Fuel and exhaust systems 4�116.29 Disconnect vacuum hose, and unscrew bolts (arrowed) to withdraw fuel pressure regulator rings, and intend to re-use the same injectors, remove the old nose seal and O-rings, and discard them. 22 Further testing of the injector(s) is beyond the scope of the home mechanic. If you are in doubt as to the status of any injector(s), it can be tested at a dealer service department. 23 Refitting is the reverse of the removal procedure, noting the following points: (a) Lubricate each nose seal and O-ring with clean engine oil on installation. (b) Locate each injector carefully in the fuel rail recess, ensuring that the locating tab on the injector head fits into the slot provided in the rail. Tighten the bolts to the specified torque. (c) Fit a new seal to each fuel rail nose, and ensure the seals are not displaced as the rail is refitted. Ensure that the fuel rail is settled fully in the manifold before tightening the three bolts evenly and to the torque wrench setting specified. (d) Fasten the fuel feed and return quickrelease couplings as described in Section 3. (e) Ensure that the breather hose, vacuum hose and wiring are routed correctly, and secured on reconnection by any clips or ties provided. (f) On completion, switch the ignition on and off five times, to activate the fuel pump and pressurise the system, without cranking the engine. Check for signs of fuel leaks around all disturbed unions and joints before attempting to start the engine.16.33 Access to idle speed control valve is from underneath vehicle - unplug electrical connector (arrowed) to check valve 26 Disconnect the battery negative (earth) lead - see Chapter 5, Section 1. 27 Remove the plenum chamber (see Section 4). 28 Disconnect the vacuum hose from the regulator. 29 Unscrew the two regulator retaining bolts, place a wad of clean rag to soak up any spilt fuel, and withdraw the regulator (see illustration). 30 Refitting is the reverse of the removal procedure, noting the following points: (a) Renew the regulator sealing O-ring whenever the regulator is disturbed. Lubricate the new O-ring with clean engine oil on installation. (b) Locate the regulator carefully in the fuel rail recess, and tighten the bolts to the specified torque wrench setting. (c) On completion, switch the ignition on and off five times, to activate the fuel pump and pressurise the system, without cranking the engine. Check for signs of fuel leaks around all disturbed unions and joints before attempting to start the engine.16.40 Unscrew bolts (arrowed) to remove idle speed control valve16.43 Location of idle-increase solenoid valve (A) and diode (B) 36 Plug in the valve electrical connector.Renewal37 Disconnect the battery negative (earth) lead - see Chapter 5, Section 1. 38 Raise the front of the vehicle, and support it securely on axle stands. Warning: Do not place any part of your body under a vehicle when it supported only by a jack! 39 Unplug the valve electrical connector. 40 Unscrew the two retaining bolts, and withdraw the valve from the inlet manifold (see illustration). 41 Since the valve individual components are not available separately, and the complete assembly must be renewed if it is thought to be faulty, there is nothing to be lost by attempting to flush out the passages, using carburettor cleaner or similar solvent. This won take much time or effort, and may well cure the fault. 42 Refitting is the reverse of the removal procedure, noting the following points: (a) Clean the mating surfaces carefully, and always fit a new gasket whenever the valve is disturbed. (b) Tighten the bolts evenly and to the specified torque wrench setting. (c) Once the wiring and battery are reconnected, start the engine and allow it to idle. When it has reached normal operating temperature, check that the idle speed is stable, and that no induction (air) leaks are evident. Switch on all electrical loads (headlights, heated rear window, etc), and check that the idle speed is still correct.4Idle speed control valveCheck31 Disconnect the battery negative (earth) lead - see Chapter 5, Section 1. 32 Raise the front of the vehicle, and support it securely on axle stands. Warning: Do not place any part of your body under a vehicle when it supported only by a jack! 33 Unplug the valve electrical connector (see illustration). 34 Connect a 12-volt battery across the valve terminals - positive (+) to terminal 37 (the green/yellow wire) and negative (-) to terminal 21 (the black/yellow). Caution: It is essential that the correct polarity is observed, or the diode incorporated in the valve may be damaged. 35 A distinct click should be heard each time contact is made and broken. If not, measure the resistance between the terminals. If the resistance is as specified, the valve is okay (but there may be a problem with the wiring or the ECU). If the resistance is not as specified, renew the valve (see below).Fuel pressure regulatorCheck24 Refer to the fuel pump/fuel pressure check procedure (see Section 8).Renewal25 Relieve the residual pressure in the fuel system (see Section 2), and equalise tank pressure by removing the fuel filler cap. Warning: This procedure will merely relieve the increased pressure necessary for the engine to run - remember that fuel will still be present in the system components, and take precautions accordingly before disconnecting any of them.
