Chapter 4 Part B: Fuel/exhaust systems - single-point fuel injection ...

4B•2 Fuel/exhaust systems - single-point fuel injection models1 General information andprecautionsThe 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 Part B, 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 theprocedures in this Chapterrequire the removal of fuel linesand connections, which mayresult in some fuel spillage. Beforecarrying out any operation on the fuelsystem, refer to the precautions given in“Safety first!” at the beginning of thismanual, and follow them implicitly. Petrolis a highly dangerous and volatile liquid,and the precautions necessary whenhandling it cannot be overstressed.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 8.2 Air cleaner assembly andinlet ducts - removal and 2refittingRefer to Chapter 4A, Section 2, substituting“throttle body” for all references to thecarburettor.3 Air cleaner air temperaturecontrol system - information 2and component renewalRefer to Chapter 4A, Section 3, substituting“throttle body” for all references to thecarburettor.4 Accelerator cable - removal,refitting and adjustment 2Note: For automatic transmission modelsrefer to Chapter 7B.Removal and refitting1 Refer to Chapter 4A, Section 7 substituting“throttle body” for all references to thecarburettor. Adjust the cable as describedbelow.Adjustment2 Remove the spring clip from the acceleratorouter cable then, ensuring that the throttlecam is fully against its stop, gently pull thecable out of its grommet until all free play isremoved from the inner cable.3 With the cable held in this position, ensurethat the flat washer is pressed securelyagainst the grommet, then fit the spring clip tothe third outer cable groove visible in front ofthe rubber grommet and washer (seeillustration). This will leave a fair amount offreeplay in the inner cable which is necessaryto ensure correct operation of the idle controlstepper motor (see Section 14).4.3 Adjust the accelerator cable asdescribed in text4 Have an assistant depress the acceleratorpedal and check that the throttle cam opensfully and returns smoothly to its stop.5 Accelerator pedal -removal and refitting 2Refer to Chapter 4A, Section 8.6 Unleaded petrol - generalinformation and usageNote: The information given in this Chapter iscorrect at the time of writing. If updatedinformation is thought to be required, checkwith a Peugeot dealer. If travelling abroad,consult one of the motoring organisations (or asimilar authority) for advice on the fuelavailable.The fuel recommended by Peugeot is givenin the Specifications Section of this Chapter,followed by the equivalent petrol currently onsale in the UK.All Peugeot 405 single-point injectionmodels are designed to run on fuel with aminimum octane rating of 95 (RON). Allmodels 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.Super unleaded petrol (98 octane) can alsobe used in all models if wished, though thereis no advantage in doing so.7 Fuel injection systems -general informationNote: The fuel injection ECU is of the “selflearning”type, meaning that as it operates, italso monitors and stores the settings whichgive optimum engine performance under alloperating conditions. When the battery isdisconnected, these settings are lost and theECU reverts to the base settings programmedinto its memory at the factory. On restarting,this may lead to the engine running/idlingroughly for a short while, until the ECU has relearnedthe optimum settings. This process isbest accomplished by taking the vehicle on aroad test (for approximately 15 minutes),covering all engine speeds and loads,concentrating mainly in the 2500 to 3500 rpmregion.Fenix 1B system1 The Fenix 1B system is an integratedsingle-point fuel injection/ignition system.Using inputs from various sensors, theelectronic control unit computes the optimumfuel injector pulse duration, and ignitionadvance setting, to suit the prevailing engineoperating conditions.2 The electronic control unit receives signalsfrom the following sensors.a) Engine speed/position sensor.b) Manifold absolute pressure (MAP) sensor.c) Inlet air temperature sensor.d) Throttle position sensor.e) Coolant temperature sensor.f) Oxygen sensor.3 The fuel injection unit houses the fuelinjector, the fuel pressure regulator, thethrottle position switch, and the idle speedcontrol valve. The single fuel injector injectsfuel upstream of the throttle valve.4 Idle speed is controlled by the electroniccontrol unit, via the idle speed control valve.5 The oxygen sensor allows the electroniccontrol unit to control the air/fuel mixturewithin very fine limits, to enable the use of acatalytic converter.6 All the information supplied to theelectronic control unit is computed andcompared with pre-set values stored in the