleaner mounting bracketretaining bolts (arrowed) -1580 cc models

2.5 Removing the intake duct and hoseassembly -1580 cc models

1 General information andprecautions

2 Air cleaner assembly and intakeducts - removal and refitting

Fuel and exhaust systems - single-point fuel injection models 4B•3

6 To remove the air cleaner housing-to-throttle body duct, disconnect the breatherhose from the side of the duct, thendisconnect the vacuum hoses from the airtemperature control system vacuum valve,noting their correct fitted positions. Slackenthe retaining clip securing the duct to the aircleaner housing, then slacken and remove thetwo nuts and washers securing the duct to thethrottle body. Remove the duct from enginecompartment. On early models, it will benecessary to disconnect the auxiliary air valvehose from the duct, and to recover the rubbersealing ring from the top of the throttle body(see illustrations).

Refitting

7 Refitting is a reversal of the removalprocedure, ensuring that all hoses areproperly reconnected, and that all ducts arecorrectly seated and securely held by theirretaining clips.

1124 cc and 1360 cc models1 Refer to Chapter 4A, Section 3, substituting"throttle body" for all references to thecarburettor.

1580 cc modelsGeneral information2 Refer to Chapter 4A, Section 3, substituting"throttle body" for all references to thecarburettor.

Vacuum switch - renewal3 Remove the air cleaner-to-throttle bodyduct as described in paragraph 6 of Section 2.4 Bend up the tangs on the switch retainingclip, then remove the clip and withdraw theswitch from inside the duct.5 On refitting, ensure the switch and ductmating surfaces are clean and dry, andposition the switch on the inside of the duct.Refit the retaining clip, then press the switchfirmly against the duct, securing it in positionby bending down the retaining clip tangs.6 Refit the duct as described in Section 2.

Air temperature control valve -renewal7 Disconnect the vacuum pipe from the airtemperature control valve, then slacken theretaining clips securing the valve to the aircleaner housing, hot-air intake hose, and theintake duct.8 Disconnect the intake duct and hose fromthe control valve, then free the valve from theair cleaner assembly and remove it from thevehicle.9 Refitting is the reverse of the removal

2.6a Undo the two retaining nuts . . .

procedure, noting that the air temperaturecontrol valve assembly can only be renewedas a complete unit.

1 Refer to Chapter 4A, Section 7, substituting"throttle body" for all references to thecarburettor. On automatic transmissionmodels, once the accelerator cable iscorrectly adjusted, check the kickdown cableadjustment as described in Chapter 7B.

Refer to Chapter 4A, Section 8.

Note: The information given in this Chapter iscorrect at the time of writing. If updatedinformation is thought to be required, checkwith a Citroen dealer. If travelling abroad,consult one of the motoring organisations (or asimilar authority) for advice on the fuelavailable.1 The fuel recommended by Citroen is givenin the Specifications Section of this Chapter,followed by the equivalent petrol currently onsale in the UK.2 All Citroen ZX single-point injection modelsare designed to run on fuel with a minimumoctane rating of 95 (RON). All 1124 cc and1360 cc models are equipped with catalyticconverters, and therefore must be run onunleaded fuel only. Under no circumstancesshould leaded (UK "4-star") fuel be used, asthis may damage the catalytic converter. Thisalso applies to later 1580 cc models with acatalytic converter. Early 1580 cc modelswithout a catalytic converter can, however, berun on leaded fuel without modification or riskof damage.3 Super unleaded petrol (98 octane) can alsobe used in all models if wished, though thereis no advantage in doing so.

2.6b . . . then detach the duct from thethrottle body, and recover the sealing ring

Bosch Monopoint A2.2 system -1124 cc and early 1360 cc models1 The Bosch Monopoint A2.2 fuel injectionsystem is fitted to all 1124 cc fuel-injectedmodels, and to early fuel-injected 1360 cc(KDY engine) models. The systemincorporates a closed-loop catalyticconverter and an evaporative emissioncontrol system, and complies with the latestemission control standards. The systemoperates as follows.2 The fuel pump, immersed in the fuel tank,pumps fuel from the fuel tank to the fuelinjector, via a filter mounted underneath therear of the vehicle. Fuel supply pressure iscontrolled by the pressure regulator in thethrottle body assembly. The regulatoroperates by allowing excess fuel to return tothe tank.3 The electrical control system consists of theECU, along with the following sensors.(a) Throttle potentiometer - informs the ECU

of the throttle position, and the rate ofthrottle opening or closing.

(b) Coolant temperature sensor - informs theECU of engine temperature.

(c) Intake air temperature sensor - informsthe ECU of the temperature of the airpassing through the throttle body.

(d) Lambda sensor - informs the ECU of theoxygen content of the exhaust gases(explained in greater detail in Part D ofthis Chapter).

(e) Microswitch (built into idle speed steppermotor) - informs the ECU when thethrottle valve is closed (ie when theaccelerator pedal is released).

(f) Ignition HT coil - ECU monitors the coillow tension (LT) circuit to determine theengine speed.

4 All the above information is analysed by theECU and, based on this, the ECU determinesthe appropriate fuelling requirements for theengine. The ECU controls the fuel injector byvarying its pulse width - the length of time theinjector is held open - to provide a richer or

3 Air cleaner air temperaturecontrol system -general information andcomponent renewal

7 Fuel injection systems - generalinformation

5 Accelerator pedal -removal and refitting

6 Unleaded petrol -general information and usage

4 Accelerator cable - removal,refitting and adjustment


weaker mixture, as appropriate. The mixture isconstantly varied by the ECU, to provide thebest setting for cranking, starting (with either ahot or cold engine), warm-up, idle, cruising,and acceleration.5 The ECU also has full control over theengine idle speed, via a stepper motor whichis fitted to the throttle body. The motorpushrod rests against a cam on the throttlevalve spindle. When the throttle valve isclosed (accelerator pedal released), the ECUuses the motor to vary the opening of thethrottle valve and so control the idle speed.6 The ECU also controls the exhaust andevaporative emission control systems, whichare described in detail in Part D of thisChapter.7 If there is an abnormality in any of thereadings obtained from either the coolanttemperature sensor, the intake airtemperature sensor or the lambda sensor, theECU enters its back-up mode. In this event,the ECU ignores the abnormal sensor signal,and assumes a pre-programmed value whichwill allow the engine to continue running(albeit at reduced efficiency). If the ECU entersthis back-up mode, the warning light on theinstrument panel will come on, and therelevant fault code will be stored in the ECUmemory.8 If the warning light comes on, the vehicleshould be taken to a Citroen dealer at theearliest opportunity. A complete test of theengine management system can then becarried out, using a special electronicdiagnostic test unit which is simply pluggedinto the system's diagnostic connector.

Bosch Monopoint MA3.0 system -later 1360 cc models9 The Bosch Monopoint MA3.0 enginemanagement (fuel injection/ignition) system isfitted to all later 1360 cc models with theKDX engine. The system differs from theearlier A2.2 system in that it is an enginemanagement system, controlling both the fuelinjection system and ignition system, ratherthan purely a fuel injection system. Refer toChapter 5 for information on the ignition sideof the system.10 The fuel injection side of the system isvery similar to the A2.2 system describedabove, the only difference being that a coupleof additional sensors are incorporated into thesystem. A crankshaft sensor is fitted to theengine, to inform the ECU of engine speedand crankshaft position, and a vehicle speedsensor is fitted to the gearbox, to inform theECU of the road speed.11 The crankshaft sensor is needed since theECU also controls the ignition side of thesystem, and cannot use the ignition lowtension (LT) circuit to calculate engine speed.The sensor works in conjunction with areluctor ring fixed to the rear of the flywheel.The reluctor ring originally has a total of sixtyteeth, which are equally-spaced at intervals of

6°. Of these sixty teeth, two adjacent teeth areremoved, to leave a gap of 18°. The ECU usesthis gap to establish where TDC is, andcalculates engine speed from the frequency ofteeth passing the crankshaft sensor.

Magneti Marelli system - 1580 ccmodels12 On 1580 cc models, a Magneti Marelliengine management (fuel injection/ignition)system is fitted. There are three versions ofthe system, all of which differ slightly, butoperate on the same principle. Thedifferences are as follows.13 Early models with the B4A (XU5M 2K)engine are fitted with the G5.S2 system. Thissystem differs from later models in thatlt usesan auxiliary air valve to control the engine idlespeed.14 Later models with the B4A (XU5M 2K or3K) engine are fitted with the G6.12 system.On this system, a stepper motor is fitted to thethrottle body assembly to control the engineidle speed.15 Later models with the BDY engine arefitted with the G6.10 system. This system is adevelopment of the G6.12 system,incorporating a catalytic converter and anevaporative emission control system.16 The fuel injection side of the systemoperates as described in the followingparagraphs. Refer to Chapter 5 for informationon the ignition side of the system.17 The fuel pump, immersed in the fuel tank,pumps fuel from the fuel tank to the fuelinjector, via a filter. Fuel supply pressure iscontrolled by the pressure regulator in thethrottle body assembly. The regulatoroperates by allowing excess fuel to return tothe tank. To reduce emissions and to improvedriveability when the engine is cold, enginecoolant is passed through the manifold andaround the throttle body assembly.18 The electrical control system consists ofthe ECU, along with the following sensors.(a) Manifold absolute pressure (MAP) sensor

- informs the ECU of the load on theengine (expressed in terms of inletmanifold vacuum).

(b) Crankshaft sensor - informs the ECU ofcrankshaft position and engine speed.

(c) Throttle potentiometer - informs the ECUof the throttle position, and the rate ofthrottle opening/closing.

(d) Coolant temperature sensor - informs theECU of engine temperature.

(e) Fuel/air mixture temperature sensor -informs the ECU of the temperature of thefuel/air mixture charge entering thecylinders.

(f) Lambda (oxygen) sensor - informs theECU of the oxygen content of the exhaustgases (explained in greater detail in Part Dof this Chapter).

19 In addition, the ECU senses batteryvoltage (adjusting the injector pulse width tosuit, and using the stepper motor to increase

the idle speed and, therefore, the alternatoroutput if the voltage is too low). Short-circuitprotection and diagnostic capabilities areincorporated into the ECU, and it can bothreceive and transmit information via theengine management circuit diagnosticconnector, thus permitting engine diagnosisand tuning by special diagnostic equipment.20 All the above signals are compared by theECU, using digital techniques, with set valuespre-programmed (mapped) into its memory.Based on this information, the ECU selectsthe response appropriate to those values, andcontrols the ignition HT coil (see Chapter 5),and the fuel injector (varying its pulse width -the length of time the injector is held open - toprovide a richer or weaker mixture, asappropriate). The mixture, idle speed andignition timing are constantly varied by theECU, to provide the best settings for cranking,starting (with either a hot or cold engine),warm-up, idle, cruising, and acceleration.21 On the G5.S2 system, the ECU controlsthe idle speed via an auxiliary air valve. The airvalve is connected to the air intake duct andto the throttle body, downstream of thethrottle valve. When the throttle valve isclosed, the ECU controls the opening of thevalve, which in turn regulates the amount ofair entering the manifold, and so controls theidle speed.22 On the G6.12 and G6.10 systems, theECU regulates the engine idle speed via astepper motor which is fitted to the throttlebody. The motor has a pushrod controlling theopening of an air passage which bypasses thethrottle valve. When the throttle valve isclosed, the ECU controls the movement of themotor pushrod, which regulates the amount ofair which flows through the throttle bodypassage, and so controls the idle speed. Thebypass passage is also used as an additionalair supply during cold starting.23 On the G6.10 system, the ECU alsocontrols the exhaust and evaporativeemission control systems, which aredescribed in detail in Part D of this Chapter.24 If there is an abnormality in any of thereadings obtained from any of enginemanagement circuit sensors, the ECU entersits back-up mode. In this event, the ECUignores the abnormal sensor signal, andassumes a pre-programmed value which willallow the engine to continue running (albeit atreduced efficiency). On entering this back-upmode, the engine management warning lightin the instrument panel will come on,informing the driver of the fault, and therelevant fault code will be stored in the ECUmemory.25 If the warning light comes on, the vehicleshould be taken to a Citroen dealer at theearliest opportunity. A complete test of theengine management system can then becarried out, using a special electronicdiagnostic test unit which is simply pluggedinto the system's diagnostic connector.


Note: Refer to the warning note in Section 1before proceeding.

Warning: The followingprocedure will merely relieve thepressure in the fuel system -remember that fuel will still be

present in the system components, andtake precautions accordingly beforedisconnecting any of them.1 The fuel system referred to in this Section isdefined as the tank-mounted fuel pump, thefuel filter, the fuel injector and the pressureregulator in the injector housing, and themetal pipes and flexible hoses of the fuel linesbetween these components. All these containfuel which will be under pressure while theengine is running, and/or while the ignition isswitched on. The pressure will remain forsome time after the ignition has beenswitched off, and it must be relieved in acontrolled fashion when any of thesecomponents are disturbed for servicing work.2 Disconnect the battery negative terminal.3 Place a suitable container beneath theconnection or union to be disconnected, andhave a large rag ready to soak up anyescaping fuel not being caught by thecontainer.4 Slowly loosen the connection or union nutto avoid a sudden release of pressure, andposition the rag around the connection, tocatch any fuel spray which may be expelled.Once the pressure is released, disconnect thefuel line. Plug the pipe ends, to minimise fuelloss and prevent the entry of dirt into the fuelsystem.


Removal1 Disconnect the battery negative lead.2 For access to the fuel pump, tilt or removethe rear seats as described in Chapter 11.

3 Using a screwdriver, carefully prise theplastic access cover from the floor to exposethe fuel pump. The pump is located under theright-hand cover.4 Disconnect the wiring connector from thefuel pump, and tape the connector to thevehicle body, to prevent it disappearingbehind the tank.5 Mark the hoses for identification purposes,then slacken the feed and return hoseretaining clips. Where the crimped-typeCitroen hose clips are fitted, cut the clips anddiscard them; use standard worm-drive hoseclips on refitting. Disconnect both hoses fromthe top of the pump, and plug the hose ends.6 Noting the alignment marks on the tank,pump cover and the locking ring, unscrew thering and remove it from the tank. This is bestaccomplished by using a screwdriver on theraised ribs of the locking ring. Carefully tapthe screwdriver to turn the ring anti-clockwiseuntil it can be unscrewed by hand.7 Displace the pump .cover, then reach intothe tank and unclip the pump from the tankbase. Lift the fuel pump assembly out of thefuel tank, taking great care not to damage thefilter, or to spill fuel onto the interior of thevehicle. Recover the rubber sealing ring anddiscard it - a new one must be used onrefitting.8 Note that the fuel pump is only available asa complete assembly - no components areavailable separately.Refitting9 Ensure the fuel pump pick-up filter is cleanand free of debris. Fit the new sealing ring tothe top of the fuel tank.10 Carefully manoeuvre the pump assemblyinto the fuel tank, and clip it into position inthe base of the tank.11 Align the mark on the fuel pump coverwith the centre of the three alignment markson the fuel tank, then refit the locking ring.Securely tighten the locking ring, then checkthat the locking ring, pump cover and tankmarks are all correctly aligned.12 Reconnect the feed and return hoses tothe top of the fuel pump, using the marksmade on removal to ensure that they arecorrectly reconnected, and securely tightentheir retaining clips.

13 Reconnect the pump wiring connector.14 Reconnect the battery negative terminal,and start the engine. Check the fuel pumpfeed and return hoses unions for signs ofleakage.15 If all is well, refit the plastic access cover.Tilt or refit the rear seat as described inChapter 11 (as applicable).

10 Fuel gauge sender unit -removal and refitting

Refer to Chapter 4A, Section 5, noting thatthere are no fuel pipe connections to thesender unit.

11 Fuel tank -removal and refitting

Refer to Chapter 4A, Section 6, noting thatit will be necessary to depressurise the fuelsystem as the feed and return hoses aredisconnected (see Section 8). It will also benecessary to disconnect the wiring connectorfrom the fuel pump before lowering the tankout of position.

12 Throttle body -removal and refitting


Removal1 Disconnect the battery negative terminal.2 On 1124 cc and 1360 cc models, removethe air cleaner housing-to-throttle body duct,using the information given in Section 2.3 On 1580 cc models, relieve any pressure inthe cooling system by unscrewing the fillercap. Undo the two nuts securing the intakeduct to the throttle body, and position theduct clear of the body along with its rubbersealing ring. Working quickly to minimisecoolant loss, disconnect the two coolanthoses from the rear of the throttle bodyassembly, and plug the hose ends with asuitable bolt or screw (see illustration).4 Depress the retaining clips and disconnectthe wiring connectors from the throttle

12.3 Throttle body coolant hoses(arrowed) -1580 cc models

12.4a On 1124 cc and 1360 cc models,disconnect the wiring connectors from the 12.4b . . . the idle control stepper motor

throttle potentiometer . . . and the injector wiring loom (arrowed)

8 Fuel injection system -depressurisation

9 Fuel pump -removal and refitting


12.4c Disconnecting the throttlepotentiometer wiring connector - 1580 cc

models (injector wiring connector arrowed)

potentiometer, the idle control stepper motor(where fitted), and the injector wiring loomconnector which is situated on the side of thethrottle body (see illustrations).5 Bearing in mind the information given inSection 8 about depressurising the fuelsystem, release the retaining clips anddisconnect the fuel feed and return hosesfrom the throttle body assembly. If the originalcrimped-type Citroen clips are still fitted, cutthe clips and discard them; use standardworm-drive hose clips on refitting (seeillustration).6 Disconnect the accelerator inner cable fromthe throttle cam, then withdraw the outer

12.6b . . . then free the outer cable from itsbracket, and recover the flat washer and

spring clip (arrowed) - 1360 cc modelshown

12.5 Throttle body fuel feed and returnhose unions (1360 cc model shown)

cable from the mounting bracket, along withits flat washer and spring clip (seeillustrations).7 Disconnect the distributor vacuum hose,idle control auxiliary air valve and/or purgevalve hose from the throttle body (asapplicable) (see illustration).8 Slacken and remove the bolts securing thethrottle body assembly to the inlet manifold,then remove the assembly along with itsgasket and/or insulating spacer (seeillustrations).9 If necessary, with the throttle bodyremoved, undo the retaining screws andseparate the upper and lower sections, notingthe gasket which is fitted between the two.

Refitting10 Refitting is a reverse of the removalprocedure, bearing in mind the followingpoints:(a) Where applicable, ensure the mating

surfaces of the upper and lower throttlebody sections are clean and dry. Fit a newgasket and reassemble the two sections,tightening the retaining screws securely.

(b) Ensure the mating surfaces of themanifold and throttle body are clean anddry, then fit a new gasket. Securelytighten the throttle body retaining bolts.

(c) Ensure all hoses are correctlyreconnected and, where necessary, thattheir retaining clips are securelytightened.

12.6a Disconnect the accelerator innercable from the throttle cam . . .

(d) On completion, adjust the acceleratorcable using the information given inSection 4.

(e) On 1580 cc models, check and, ifnecessary, top-up the cooling system asdescribed in Chapter 1.

Testing1 If a fault appears in the fuel injectionsystem, first ensure that all the system wiringconnectors are securely connected and freeof corrosion. Ensure that the fault is not due topoor maintenance; ie, check that the aircleaner filter element is clean, the spark plugsare in good condition and correctly gapped,the valve clearances are correctly adjusted,the cylinder compression pressures arecorrect, the ignition timing is correct, and thatthe engine breather hoses are clear andundamaged, referring to Chapters 1, 2 and 5for further information.2 If these checks fail to reveal the cause ofthe problem, the vehicle should be taken to asuitably-equipped Citroen dealer for testing. Awiring block connector is incorporated in theengine management circuit, into which aspecial electronic diagnostic tester can beplugged. The connector is located insideeither the engine compartment junction box or

12.7 Disconnecting the purge valve hosefrom the throttle body - 1360 cc model

12.8a Throttle body retaining bolts(arrowed) -1360 cc model

12 8b Throttle bodv retaining bolts/studs (1) and upper body retaining

screws (2) - 1580 cc model

13 Fuel injection system -testing and adjustment


14.3a Undo the injector cap retainingscrew, noting the use of a rag to catch any

fuel spray . . .

the ECU plastic box. The tester will locate thefault quickly and simply, alleviating the needto test all the system components individually,which is a time-consuming operation that alsocarries a risk of damaging the ECU.

Adjustment3 Experienced home mechanics with aconsiderable amount of skill and equipment(including a tachometer and an accuratelycalibrated exhaust gas analyser) may be able tocheck the exhaust CO level and the idle speed.However, if these are found to be in need ofadjustment, the car must be taken to a suitably-equipped Citroen dealer for further testing.4 On the Bosch Monopoint system, noadjustment is possible. Should the idle speedor exhaust gas CO level be incorrect, then afault must be present in the fuel injectionsystem.5 On the Magneti Marelli system, it ispossible to adjust the mixture setting (exhaustgas CO level) and ignition timing. However,adjustments can be made only by re-programming the ECU, using specialdiagnostic equipment connected to thesystem via the diagnostic connector.

14 Bosch Monopoint systemcomponents -removal and refitting

Note: On later 1360 cc models with the MA3.0system, the throttle body is effectively asealed unit, with no components availableseparately. This means that, if any of thethrottle body components (including the idlecontrol stepper motor) become faulty, thecomplete assembly must be renewed.Fuel injectorNote: Refer to the warning note in Section 1before proceeding. If a faulty injector issuspected, before condemning the injector, itis worth trying the effect of one of theproprietary injector-cleaning treatments.

On later 1360 cc models with the MA3.0system, at the time of writing, neither the fuelinjector or its seals are available separately. Ifthe injector is faulty, the complete throttlebody assembly must be renewed. Refer to

14.3b . . . then lift off the cap and withdrawthe injector

your Citroen dealer for the latest information.Although the unit can be dismantled forcleaning, if required, it should not bedisturbed unless absolutely necessary.1 Disconnect the battery negative terminal.2 Remove the air cleaner-to-throttle bodyduct, using the information given in Section 2.3 Undo the injector cap retaining screw, thenlift off the cap and withdraw the injector fromthe housing, noting the sealing ring and O-ring. As the cap screw is slackened and theinjector is withdrawn, place a clean rag overthe injector, to catch any fuel spray which maybe released (see illustrations).4 Refitting is a reversal of the removalprocedure, ensuring that the injector sealingring(s) and injector cap O-ring are in goodcondition. When refitting the injector cap,ensure that the injector pins are correctlyaligned with the cap terminals - the terminalsare marked "+" and "-" for identification (seeillustration).

Fuel pressure regulatorNote: Refer to the warning note in Section 1before proceeding. At the time of writing, thefuel pressure regulator assembly was notavailable separately from the throttle bodyassembly. Refer to a Citroen dealer for thelatest information. Although the unit can bedismantled for cleaning, if required, it shouldnot be disturbed unless absolutely necessary.5 Disconnect the battery negative terminal.6 Remove the air cleaner-to-throttle body

14.4 On refitting, ensure that the capterminals are correctly aligned with the

injector pins (arrowed)

duct, using the information given in Section 2.7 Using a marker pen, make alignment marksbetween the regulator cover and throttlebody, then slacken and remove the coverretaining screws (see illustration). As thescrews are slackened, place a clean rag overthe cover, to catch any fuel spray which maybe released.8 Lift off the cover, then remove the springand withdraw the diaphragm, noting itscorrect fitted orientation. Remove all traces ofdirt, and examine the diaphragm for signs ofsplitting. If damage is found, it will probablybe necessary to renew the throttle bodyassembly.9 Refitting is a reverse of the removalprocedure, ensuring that the diaphragm andcover are fitted the correct way round, and thatthe retaining screws are securely tightened.

Idle control stepper motorNote: On later 1360 cc models with the MA3.0system, at the time of writing, the idle controlstepper motor was not available separately. Ifthe motor is faulty, the complete throttle bodyassembly must be renewed. Refer to yourCitroen dealer for the latest information.10 Disconnect the battery negative terminal.11 Depress the retaining clip, and disconnectthe wiring connector from the idle controlstepper motor.12 Undo the retaining screws, and removethe motor from the front of the throttle body(see illustration).

14.7 Fuel pressure regulator retainingscrews (arrowed)

14.12 Idle control stepper motor retainingscrews (arrowed)


14.15 Intake air temperature sensor(arrowed) is an integral part of the injector

cap

13 Refitting is a reverse of the removalprocedure, ensuring that the motor retainingscrews are securely tightened.

Throttle potentiometer14 The throttle potentiometer is a sealed unit,and under no circumstances should it bedisturbed. For this reason, on some models, itis secured to the throttle body assembly bytamperproof screws. If the throttlepotentiometer is faulty, the complete throttlebody assembly must be renewed - refer toyour Citroen dealer for the latest information.

Intake air temperature sensorNote: Refer to the warning note in Section 1before proceeding. On later 1360 cc modelswith the MA3.0 system, at the time of writing,the intake air temperature sensor was notavailable separately. If the sensor is faulty, thecomplete throttle body assembly must berenewed. Refer to your Citroen dealer for thelatest information.15 The intake air temperature sensor is anintegral part of the throttle body injector cap(see illustration). To remove the cap, firstdisconnect the battery negative terminal, thenremove the air cleaner-to-throttle body duct,using the information given in Section 2.16 Depress the retaining clip, and disconnectthe wiring connector from the front of thethrottle body.

14.18 Circular plastic cover (where fitted)is retained by three nuts

17 Place a clean rag over the injector cap, tocatch any fuel spray which may be released.Undo the injector cap retaining screw, and liftoff the cap along with its O-ring.18 Where necessary, undo the three retainingnuts and remove the circular plastic coverfrom the top of the throttle body (seeillustration).19 Release the injector cap connector fromthe throttle body, and remove the injector capassembly (see illustration).20 Refitting is a reversal of the removalprocedure, ensuring that the injector cap O-ring is in good condition. Take care to ensurethat the cap terminals are correctly alignedwith the injector pin, and securely tighten thecap retaining screw.

Coolant temperature sensor21 Refer to Chapter 3.

Electronic control unit (ECU)22 The ECU is located inside the plastic boxwhich is situated directly in front of thebattery.23 To remove the ECU, first disconnect thebattery.24 Unclip the lid from the box, and slide outthe ECU and mounting plate. Disconnect thewiring connector(s) from the ECU, slackenand remove the bolts securing it to themounting plate, and remove it from thevehicle (see illustrations).

14.19 Injector cap wiring connector is apush fit in the throttle body

25 Refitting is a reverse of the removalprocedure, ensuring that the wiringconnectors are securely reconnected.

Fuel injection system relay unit26 The relay unit is inside the plastic boxwhich is situated directly in front of thebattery.27 To remove the relay unit, first disconnectthe battery.28 Unclip the lid from the box, then unclip therelay unit from the mounting plate, disconnectthe wiring connector and remove it from thevehicle (see illustration).29 Refitting is the reverse of removal,ensuring that the relay unit is securely held inposition by its retaining clip.

Injector resistor30 The injector resistor is inside the plasticbox which is situated directly in front of thebattery.31 To remove the resistor, first disconnectthe battery.32 Unclip the lid from the box, then slide outthe mounting plate and undo the resistorretaining bolt. Disconnect the wiringconnector, and remove the resistor from thevehicle (see illustration).33 Refitting is a reversal of the removalprocedure.

14.24a Slide out the mounting plate . . . 14.24b . . . then undo the retainingbolts (1), disconnect the wiring

connector (2), and remove the ECU

14.28 Removing the fuel injection systemrelay unit


14.32 Injector resistor is mounted on therear of the ECU mounting plate

Crankshaft sensor (MA3.0 system)- later 1360 cc models34 The crankshaft sensor is situated on thefront face of the transmission (clutch) housing.35 To remove the sensor, first disconnect thebattery negative terminal.36 Trace the wiring back from the sensor tothe wiring connector, and disconnect it fromthe main harness.37 Prise out the rubber grommet, then undothe retaining bolt and withdraw the sensorfrom the transmission.38 Refitting is a reverse of the removalprocedure. Ensure that the sensor retainingbolt is securely tightened, and that thegrommet is correctly seated in thetransmission housing.

Vehicle speed sensor (MA3.0system) - later 1360 cc models39 The vehicle speed sensor is an integralpart of the speedometer drive housing. Referto Chapter 7A, Section 6 for removal andrefitting details.

Fuel injectorNote: Refer to the warning note at the start ofthis Section before proceeding. If a faultyinjector is suspected, before condemning theinjector, it is worth trying the effect of one ofthe proprietary injector-cleaning treatments. Ifthis fails, the vehicle should be taken to aCitroen dealer for testing using theappropriate specialist equipment. At the timeof writing, it appears that the fuel injector isnot available separately and, if faulty, thecomplete upper throttle body assembly mustbe renewed. Refer to a Citroen dealer for thelatest information.1 Disconnect the battery negative terminal.2 Slacken and remove the two nuts andwashers securing the intake duct to the

15.3 Disconnecting the injector wiringconnector. Injector retaining clip screw

(arrowed)

throttle body, and move the duct out of theway. Remove the rubber sealing ring from thetop of the throttle body.3 Release the retaining tangs, and disconnectthe injector wiring connector (seeillustration).4 Undo the retaining screw, then remove theretaining clip and lift the injector out of thehousing, noting its sealing ring. As the screwis slackened, place a clean rag over theinjector, to catch any fuel spray which may bereleased.5 Refitting is a reverse of the removalprocedure, ensuring that the injector sealingring is in good condition.

Fuel pressure regulatorNote: Refer to the warning note in Section 1before proceeding. At the time of writing, thefuel pressure regulator assembly was notavailable separately from the throttle bodyassembly. Refer to a Citroen dealer for thelatest information. Although the unit can bedismantled for cleaning, if required, it shouldnot be disturbed unless absolutely necessary.6 Slacken and remove the two nuts andwashers securing the intake duct to thethrottle body, and move the duct out of theway, along with its rubber sealing ring.Disconnect the battery negative terminal.7 Using a marker pen, make alignment marksbetween the regulator cover and throttlebody, then undo the four retaining screws(see illustration). As the screws areslackened, place a clean rag over the cover,to catch any fuel spray which may bereleased.8 Lift off the cover, then remove the springand withdraw the diaphragm, noting itscorrect fitted orientation. Remove all traces ofdirt, and examine the diaphragm for signs ofsplitting. If damage is found, it will apparentlybe necessary to renew the complete upperthrottle body assembly, as described earlier inthis Section.9 Refitting is a reverse of the removalprocedure, ensuring that the diaphragm andcover are fitted the correct way around, andthat the retaining screws are securelytightened.

15.7 Fuel pressure regulator is retained byfour screws (arrowed)

15.15 Disconnecting the stepper motorwiring connector

Idle control auxiliary air valve -G5.S2 system10 The idle control auxiliary air valve issituated directly behind the throttle body,mounted onto the cylinder head.11 To remove the valve, first disconnect thebattery.12 Slacken the retaining clips, anddisconnect the two hoses from the side of thevalve. Mark the hoses to ensure they arecorrectly reconnected on refitting.13 Disconnect the wiring connector, thenundo the two retaining nuts and remove theauxiliary air valve from the enginecompartment.14 Refitting is a reverse of the removalprocedure.

Idle control stepper motor - G6.12and G6.10 systemsNote: At the time of writing, it appears that thestepper motor is not available separately and,if faulty, the complete lower throttle bodyassembly must be renewed as describedearlier in this Section. Refer to your Citroendealer for the latest information.15 To remove the stepper motor, depress theretaining tabs and disconnect the wiringconnector (see illustration). Undo the tworetaining screws, and withdraw the motorfrom the rear of the throttle body assembly.16 Refitting is a reverse of removal.

15 Magneti Marelli systemcomponents -removal and refitting


15.18 Throttle potentiometer is secured tothe throttle body by two screws (arrowed)

Throttle potentiometer17 Disconnect the battery negative terminal,then depress the retaining tabs anddisconnect the wiring connector from thethrottle potentiometer.18 Undo the two retaining screws, andremove the throttle potentiometer from theright-hand side of the throttle body assembly(see illustration).19 Refitting is a reversal of the removalprocedure, ensuring that the throttlepotentiometer tang is correctly engaged withthe throttle spindle.

Fuel/air mixture temperaturesensor20 The fuel/air mixture temperature sensor isscrewed into the right-hand side of the inletmanifold, and is removed as follows (seeillustration).21 To remove the sensor, first disconnect thebattery negative terminal.22 Disconnect the wiring connector, thenunscrew the fuel/air mixture temperaturesensor from the inlet manifold.23 Refitting is a reverse of the removalprocedure, ensuring that the switch issecurely tightened.

Manifold absolute pressure (MAP)sensor24 The MAP sensor is mounted on a bracket

15.20 The fuel/air mixture temperaturesensor (arrowed) is screwed into the right-

hand side of the inlet manifold

situated on the right-hand side of the enginecompartment, next to the alternator.25 To remove the sensor, first disconnect thebattery negative terminal.26 Slacken and remove the three retainingnuts and bolts, then free the MAP sensor fromthe bracket. Disconnect the wiring connectorand vacuum hose, and remove the sensorfrom the engine compartment (seeillustrations).27 Refitting is a reverse of the removalprocedure.

Coolant temperature sensor28 Refer to Chapter 3, Section 6.

Crankshaft sensor29 The crankshaft sensor is fitted to the topof the transmission housing, beside the left-hand end of the cylinder block.30 To remove the sensor, first disconnect thebattery negative terminal.31 Trace the wiring back from the sensor toits wiring connector, then depress theretaining tabs and disconnect it from the mainwiring harness. Release the wiring connectorfrom any relevant retaining clips (seeillustration).32 To gain access to the sensor, it isnecessary to remove the metal plate from thetop of the transmission housing. The plate isretained by one of the engine-to-transmission

15.26a Undo the three retaining bolts .

bolts, and by a second bolt securing the plateto the top of the transmission.33 With the plate removed, undo the boltsecuring the sensor to the transmissionhousing, and remove the sensor from thevehicle.34 Refitting is a reverse of removal, ensuringthat the sensor retaining bolt is securelytightened.

Electronic control unit (ECU)35 Refer to paragraphs 22 to 25 of Sec-tion 14.

Fuel injection system relay unit36 Refer to paragraphs 26 to 29 of Sec-tion 14.

15.26b . . . then release the MAP sensorfrom its mounting bracket, and disconnect

the vacuum hose (1) and wiring connector (2)

15.31 The crankshaft sensor wiringconnector (arrowed) is situated on top of

the transmission housing

Removal1124 cc and 1360 cc models1 Remove the throttle body as described inSection 12.2 Drain the cooling system as described inChapter 1.3 Slacken the retaining clip, and disconnectthe coolant hose(s) from the manifold.4 Slacken the retaining clip, and disconnectthe vacuum servo unit hose from the left-handside of the manifold.5 Make a final check that all the necessaryvacuum/breather hoses have beendisconnected from the manifold.6 Unscrew the six retaining nuts, thenmanoeuvre the manifold away from the headand out of the engine compartment. Note thatthere is no manifold gasket.

1580 cc models7 Remove the throttle body as described inSection 12.8 Drain the cooling system as described inChapter 1.9 Disconnect the wiring connector from thefuel/air mixture temperature sensor, which issituated on the right-hand side of themanifold.

16 Inlet manifold -removal and refitting


16.10 Oil filler/breather retaining nut(arrowed) - 1580 cc models

16.12 Inlet manifold coolant hose andMAP sensor hose (arrowed) -1580 cc

models

(b) Ensure that the manifold and cylinderhead sealing faces are clean and flat, andfit the new manifold gaskets. Tighten themanifold retaining nuts to the specifiedtorque.

(c) Reconnect the front pipe to the manifoldusing the information given in Section 18.

(d) On 1580 cc models, refit the disturbed aircleaner components as described inSection 2.

18 Exhaust system -general information, removaland refitting

10 Undo the nut securing the oilfiller/breather to the side of the manifold, thenrelease the assembly from its retaining stud,and position it clear of the manifold (seeillustration).11 Undo the bolt securing the wiring/hosesupport bracket to the top of the manifold,and position the bracket clear of the manifold.12 Disconnect the coolant hose and the MAPsensor vacuum hose from the front of themanifold (see illustration).13 Undo and remove the six manifoldretaining nuts and washers, and remove themanifold from the engine. Remove the gasketand discard it - a new one should be used onrefitting.

Refitting1124 cc and 1360 cc models14 Refitting is the reverse of the removalprocedure, noting the following points:(a) Ensure that the manifold and cylinder

head mating surfaces are clean and dry,and apply a thin coating of suitablesealing compound to the manifold matingsurface. Refit the manifold, and tighten itsretaining nuts to the specified torque.

(b) Ensure that all relevant hoses arereconnected to their original positions,and are securely held (where necessary)by their retaining clips.

(c) Refit the throttle body as described inSection 12.

(d) On completion, refill the cooling systemas described in Chapter 1.

1580 cc models15 Refitting is a reverse of the removalprocedure, noting the following points:(a) Ensure that the manifold and cylinder

head mating surfaces are clean and dry,and fit a new manifold gasket Refit themanifold, and tighten its retaining nuts tothe specified torque.

(b) Ensure that all relevant hoses arereconnected to their original positions,and are securely held (where necessary)by the retaining clips.

(c) Refit the throttle body as described inSection 12.

(d) On completion, refill the cooling systemas described in Chapter 1.

Removal1124 cc and 1360 cc models1 Refer to Chapter 4A, Section 16, noting thatthe lambda (oxygen) sensor wiring connectorsshould be disconnected. Alternatively, caremust be taken to support the front pipe, toavoid any strain being placed on the sensorwiring.

1580 cc models2 Remove the air cleaner housing andmounting bracket, as described in Section 2.3 Slacken the clip securing the hot-air intakehose to the bottom of the air temperaturecontrol valve, then disconnect the hose fromthe manifold shroud and remove it from theengine compartment.4 Undo the remaining manifold shroudretaining bolts, and remove the shroud.5 Firmly apply the handbrake, then jack upthe front of the vehicle and support it on axlestands.6 Slacken and remove the two nuts securingthe front pipe flange joint to the manifold, andrecover the springs. Remove the bolts, thenfree the front pipe from the manifold, andrecover the wire-mesh sealing ring. Eithersupport the front pipe to avoid placing anystrain on the lambda sensor wiring (wherefitted), or disconnect the wiring connectors.7 Undo the eight retaining nuts securing themanifold to the head. Manoeuvre the manifoldout of the engine compartment, and discardthe manifold gaskets.

Refitting (all models)8 Refitting is the reverse of the removalprocedure, noting the following points:(a) Examine all the exhaust manifold studs for

signs of damage and corrosion; removeall traces of corrosion, and repair orrenew any damaged studs.

General information1 On 1124 cc and 1360 cc models, theexhaust system consists of four sections; thefront pipe, the catalytic converter, theintermediate pipe, and the tailpipe and mainsilencer box. All exhaust sections are joinedby a flanged joint. The front pipe joints aresecured by nuts and bolts, the catalyticconverter joint being of the spring-loaded balltype, to allow for movement in the exhaustsystem. The catalytic converter-to-intermediate pipe joint and the intermediatepipe-to-silencer joint are secured by aclamping ring.2 On 1580 cc models without a catalyticconverter, the exhaust system consists of twosections; the front pipe and intermediatesilencer box, and the tailpipe and mainsilencer box. On 1580 cc models with acatalytic converter, the system consists ofthree sections; the front pipe and catalyticconverter, the intermediate pipe and silencerbox, and the tailpipe and main silencer box.The front pipe-to-manifold joint is of thespring-loaded ball type, to allow formovement in the exhaust system, the otherjoint(s) being secured by a clamping ring.3 The system is suspended throughout itsentire length by rubber mountings.

Removal4 Each exhaust section can be removedindividually, or alternatively, the completesystem can be removed as a unit. Even if onlyone part of the system needs attention, it isoften easier to remove the whole system andseparate the sections on the bench.5 To remove the system or part of thesystem, first jack up the front or rear of thecar, and support it on axle stands.Alternatively, position the car over aninspection pit, or on car ramps.

Front pipe -1124 cc and 1360 ccmodels6 Trace the wiring back from the lambda(oxygen) sensor to its wiring connectors, anddisconnect it from the main wiring harness.7 Undo the nuts securing the front pipeflange joint to the manifold, and the single bolt

17 Exhaust manifold -removal and refitting


18.7a Front pipe-to-manifold retaining 18.7b . . . and front pipe mounting boltnuts (arrowed)... (arrowed) - 1124 cc and 1360 cc models

(viewed from underneath)

18.8 Front pipe-to-catalytic converter joint- 1124 cc and 1360 cc models

securing the front pipe to its mounting bracket(see illustrations). Separate the flange joint,and collect the gasket.8 Slacken and remove the two nuts securingthe front pipe to the catalytic converter, andrecover the spring cups and springs (seeillustration). Remove the bolts, then withdrawthe front pipe from underneath the vehicle,taking care not to damage the lambda sensor,and recover the wire-mesh gasket from thejoint.

Front pipe assembly -1580 cc modelswithout a catalytic converter9 Slacken and remove the two nuts securingthe front pipe to the manifold, and recover thespring cups and springs. Remove the bolts,then release the front pipe from the manifold,and recover the wire-mesh gasket from thejoint.10 Slacken the front pipe-to-tailpipeclamping ring bolts, and disengage the clampfrom the flange joint (see illustration).11 Free the front pipe assembly from itsmounting rubbers, and withdraw it fromunderneath the vehicle.

Front pipe assembly -1580 cc modelswith a catalytic converter12 Trace the wiring back from the lambda(oxygen) sensor to its wiring connectors, anddisconnect it from the main wiring harness.13 Disconnect the front pipe from themanifold and intermediate pipe as described

18.10 Typical exhaust system clampingring

above in paragraphs 9 and 10, then removethe front pipe assembly from underneath thevehicle. Be careful not to drop it - the catalyticconverter is fragile.

Catalytic converter -1124 cc and 1360cc models14 Undo the two nuts securing the front pipeflange joint to the catalytic converter. Recoverthe springs and spring cups, and withdraw thebolts.15 Slacken the catalytic converter-to-intermediate pipe clamping ring bolts, anddisengage the clamp from the flange joint.16 Free the catalytic converter from theintermediate pipe, then withdraw it fromunderneath the vehicle. Be careful not to dropit - it is fragile. Recover the wire-mesh gasketfrom the front pipe joint.

Intermediate pipe -1124 cc and 1360cc models17 Slacken the clamping ring bolts, anddisengage the clamps from both theintermediate pipe flange joints.18 Free the intermediate pipe from itsmounting rubbers, then disengage it first fromthe tailpipe and then from the catalyticconverter. Remove the intermediate pipe fromunderneath the vehicle.

Intermediate pipe -1580 cc modelswith a catalytic converter19 Slacken the clamping ring bolts, and

disengage the clamps from both theintermediate pipe flange joints.20 Free the intermediate pipe from itsmounting rubbers, then disengage it first fromthe tailpipe and then from the front pipe.Remove the intermediate pipe fromunderneath the vehicle.

Tailpipe - all models21 Slacken the intermediate pipe-to-tailpipeclamping ring bolts, and disengage the clampfrom the flange joint.22 Unhook the tailpipe from its mountingrubbers, and remove it from the vehicle.

Complete system - all models23 Using the information given under therelevant sub-heading above, unbolt the frontpipe from the manifold, removing the boltsecuring the front pipe to its mounting bracketand/or disconnecting the lambda sensorwiring (as applicable). Free the system from allits mounting rubbers, and withdraw it fromunder the vehicle.

Heat shield(s) - all models24 The heat shields are secured to theunderside of the body by various nuts andbolts. Each shield can be removed once theappropriate exhaust section has beenremoved. If the shield is being removed togain access to a component located behind it,it may prove sufficient in some cases toremove the retaining nuts and bolts, andsimply lower the shield, without disturbing theexhaust system.

Refitting25 Each section is refitted by reversing theremoval procedure, noting the followingpoints:(a) Ensure that all traces of corrosion have

been removed from the flanges, andrenew all necessary gaskets.

(b) Inspect the rubber mountings for signs ofdamage or deterioration, and renew asnecessary.

(c) Prior to assembling a spring-loaded balltype joint, a smear of high-temperaturegrease should be applied to the jointmating surfaces. Citroen recommend theuse of Gripcott AF G2 grease (availablefrom your Citroen dealer).

(d) On joints which are secured by clampingrings, apply a smear of exhaust systemjointing paste to the joint mating surfaces,to ensure an gas-tight seal. Tighten theclamping ring nuts evenly andprogressively to the specified torque, sothat the clearance between the clamphalves is equal on either side.

(e) Before tightening the exhaust systemfasteners, ensure that all rubbermountings are correctly located, and thatthere is adequate clearance between theexhaust system and vehicle underbody.

Documents

Chapter 4 Part B: Fuel and exhaust systems - single-point fuel injection models · 2013. 8. 12. · Fuel and exhaust systems - single-point fuel injection models 4B•3 6 To remove