Chapter 1 Routine maintenance and servicing

1595Ford Fiesta Remake4D•6 Fuel system - sequential electronic fuel injection engines14.27 Idle speed control valve wiringmulti-plug (A) and visible mountingbolts (B)25 Refitting is the reverse of the removalprocedure, noting the following points:a) Renew the regulator sealing O-ringwhenever the regulator is disturbed.Lubricate the new O-ring with cleanengine oil on installation.b) Locate the regulator carefully in the fuelrail recess, and tighten the bolts securely.c) On completion, switch the ignition on andoff five times, to activate the fuel pumpand pressurise the system, withoutcranking the engine. Check for signs offuel leaks around all disturbed unions andjoints before attempting to start theengine.Idle speed control valve26 Disconnect the battery negative (earth)lead (refer to Chapter 5A, Section 1).27 Disconnect the valve’s wiring multi-plug(see illustration).28 Unscrew the three retaining bolts, andwithdraw the valve from the inlet manifold.29 Refitting is the reverse of the removalprocedure, noting the following points:a) Clean the mating surfaces carefully, andalways fit a new gasket whenever thevalve is disturbed.b) Once the wiring and battery arereconnected, start the engine and allow itto idle. When it has reached normaloperating temperature, check that the idlespeed is stable, and that no induction (air)leaks are evident. Switch on all electricalloads (headlights, heated rear window,etc), and check that the idle speed is stillsatisfactory.Mass air flow sensor30 Releasing its wire clip, unplug theelectrical connector from the sensor (seeillustration 4.2a).31 Release the two clips and detach thesensor from the air cleaner cover (seeillustrations 4.2b and 4.2c).32 Slacken the clamp securing the sensor tothe air inlet hose, and withdraw the sensor.33 Refitting is the reverse of the removalprocedure. Ensure that the sensor and aircleaner cover are seated correctly andsecurely fastened, so that there are no airleaks.EEC IV engine managementmoduleNote: The module is fragile. Take care not todrop it, or subject it to any other kind ofimpact. Do not subject it to extremes oftemperature, or allow it to get wet. Refer toPart B, Section 14 for illustrations of thefollowing procedure.34 Disconnect the battery negative (earth)lead (refer to Chapter 5A, Section 1).35 Remove the cooling system expansiontank as described in Chapter 3, for access tothe module multi-plug.36 Unscrew and remove the two nutssecuring the module cover in the enginecompartment, then carefully draw the coveraway from its location. Unscrew the modulemulti-plug retaining bolt and disconnectthe multi-plug from the module.37 The aid of an assistant will be required atthis stage, to support and withdraw themodule from inside the passengercompartment as its mounting bracket retainingtags are compressed and released from theengine compartment. Do not allow the moduleto drop into the passenger compartment asirreparable damage is likely to result. Themodule may be separated from its mountingbracket by undoing the securing bolts.38 Refitting is a reversal of the removalprocedure, ensuring that the modulemounting bracket retaining tags are felt tosnap into position. Refit the expansion tank asdescribed in Chapter 3 on completion.Crankshaft position sensor39 Refer to Chapter 5B.Camshaft position sensor40 Where applicable, release the fuel feedand return hoses from their clip. On PTEengines, detach the adjacent engine breatherhose.41 Releasing its wire clip, unplug thesensor’s wiring multi-plug. Remove theretaining screw, and withdraw the sensor fromthe cylinder head; be prepared for slight oilloss (see illustration).42 Refitting is the reverse of the removalprocedure, noting the following points:a) Apply petroleum jelly or clean engine oilto the sensor’s sealing O-ring.b) Locate the sensor fully in the cylinderhead, and wipe off any surplus lubricantbefore securing it.c) Tighten the screw to the specified torquewrench setting.Coolant temperature sensor43 Refer to Chapter 3.Inlet air temperature sensor44 Releasing its clip, unplug the sensor’selectrical connector, then unscrew the sensorfrom the inlet manifold (see illustration).45 Refitting is the reverse of the removalprocedure.Throttle position sensor46 Releasing its wire clip, unplug thesensor’s wiring multi-plug. Remove theretaining screws, and withdraw the unit fromthe throttle housing (see illustration). Do notforce the sensor’s centre to rotate past itsnormal operating sweep; the unit will beseriously damaged.47 Refitting is the reverse of the removalprocedure, noting the following points:a) Ensure that the sensor is correctlyorientated, by locating its centre on the D-shaped throttle shaft (throttle closed), andaligning the sensor body so that the boltspass easily into the throttle housing.14.41 Disconnecting the camshaft positionsensor wiring multi-plug (Zetec engineshown)14.44 Removing the intake air temperaturesensor from the rear of the inlet manifold(Zetec engine shown)14.46 Throttle position sensor mountingscrews (arrowed)