Peugeot 205. Manual - part 29

 

  Главная      Peugeot     Peugeot 205 - Service And Repair Manual Haynes

 

поиск по сайту            

 

 

 

 

 

 

 

 

 

содержание   ..  27  28  29  30   ..

 

 

Peugeot 205. Manual - part 29

 

 

4D

Chapter 4  Part D:
Exhaust and emission control systems

Air inlet heating system components - removal and refitting  . . . . . . 4
Catalytic converter - general information and precautions  . . . . . . . . 7
Crankcase ventilation system components - removal and refitting  . 5
Electro-pneumatic ignition timing retarding system components -

removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Emission control system check . . . . . . . . . . . . . . . . . . . .See Chapter 1
Exhaust manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 3

Exhaust system - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . 2
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Fuel vapour recirculation system components - removal and 

refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

General information  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Fluid leaks and hoses check  . . . . . . . . . . . . . . . . . . . . . .See Chapter 1

4D•1

Contents

Easy, suitable for
novice with little
experience

Fairly easy, suitable
for beginner with
some experience

Fairly difficult,
suitable for competent
DIY mechanic

Difficult, suitable for
experienced  DIY
mechanic

Very difficult,
suitable for expert DIY
or  professional

Degrees of difficulty

5

4

3

2

1

1

General information

Exhaust system

The exhaust system consists of front,
intermediate and rear sections, the number
varying according to model. The system is
suspended from the underbody on rubber
mountings, and bolted to the exhaust
manifold at the front. Flanged joints
incorporating gasket seals or pipe clamps are
used to secure the sections. The front section
downpipe is of twin, or “siamesed” type and is
attached to the manifold by a flanged joint
incorporating compression springs or by a
single spherical joint. On TU series engines, a
ball-and-socket type joint is provided
between the front downpipe and intermediate
pipes, to allow for engine movement.
Later fuel-injected models are equipped
with a catalytic converter as part of the
exhaust emission control system.

Emission control systems

Various systems may be fitted to reduce the
emission of unburned hydrocarbons and
harmful exhaust gases into the atmosphere.
Basically, these systems can be divided as
follows:

a) Air inlet heating system.
b) Crankcase ventilation system.
c) Electro-pneumatic ignition timing

retarding system.

d) Catalytic converter.
e) Fuel vapour recirculation system.

The operation of the systems is described
briefly in the following paragraphs.

Air inlet heating system

This system is fitted to certain carburettor
and all single-point fuel injection models, and
assists the vaporisation of the fuel, providing
more complete combustion of the fuel/air
mixture (see illustration). This is achieved by
controlling the temperature of the air entering
the engine.

The air drawn through the air inlet pipe from
the engine compartment is mixed with hot air
drawn from a shroud around the exhaust
manifold. The proportions of hot and cold air
are controlled by the position of a flap valve,
which in turn is controlled by a wax
thermostat and a vacuum capsule (connected
to the inlet manifold).

1.5  Typical air intake heating system

1 Air cleaner
2 Air ducting

3 Exhaust manifold

hot air duct

4 Flap valve
5 Wax thermostat

a Cold air
b Hot air

Crankcase ventilation system

This system is fitted to all models, and
prevents the gases produced in the crankcase
from being released into the atmosphere, at
the same time preventing a build-up of
pressure in the crankcase (see illustration).
Crankcase gases are drawn into the air inlet
tract, where they are mixed with clean air. The
gases are then burnt with the fuel/air mixture
in the engine, and expelled through the
exhaust.

Electro-pneumatic ignition timing
retarding system

This system is used on models fitted with
the Mono-Jetronic A2.2 fuel injection system,
and reduces the nitrous oxide (NOx) content

in the exhaust gases (see illustration). This is
achieved by reducing the temperature at the
end of the combustion by reducing the
ignition advance at certain engine
temperatures.
10 The engine temperature is measured by a
coolant temperature sensor, and this
information is transmitted to the electronic
control unit, which controls the solenoid valve.
Under certain engine temperature conditions,
the solenoid valve cuts off the vacuum to the
distributor vacuum capsule, therefore
reducing the ignition advance.

Catalytic converter

11 Catalytic converters have been
introduced progressively on all models in the

range, to meet emissions regulations.
12 The catalytic converter is located in the
exhaust system, and operates in conjunction
with an exhaust gas oxygen sensor to reduce
exhaust gas emissions. The catalytic
converter effectively cleans the exhaust gases
by speeding up their decomposition.
13 In order for a catalytic converter to
operate effectively, the air/fuel mixture must
be very accurately controlled, and this is
achieved by measuring the oxygen content of
the exhaust gas. The oxygen sensor transmits
information on the exhaust gas oxygen
content to the electronic control unit, which
adjusts the air/fuel mixture strength
accordingly.

4D•2 Exhaust and emission control systems

1.7  Typical crankcase ventilation system

1 Oil filler cap with oil trap
2 Air filter
3 Throttle valve
4 Inlet manifold
5 Jet
6 Ventilation hose
7 Calibrated jet
8 Sump
9 Camshaft cover

Fuel vapour recirculation system

14 This system has been introduced
progressively on all fuel injection models, and
prevents fuel vapour from the fuel tank from
being ejected into the atmosphere (see
illustration)
.
15 The fuel filler cap is sealed, and the fuel
vapours from the tank pass into a carbon
canister, via a calibrated orifice and a pipe.
The fuel vapour is absorbed by the carbon
filling in the canister.
16 When the engine is running, it draws a
proportion of its inlet air through the carbon
canister, and this air picks up the fuel vapour
contained in the carbon canister.
17 A solenoid valve mounted in the pipe
between the canister and the inlet manifold
prevents the system from operating when the
engine is cold. The solenoid valve is
controlled by the electronic control unit, on
the basis of information received from the
coolant temperature sensor.

2

Exhaust system - removal
and refitting

2

Removal

Details of exhaust system routing and
mounting will vary with model and year, but
the principles of removal and refitting remain
the same (see illustration).

Exhaust and emission control systems  4D•3

4D

1.9  Electro-pneumatic ignition timing

retarding system

1 Coolant temperature sensor
2 Electronic control unit
3 Solenoid valve
4 Distributor vacuum capsule

1.14  Fuel vapour recirculation system

1 Fuel filler cap
2 Charcoal canister

3 Hose
4 Calibrated orifice

5 Hose
6 Solenoid valve

7 Coolant temperature sensor
10 Safety valve

In many cases it will be found easier to
remove the complete system from the car and
then to renew individual sections on the bench.
To remove the complete system, raise and
support the vehicle at a convenient working
height (see “Jacking and vehicle support”).
Apply penetrating oil to the nuts, bolts and
clamps which will have to be undone.
Where applicable, disconnect the oxygen
sensor wiring plug is disconnected before
removing the downpipe.
Unbolt the flanged joint at the union of the
exhaust system with the downpipe or at the
manifold connection. According to model,
unbolt the additional support brackets at the
transmission.
With the aid of an assistant, unhook the
system from its mountings and remove it.
With the system removed, undo the
retaining clamp bolts and separate the various
sections as required.

Refitting

Refitting is a reversal of removal, noting the
following points:

a) Ensure that all traces of corrosion have

been removed from the flanges and
renew all necessary gaskets.

b) Inspect the rubber mountings for signs of

damage or deterioration, and renew as
necessary.

c) When tightening a spring loaded flange

joint, tighten the flange mounting nuts
evenly so that the special springs are
compressed equally; approximately four
threads of the bolt should be visible and
the springs should be compressed to
approximately 22.0 mm.

d) Prior to tightening the exhaust system

fasteners, ensure that all rubber
mountings are correctly located, and that
there is adequate clearance between the
exhaust system and vehicle underbody.

3

Exhaust manifold - removal
and refitting

3

Removal

Disconnect the battery negative lead.
Where applicable, disconnect the hot-air
inlet hose from the manifold shroud and
remove it from the vehicle. Slacken and
remove the three retaining screws, and
remove the shroud from the top of the
exhaust manifold
Firmly apply the handbrake, then jack up
the front of the vehicle and support it on axle
stands (see “Jacking and vehicle support”).
Undo the nuts/bolts securing the front
downpipe to the manifold then, according to
model, remove the bolt securing the pipe to
its mounting bracket. Disconnect the
downpipe from the manifold.
Undo the retaining nuts securing the
manifold to the cylinder head (see illustration).

Manoeuvre the manifold from the engine and
discard the manifold gaskets.

Refitting

Refitting is the reverse of the removal
procedure, noting the following points:

a) Examine all the exhaust manifold studs for

signs of damage and corrosion; remove
all traces of corrosion, and repair or
renew any damaged studs.

b) Ensure that the manifold and cylinder

head sealing faces are clean and flat, and
fit the new manifold gaskets.

c) Reconnect the downpipe to the manifold

using the information given in Section 2.

4D•4 Exhaust and emission control systems

3.5  Exhaust manifold upper retaining nuts

(arrowed)

2.1 Typical exhaust system layout

 

 

 

 

 

 

 

содержание   ..  27  28  29  30   ..