Chapter 1 Routine maintenance and servicing

Fuel system – carburettor engines 4A•1734 Automatic choke (WeberTLD carburettor) - removal,inspection and refitting4Note: Refer to the warning note in Section 1before proceeding. A new carburettor upperbody gasket will be required whenreassembling. On completion, a tachometerwill be required to check the fast-idle speedadjustment.Removal1 Disconnect the battery negative (earth) lead(refer to Chapter 5A, Section 1).2 Remove the air cleaner as described inSection 2.3 To prevent excess coolant loss, clamp thecoolant supply and return hoses to theautomatic choke unit, and ensure that thecooling system is not pressurised (seeChapter 1). Identify then detach both of thecoolant hoses at the automatic chokehousing. Catch any coolant spillage in asuitable container.Warning: DO NOT attempt toremove the expansion tank fillercap, or to disturb any part of thecooling system, while it or theengine is hot, as there is a very great riskof scalding. If the expansion tank filler capmust be removed before the engine andradiator have fully cooled down (eventhough this is not recommended) thepressure in the cooling system must firstbe released. Cover the cap with a thicklayer of cloth, to avoid scalding, and slowlyunscrew the filler cap until a hissing soundcan be heard. When the hissing hasstopped, showing that pressure isreleased, slowly unscrew the filler capfurther until it can be removed; if morehissing sounds are heard, wait until theyhave stopped before unscrewing the capcompletely. At all times, keep well awayfrom the filler opening.4 Detach the fuel pipe and the anti-dieselingsolenoid wiring connector. Any crimped typehose clips must be replaced with a screwclamp type clips during reassembly.5 Unscrew and remove the retaining screws(two conventional, and four Torx type), then liftthe carburettor upper body clear and remove it.6 Note the position of the choke housingalignment marks, then undo the three retainingscrews and remove the choke bi-metal coilunit. Remove the internal heat shield.7 To remove the automatic choke unit, undothe three retaining screws and detach thechoke link from the operating lever (seeillustration).8 Undo the three retaining screws to removethe vacuum diaphragm unit.9 If dismantling the choke mechanism anyfurther, note the component fitment as an aidto reassembly, but do not detach the chokespindle.Inspection10 Clean and inspect all components forwear, damage and/or distortion. Payparticular attention to the condition of thevacuum (pull-down) diaphragm and the chokehousing O-ring. Renew any items that aredefective (or suspect).Refitting11 Reassemble the automatic chokemechanism, making references to the notestaken during dismantling. Note that nolubricants must be used (see illustration).12 Refit the vacuum unit, making reference tothe notes taken during dismantling. Ensurethat the diaphragm is lying flat beforetightening the housing retaining screws.13 Locate the O-ring (ensuring that it iscorrectly seated), then reconnect the chokelink. Refit the automatic choke unit, and securewith the retaining screws. Check and adjustthe choke vacuum pull-down as describedin the previous Section (paragraphs 5 and 6).14 Refit the inner heat shield, ensuring thatthe location peg is securely engaged in itsnotch.15 Refit the automatic choke housing and thebi-metal spring unit as described in theprevious Section (paragraph 9).16 Refit the carburettor upper body, ensuringthat a new gasket is used and that the matingsurfaces are clean. Fit the retaining screws tosecure.17 Reconnect the fuel hose to the carburettor,using new screw type hose clips to secure it.18 Reconnect the anti-dieseling solenoidwiring connector.19 Reconnect the coolant hoses to theautomatic choke unit, then check and ifnecessary top-up the cooling system asdescribed in “Weekly Checks” and Chapter 1.20 Reconnect the battery negative lead, thencheck and adjust the fast-idle speed asdescribed in Section 31.21 Refit the air cleaner (Section 2).35 Carburettor (Weber TLD) -removal and refitting 4Note: Refer to the warning note in Section 1before proceeding. New gaskets will be requiredon refitting and a tachometer and an exhaust gasanalyser will be required on completion.Removal1 Disconnect the battery negative (earth) lead(refer to Chapter 5A, Section 1).2 Remove the air cleaner as described inSection 2.3 Release any pressure remaining in thecooling system (see Chapter 1), and thendetach the two coolant hoses from theautomatic choke unit. Catch any coolantspillage in a suitable container. Identify eachhose for subsequent refitting, then plug theirends or position them as high as possible toprevent coolant leakage.Warning: DO NOT attempt toremove the expansion tank fillercap, or to disturb any part of thecooling system, while it or theengine is hot, as there is a very great risk ofscalding. If the expansion tank filler capmust be removed before the engine andradiator have fully cooled down (eventhough this is not recommended) thepressure in the cooling system must first bereleased. Cover the cap with a thick layer ofcloth, to avoid scalding, and slowly unscrewthe filler cap until a hissing sound can beheard. When the hissing has stopped,showing that pressure is released, slowlyunscrew the filler cap further until it can beremoved; if more hissing sounds are heard,wait until they have stopped beforeunscrewing the cap completely. At all times,keep well away from the filler opening.4 Disconnect the accelerator cable from thelinkage at the carburettor, as described inSection 3.5 Detach the anti-dieseling solenoid wiringconnector.6 Detach the fuel feed hose at the carburettor.4A34.7 Automatic choke assembly(Weber TLD carburettor)A Pull-down diaphragm housingB Securing screwsA Operating link/fast-idlecamB Fast-idle cam return springC Spindle sleeveD Connecting rod and leverassemblyE Pull-down kinkF Actuating leverG Automatic choke housing34.11 Exploded view of the automatic choke linkage (Weber TLD carburettor)1595Ford Fiesta Remake