Rover 214 & 414 Service and Repair Manual - Rover club

3.4 Slacken clamp to disconnect intake
hose from air cleaner assembly metal
intake duct
4 To remove the metal intake duct,
disconnect the vacuum pipe from the air
temperature control valve and slacken the
intake hose retaining clamp (see illustration).
Undo the fastener securing the duct to its
mounting bracket and remove the metal duct,
taking care not to lose the hot air intake
connector hose which connects the duct to
the exhaust manifold shroud.
5 To remove the air intake hose, it will first be
necessary to remove the left-hand headlamp
assembly so as to gain access to the two
retaining screws. Remove the retaining
screws securing the front of the hose to the
body front panel then release the clip securing
the ignition HT lead to the hose. If the metal
intake duct is still in position, slacken the hose
clamp then remove the hose from the engine
compartment.
6 A resonator chamber is fitted to the intake
hose to reduce the amount of induction noise.
To remove the chamber, first remove the
battery and battery tray. Disconnect the intake
hose and release any relevant retaining
clips from the resonator then remove the
resonator from the engine compartment.
Refitting
7 Refitting is the reverse of the removal
procedure. Ensure that the vacuum pipes are
correctly reconnected and are not trapped as
the assembly is refitted, then check that the
assembly sits properly on the carburettor inlet
before tightening the screws securely.
4 Air cleaner air temperature
control system - inspection
and component renewal
2
Inspection
1 The system is controlled by a thermac
switch mounted in the air cleaner assembly.
When the engine is started from cold, the
switch is closed to allow inlet manifold
depression to act on the air temperature
control valve in the intake duct. This raises a
vacuum servo in the valve assembly and
draws a flap valve across the cold air intake,
Fuel and exhaust systems - carburettor engines 4A•3
4.4 Disconnect vacuum pipe from control
valve to check operation of system
components
thus allowing only (warmed) air from around
the exhaust manifold to enter the air cleaner.
2 As the temperature of the exhaust-warmed
air in the air cleaner rises, a bi-metallic strip in
the thermac switch deforms and opens the
switch to shut off the depression in the air
temperature control valve assembly. The flap is
lowered gradually across the hot air intake until,
when the engine is fully warmed-up to normal
operating temperature, only cold air from the
front of the vehicle is entering the air cleaner.
3 To check the system, allow the engine to
cool down completely, then slacken the intake
hose retaining clamp and disconnect the hose
from the metal intake duct. The flap valve in
the duct should be securely seated across the
hot air intake. Start the engine. The flap
should immediately rise to close off the cold
air intake and should then lower steadily as
the engine warms up, until it is eventually
seated across the hot air intake again.
4 To check the thermac switch, disconnect
the vacuum pipe from the control valve
when the engine is running and place a finger
over the pipe end (see illustration). When the
engine is cold, full inlet manifold vacuum
should be present in the pipe. When the
engine is at normal operating temperature,
there should be no vacuum in the pipe.
5 To check the air temperature control valve,
slacken the intake hose retaining clamp and
disconnect the hose from the metal intake
duct. The flap valve should be securely seated
4.11 Disconnecting vacuum pipe from air
temperature control valve - intake hose-tometal
intake duct securing clamp
(arrowed)
1689 Rover 214 & 414 Updated Version 09/97
4.9 Thermac switch is clipped into air
cleaner assembly
across the hot air intake. Disconnect the
vacuum pipe and suck hard at the control
valve stub. The flap should rise to shut off the
cold air intake.
6 If any component is faulty then it must be
renewed.
Thermac switch - renewal
7 Remove the air cleaner assembly.
8 Release the lid retaining clips then remove the
lid and withdraw the air cleaner filter element.
9 Bend up the tags on the switch clip and
remove the clip, then withdraw the switch and
its seal (see illustration).
10 Refitting is the reverse of the removal
procedure. Ensure that the switch mating
surfaces are clean and that the switch and
seal are correctly located before fastening the
clip.
Air temperature control valve -
renewal
11 Disconnect the vacuum pipe from the air
temperature control valve, then slacken the
intake hose retaining clamp and disconnect
the hose from the metal intake duct (see
illustration).
12 Release the two clips securing the air
intake duct to the air cleaner assembly and
undo the fastener securing the duct to its
mounting bracket. Withdraw the duct, taking
care not to lose the hot air intake connector
hose which connects the duct to the manifold
shroud (see illustration).
4.12 Do not lose hot air intake connector
hose when removing air cleaner metal
intake duct
4A