2.4 - Exhaust System, Cooling System, Turbo System [OCR]

7/27/2019 2.4 - Exhaust System, Cooling System, Turbo System [OCR]

1/156

b

9

S RVI M NU L

2:4 Exhaust system cooling

system

tur

system

M 98 86

S


2/156


3/156

22

Technical data

2

Special tools

2

Technical description

252

Exhaust system

254

Exhaust emission control system

26

Radiator and cooling system

262 Water pump

27 Throttle controls

29 Turbo system

,

I


4/156

Production: Technical Publications Saab-Scania Trollhattan Sweden

litlre: b:asi units as wel l as the derived units used

throughout

the

Service Manual are in accordance with the SI system.

As

a supplement to these a number

of

other

units

are specified

within brackets.

The following symbols

for

the

various

units

have been used in

this

issue:

Ib

Ibf

Ibfft

Ibf/in

Also equivalent

to

1mm=

0 039

in

1 N =

0 231bs

1Nm=0 74ft lbs

1 bar = 14 5 PSI

11=1 05qts

in

Ibs

Ibs

ft lbs

PSI

qts US

o

Supplementary

unit

Conversion

factors

1i n

=

25 4mm

11bs=

4 45

N

1

ft lbs

= 1 36 Nm

1PSI =

0 07

bar

1qts

= 0 951

Siunit

mm

kg

N

Nm

m r

/

Saab-Scania

AS

1985


5/156

Turbo system

Exhaust

emission control system

Turbo system

022-1

022-2

Cooling system

022-3

8201

8

Maximum

charging

pressure

1981 USA

ba r psI

0.5 2: 0.05 7.2 2: 0.7

1982 USA

ba r

psI

0.6

2: 0.05

8.6 2: 0.7

1983 USA bar psI

0.65 2: 0.05 9.5 2: 0.7

1984- bar

PSI

0.70

0.05

l0.1

0.7

0.85 2: [J:e 5 . 12.3

;I

0.7

-

1984-

USA

bar

PSI

0.75

2: 0.105

l0.8

2:

0.7

Basic charging

pressure,

APC

-1985 bar PSI

0.30

0.03

4.42:0.4 0.40 2: 0.03 5.H 0.4

-1985

USA

bar

PSI

0.35

2:

0.03

5.0 . ; Q ~ G 1 4

1985 ba r

PSI

0.322: 0.03 4.6 2: 0.4

1986

ba r psI

0.322: 0 .03 9.62:

0.4

Tripping

pressure

fo r pressure switch,

1981 USA

ba r

PSI

Non Turbo

0.7 2: 0.1

l0.1

2: 1.4

Others bar

PSI

0.95 2: 0.05 13.8 2: 0.7

1.10 2: 0.05

16.0 2: 0.7

0

Others USA

ba r

psI

0.95

0.05 13.7

0.7

-

-

Turbo shaft

bearing

mm

in 0.025-0.10

mm

end float 0.0010-0.0039

radial clearance

mm

in

0.075-0.18 mm

0.0030-0.0071

022-1


6/156

Exhaust emission control

system

EGR

system

and delay valve, Sweden

specification

also specifications for

Switzerland and Australia

a s f rom

1983 models

Engine

Model year

Type

Flow through Diameter

of

Delay,

valve, restriction,

s

kg/h lb/h

r nm

in

CM

1981-83

2

1984-

On/off

6 13

4.0 0.1575 2

CA

1984-

On/off

20 44

4.3 0.1693

2

TM

1981-83

2

TA

1981-83

On/off

20 44

4.0 0.1575

1M

1981-83

2

1984-*

2-port

10

22 5.0 0.1969

2

IA 1981-83

2-port

10

22

10.0

0.3937

2

1984-

20 44

5.0

0.1969

2

SM, SAM 1982-

On/off

6 13

4.0 0.1575

20

SA, SAA 1981-83

On/off

20 44

4.0

0.1575

6

1984-

20 44

4.0

0.1575

2

S LM

8202

1985- Prop.

20 44 4.7 0.850

This

t ype o f valve was introduced during th e 1983 model year .

Thermostatic

valve

Opening

temperature

c

oF

of thermostatic valve

43

llO

approx.

EGR

Engine

speed

fast idling

at

which

the v a ~ e should

open

EGR valve fully open at

EGR

valve

opens

at

022-2

r/min

r/min

On/off

approx.

2500

approx.

1900

Two-port

approx. 3500

approx.

2600


7/156

s Brown=2 White=6 Green=20

kg lb/h) Green=6 13 Red=10 22 Blue=20 44

- , ;;:olour

coding

- r. - ------------------------------------

, E GR v al ve :

~ D e l a y

valve:

Mechanical

throttle orhrnper dash pot)

A s f ro m

1983

m od el s, a ls o a pp l ic ab l e to Switzerland sp ecificatio ns

Delay t im e f ro m

3000

r/min -to idling speed

Setting

s p ee d : s in gl e carburetor

twin

carburetors

fuel

injection

Turbo

16

s

r/min

r/min

r/min

r/min

Sweden

3- 6

2600 10 0

3000 10 0

2000

10 0

2600 100

Europe

3- 6

2500

10 0

2600 100

Cooling system

Coolant

Type

Capacity

Sa ab Original Coolant

l i tre

qts) 10 l0.5)

Thermostat

Opening

temperature

Certain

market

specs.

only

Expansion tank

89 2 192 4

82

2 179

P re s su re v al ve opens at

Thermostatic

switch

ba r psI 0. 9 - 1. 2 13-17)

Makes circuit

at

Breaks

circuit

a t

90 - 95 l 9 l ~ - 2 0 3

85 - 90 185-194)

022-3


8/156


9/156

S 5

8392912

8396480

Sealing pliers, charge

pressure regulator,

Turbo, control unit

Socket adaptor for

Turbo oil

return

pipe

8393472

8393 514

Bihex f la re nut socke t

S 2 027

Pressure

gauge

fo r

Turbo APC boost

and

component check

S2026

83 93 548

83 94074

Test wiring harness

up to 1985 models

Tes t wiring harness

as

from 1986

models

102-1


10/156


11/156

Turbo system

APC System

Description of

components

Charging pressure regulator

200 2

200 7

200 10

Description of

APC

components

Knock

detector

Pressure

transducer

Control unit

200 12

200 12

200 13

4

5

\

\

\

\

\

\

/

._ .

3

8 1

1 Turbocharger

2 Waste gate

valve

3

Diaphragm unit

4 Pressure

switch

5 Turbo

gauge

6

Hose

ai r

cleaner

to turbocharger

7

Hose

turbocharger to inlet

manifold

8

Exhaust

pipe

9 Oil supply

line

10 Oil return

line

Turbo engine

9 6

200 1


12/156

Turbo

system

Supercharging, general

In contrast .to conventional engines, a

super-charged eng ine provides improved

charging on the induction stroke,

which

p roduce s mor e effective combustion of

the

mixture and an increase in power

out

pu t and torque. With a supercharged

engine,

it

is possible t o ach ieve

perfor

mance that is comparable

to

that of a

lal\J8 :' 3ngine, while, at the same time,

rnainta:ming the advantages of a smaller

engine

with

respect to fuel

economy,

space, weight,

etc.

Turbocharging

TUI:bocharging is achieved by means

of

a

turbo-compressor,

utilizing

the exhaust

gases

f rom the

engine to drive

the turbine.

The

exhaust

gases

ar e

led to an exhaust

gas

turbine, causing

the

turbine

wheel

to

ro

tate.

The turbine

wheel

is mounted on the

same

shaft as a

compressor

impeller which

rotates

at

the

same speed.

The compressor is located in the induct ion

s ystem whe re it

effects

an increase in the

charging

pressure in the

combustion

cham

ber.

200-2

The Saab

Turbo

unit has be en

designed

to

start opera ting at relatively low engine

speeds,

in

ord er to

provide

increased

tor

que at engine

speeds typ ical

of

normal

driving condi

tions.

In

contrast

to t he Saab

Turbo,

earlier turbochargers

have

been

de

s ign ed to

provide

increased performance,

which implies

that

they are

only

utilized

at

full throttle.

The

turbine

shaft

which

rotates

at er

high speed has been

very

accuralely oal

anced.

The

shaft

is.

mounted

in a floating

sliding-contact

bearing

through which

there is a relatively high oil flow. Thus,

during

rotation,

the shaft floats on a film

of oil.

The lubricating oil is

supplied

by

the

engine

lub ri ca ti ng sys tem through

a

special

line

running from the oil pump. Return oil flows

through a

relatively

large-bore pipe back

to

the sump.

Sealing

between the shaft and

the bearing

housing c onsists of sea ling

rings

piston

ring

type installed in grooves in the

shaft.


13/156

c

Turbo compressor sectIOn

Exhaust gases

Inlet

ai r

Turbine housing

Bearing housing

3 Compressor housing

4

Radial bearing

5 Axial

bearing

6

Turbo

shaft

7 Turbine wheel

8 Compressor impeller

A From

exhaust manifold

B To exhaust pipe

C From air c leaner

o To inlet

manifold

E

Lubricating

oil

line

F Lubricating oil

return

pipe

200 3


14/156

4

Diaphragm unit

Pressure switch

Throttle bytterfly

7

5

6

7

The

specified

maximum charging

pressure must not

be

exceeded as this

resul

ts

in a

very real danger of da

mage to

the

engine.

Caution

When pressure in th e compressor is greater

than

that c

f th e spring the flap

is

opened

thereby relea sing some gases f rom

the

side

or

th e

turbine so

reducing the

load

it

is

subjected to. This in turn also reduces th e

compressor pressure.

The

charging pressure regulator

is a

flap

valve which c lo se s o r opens

the

by-pass

duct

at

the si de of the

turbine

wheel . The

f la p valve is

activated

by a

rod

from a

d iaphragm capsu le situated a t

the com

pressor

housing. A spring in th e diaphragm

capsule

closes the f lap. The d iaphragm is

activated

by pressure in the compressor.

Turbo-compressor

Turbine

wheel

Compressor impeller

Charge

pressure

regulator

Engine idling

1

2

3

Exhaust

gases

Inl e t a ir

200-4

S 9

3

The

charging pressure in

t he inl et

manifold

is principally

controlled

by eng in e s pe ed

and l oa d. The cha rg ing p re ss ur e is howe

ver limited under high

loads

by a charging

pressure regulator.

The cha rg ing

pressure

regulator is located on t he exhaust side of

the

engine

and

controls th e e xh au st

gas

flow

through a by-pass

duct

at the sid e of

the turbine.

Charging pressure

ontro

The

charging pressure

regulator{waste-gate

valve is closed when the load on th e engine

is

normal

or les s. As th e load increases and

the charging pressure approaches

th e maxi

mum

permi ss ib le l ev el

the

waste-gate

opens a ll owing s ome o f t he exhau st

gases

to pass through the by-pass duct t hereby

partially decreasing th e load on th e tur

bine.


15/156

S 9 8

Inle t a ir

Exhaust gases

Full load

Inlet ai r

Exhaust gases

Partial

load

2 5


16/156

98

Inlet ai r

Exhaust

gases

Excessive pressure

in

t he i nl et

manifold at

full load e.g. sticking charging

pressure

regulator

Overpressure relief

system

and over-rev

ving cut-out

overpressure

reUef

system

is

provided

which is

activated

when the charging pres

sure in the

inlet

manifold becomes exces

sive in

order

to prevent over-loading the

engine should

th e

wastegate mal

function.

The

overpressure

relief

sys tem consi st s of

an overpressure switch which is connected

to

the inlet

manifold via a hose. The

over

pressure switch is located under th e

inst

rument panel on the same mounting brac

ket

as th e flasher relay

etc.

At excessive charging pressures th e

over

pressure switch cuts

o ff t he

electric

supply

to the

fuel

pump.

To prevent engine over-revving

the

pump

r el ay has an extra function

t ha t cut s

ou t

the

electric .fuel pump at engine

speeds

above 6 000 r/min.

200-6


17/156

pressure

gauge

on the inst rument panel

shows the

charging

pressure.

The

pressure

gauge is connected by a hose to th e i nle t

manifold via the overpressure switch.

e System

General

Recen t t rends

in the

fuel market

have

meant that the supply of fuel has been

irregular and this has resulted in varying

quality.

The quality of

automobile

fuel

also varies

as a

result of different standards and en

vironmental requirements in

various count

ries which

means

that t he oct ane

rating

can

vary

by several

points

from one

country

to

another.

The e system enables opt imum use

to

be made of the properties of a given fuel in

order to achieve high engine output and

good

fuel economy.

Knocking or pinking occurs when

the en

gine

is put under high load while combust

ing fuel of

an insufficiently

high octane

rating.

In

technical terms

knocking

means

that

th e

fuel

self-ignites which

if

no t

rectified

can caus e

serious

damage

the engine.

In

addition

tt

the knQckinrJ W

lieh can

be

detected under temporary high load condi

tions

there is a knocking associated with

high engine speeds which is impossible fo r

the

ea r

to detect. This type

of

knocking

causes the most

damage.

200-7


18/156

In o rd er to a vo id t hi s type of dam age th e

manufact urers have been

forced

to

incor

porate safety margins

in t he ir e ng in es

to

allow

f or d if fe re n ce s in fuel

quality,

with

th e result

that

it ha s no t b ee n p os si bl e t o

make full use of

th e

energy

obtainable

from

th e

fuel

fo r

propelling

th e ca r

e ne rg y h as b ee n lost in th e form o f w as te d

heat.

Note

A c o nt ro l s y st e m su ch as th e AP C syst em,

based as it is on a knock detector,

ca n

never eliminate individual occurrences

of

knocking as

the se a re

necessary

fo r

th e

function

of the system. T hi s k no ck in g is

no t detrimental

to th e engine.

U nd er n or ma l operation of th e syste m,

with th e e n gi n e u n de r

load,

p e ri o di c k n oc

king

ca n

be heard in

th e p as se nge r c om

partment

- on e

knock

approx. every

three

s ec o nd s . T h is

knocking

is no t

detrimental

to t h e e g in e .

Principle of operation

,The APC system consists of fe w

moving

parts.

Th e

system

is

principally

based

on

simple electronic c om p on en ts w hi ch m ak e

it

relatively

robust

an d

easy

to

service.

An e ng in e w it h th e AP C system

automati

cally a da pt s i ts el f

to the

quality of fuel

being used.

A knock

detector

1)

senses

th e engine s

load

ratio knocking t en de nc y) a nd trans

mits

an electrical

signal t o t he c on tr ol u ni t

3) w hi ch a ls o receives signals from th e

pressure transducer

2)

an d

th e

igni

tion

system en gi n e s pe ed ) .

T he se s ig na ls ar e

processed by t he c on tr ol

unit v:hich trans

mits

elp. ctric impuls es to a so ~ n o vcllve

which in u r ~ g u l t s th e diaphragm

unit.

200-8


19/156

Through continual a dju stmen t o f th e c ha r

ging pressure to s ui t t he

octane

rating and

the

engine

working

conditions,

the margins

which are

normally

built into the

engine

in

order to avoid damage may be circumven

ted. This allows opt imum uti lizat ion of

th e

f ue l b ei ng u sed,

i.e.

the

max.

possible en

gine output is

a lways avail ab le for p ropu l

sion

Electrical

signal from

the

engine

ignition

system

engine rpm

The APC system senses and control s the

charging

p re ss ur e of th e engine.by means

of

an electric

pressure

transducer.

This

pressure transducer also compensates for

changes in the condition

of

the engine. The

maximum charging-pressure

setting

should

therefore

no t be

altered.

S 2 058

APC-system

Electrical wiring

I J

Air

hose

2

3

4

Knock detector

Pressure transducer

Control uni t

Solenoid valve

200-9


20/156

Description of com ponents

Charging pressure

regulator

Charging pressure

regulator

housing

1

Charging pressure

regulator/

2

By-pass passage

3 Flap valve

Diaphragm unit

5

Lever

Control arm

7 Anti-tamper

seal

The charg ing pressure

regulator

housing

is

bol ted d ir ect ly onto the turbocharger hou

sing.

The

d iaph ragm uni t

is

mounted

01 )

compressor

housing

with

bracket an\ is

connected

by a

lever to the regulator con

t ro l a rm.

The end of

the lever is

adjustable

so

enabling

the

tension

on

the diaphragm

uni t spr ing

to be altered. The end of the

lever

is

s ecur ed t o

a

stud

on

t he con trol

arm

by a

circlip

and an

anti-tamper

seal

is

f it te d t o prevent unauthorized adjustment.

200-10

/


21/156

Description of e components

Knock

detector

Pressure transducer

as

from

983 mo

dels, l oc at ed benea th t he i ns tr umen t

panel

3 Control uni t under rear seat cushion;

as from 986 models: on LH side in

engine

compartment

4 Solenoid

valve

Location of control unit, -1985 Location of control unit as from

986

models

200-11


22/156

Knock detector

The knock detector 1 registers any

knock-

ing/pinking in the

engine

and converts it to

electric

signals

that are transmit ted

to

the

control unit 3 .

The knock detector also starts up th e APC

system

when

i t r eg is te rs t he

normal

vibra-

t ions of

the

engine.

knock detector is mounted on

the

left

side

of

the

engine

below he inlet

manifold.

Pressure transducer

The

pressure transducer 2

registers

the

pressure downstream

o f th e

throttle.

The pressure is

converted

to an electric

s ignal which

is

transmitted

to

t he con trol

unit

3 .

The pressure transducer ensures

that the maximum boost

supplied

to the

engine is correct

even

i f t he per fo rmance

of

other

engine

parts

changes

during

the

l if e o f th e

engine.

The pressure

transducer is mounted

at

the

top of

th e

left wheel housing up

to

and

incl. 1982 models .

200 12


23/156

As

from

1983

models,

the

pressure trans

ducer is

located

under

th e in str umen t

panel.

Control

unit

The control

unit 3

receives

electric sig

nals

from th e knock detector 1 , t he pres

sure t ransducer 2 and

th e

ignition

system

engine

spee d , ana lyse s t hem

and

then

activates

th e

solenoid valve

4 .

The

control unit is

mounted under

the rear

seat

cushion up to and incl. 1985 models .

As

from

1936

models,

t he control

unit

is

mounted on

th e

LH wheel

arch

inside the

engine

compartment.

The

unit is hose

proof,

has a new

25-pin

connector

and a lso

incorporates

a

new function:

on

braking,

the APe system automatically reduces the

charging

pressure to the basic setting.

, .

200-13


24/156

Solenoid

valve

= J connection

R

f rom con trol uni t 3

Solenoid valve 4

)(

connection

l i i l ~ ] r ~ ; ~ ~ ~ ~ ~ Exhaust gases S 2/060

t ~ ~ ~ ~ Inlet air before turbocharger

2;4 };;; Inlet a ir after turbocharger

connection

I

W

I

With

the

solenoid

valve

fully

open

the

pressure througt:t connection R of

the

solenoid valve is vented via a

hose

connected

to

the inlet

side of

the

compressor. The

orifice

in connection

C is so small in relation to

the

solenoid valve

discharge area that the

small ai r flow that passes

through

the

sol enoid loses a ll

it s

pressure through

the orif ice.

With

the

sol enoid valve completely

shut

th e

charging pressure regulator

val ve is

exposed

to the full pressure of

the

inlet

manifold

as there is no flow

through the

solenoid valve

connection

to produce a pressure drop.

The

regu

lator

valve

then

opens

and provides a

low

charging

pressure

as

determined

by

it s

basic setting.

The

regulator

valve loses

it s pressure

and

thus closes

so

increasing the

boost.

200-14

The

current

pulse ratio

is

regulated

by

the

control unit

(3).

The solenoid valve

is

fed

with the pressure

that exists in

the

inlet

manifold

after the

compressor. There is an

orifice

of fixed

diameter

mouflte d in the

solenoid

inlet.

The solenoid valve (4)

regulates the control

pressure

to

the charging pressure regulator

valve

which in tu rn d ete rm in es t he c ha r

ging pressure.

The charging pressure

regulator

valve is

connected downstream

of

th e

ori ficso The

mean out le t a re a of

the

solenoid valve is

determined

by

the

pulse

ratio

of current

fed

to

th e

solenoid i.e.

the

pulse relation

ship

between the

open and closed valve.


25/156

i

When

the

ca r is

running, the

solenoid

valve

oscillates

between the open and

closed posit ions at a

fixed

frequency

t 12 Hz.

When the

char2ing

pressure

exceeds 0.4 ba r

Ib/in

), th e pulse

wid th changes . The pulse width is the

ratio between the time the

valve

is

open and

the t ime i t

is closed d ur in g a

cycle of 1/12 th of

a

second. The pulse

width

is determined by the c o n t r o ~

unit,

on th e

basis

of signals received

by th e control unit

from

the kn ock

detector 1), th e pressure transducer

2) and

the

ignition

system

engine

speed .

The

solenoid

valve is mounted on t he r igh t

of th e upper

part of

th e

radiator member.

To

the

charge

pressure

regulator

diap,h,ragm unit

6 { L

'FI / IA

/O: -VJ 1 )\1 { f i

o/I-e \

J

~ ~ , ( 1 J ~

lfm:

- ~ n l e ~

air

upsdearn ::l

, . - . l ~ of t l J t ~ o c h a r g e r

{

I

l l l . C . ' w l I . v : I 1 ~ ( . l ' h c ' ~

Ifllet

ai r

downstream

of EurboGhprger

t

/ ~ , , , , & v

200-15

Wiring

runs and

location of components


26/156

Control unit

as

from

986 models

\ -

Pressure transducer

as

from 1983

models

Ignition

pulses

from

fuel pump

relay to

control unit up

to

an. incl. 985

mod elG

Cable harness wheel housing

200 16

Knock detector connector

up to and

incl.

98 models


27/156

Exhaust

man ifo ld o v erv iew

Exhaust

manifold:

carburettor and

injection engines 8201

Exhaust manifold:

Tu rb o en gin e 8 2 0 1

Exhaust

manifold:

Tu rb o en gin e 8 2 0 2

E haust

manifold:

in jectio n en gin e 8 2 0 2

252-1

252-2

252-3

252-4

252-5

Exhaus t s ystem overview

Heat shields

General d e sc r ip ti o n o f f it t in g o f

exhaus t s ystem

Exhaust system:

Tu rb o en g in es

252-6

252-8

252-9

252-12

Exhaust manifold - overview

General

Ex h au st manifold s

ar e

either in the for m o f

a casting or

made

from sheet according to

th e

engine

variant

to which they

ar e fitted.

Th e

exhaust

manifold is secured to th e

cylinder head by meanG, of studs and nuts;

d is ta nc e p ie ce s a re interposed t o p r es tr e ss

th e

f la ng e j oi nt

to

a ll ow n ec es sa ry m ov e

ment

of

th e

manifold on t he rm al e xp an

sion.

s

To

prevent

t e ns io n a ri s in g f ro m c h an g es in

length

th e

stud

holes

in th e manifold

flanges ar e oversized

to

provide

clearance

around

th e

s tuds . T he nut s m us t a lways be

tightened to the

specified torque on

fit

ting.

T he s eal

b et we en t he

m an if ol d f la ng e a nd

th e cylinder-head flange

face

is provided

by a

gasket

which a lso serves

as

a heat

shi el d. Addit iona l g as ke ts a re

used

to

offset

a ny d i st o rt i on in

th e

mating

surfaces

of

th e

manifold.

These

additional

gaskets

r i

fitted b et we en t he

e x ha u st m a ni fo l d

an d

t h e h e at - sh ie l d g a sk et .

252-1


28/156

Exhaus t manifold: B201

carburettor &

in-

jection engines

remove

1. D i s [ ~ m n e c t the'.

r ~ r e g p t i i e

:.)

battery

lead.

2.

Remove

the

gear.box,...oil. filler .

tube an d

plug

th e Hl mle

(mal'lual

gearbox

only).

3. Puslh, asi .ml :l tim-e pne.rn-e.aten hose an d re

m ~ ~ e tfue fjlreheatrerr co.v.e.r,.;,

4.

tJ:l bm:tt

the;

exf l ugjt p,ip:e from the ex

haus'tl: manj;1

T

m1Jd.,

5.

Slightly naIse; htrrre taiL

end

of

th e en

gine.

6.

Unbolt th e engine

bracket

from the

cylinder

head

and

en gin e mo u ntin g.

7. Remove th e

intermediate

manifold

section (N A to sheet-steel manifolds

as

t h es e a r e o f i n te gr al c o ns tr u ct io n .

8.

Rel1Til i)ve

the ou ter exhaust manifold

and' tttiTe gasket.

o

t

Fit.

ur

th e l ev.:erse

order.

252-2

Two-piece exhaus t-manifold casting fitted

t o 8 20 1 carburettor and injection

engines

Integral

sheet-steel exhaust

manifold

fit

te d to 82 01 carburettor and

i nj ec ti on e n

g in es a s from 1986 m od el s w i th Sa n d EU

specs

Gaskets

Exhaus t-manifold casting

fitted

to

8 2 0 l

carburettor

and i nj ec tion engines wit h

catalytic

converter emission control


29/156

Exhaust manifold:

6201

Turbo engines

To remove

1.

Raise the

ca r

to a convenient working

height.

2. Remove the battery and

heat

shield.

3. Remove the heat shield from the turbo

unit.

4.

Unbolt

th e e {haust pipe

flange.

5. U nbo lt

the preheater plate.

6. Remove the

turbo branch pipe.

7. Remove

the

turbo and

s te ad y b ar

se -

curing

bolts

from

t he ex ha ust man i-

fold.

8. Unbol t

th e ste ad y b ar f rom

the

gear-

box casing.

9.

Raise the tail

end of the

engine.

10. Unbol t

the

engine bracket

from

th e

cylinder head and

engine

mounting.

11 . Remove th e gearbQ -oil dipstick

tube.

12.

Undo

th e mani fold nut s and lift

th e

exhaust manifold c om pl et e w it h g as-

k et o ff t he

engine.

To fi t

1. Lift th e exh aust manifold complete

with

new

gasket i nt o p os it ion a nd fi t

th e nuts.

2.

Fit

a

new

gasket

between th e turbo

unit

and

e {haust

manifold

an d fi t the

bolts.

3.

Fit

th e stet.dy bar.

4.

Lower th e engine.

5. Tighten

th e

exhaust manifold.

6. Fit th e

dipstick

tube.

7 . Sec ur e

the

steady

ba r

to th e g ear bo x

casing.

8. Tighten the turbo u ni t to th e

exhaust

manifold.

Exhaust manifold casting 820l turbo

engine

252 3


30/156

9. Fi t the

turbo branch

pipe

and

exhaust

pipe.

10. Fit the

preheater plate .

11.

Fit the heat

shield

over the turbo unit.

12. Fi t

th e

battery

and heat

shield.

13. Lower the car.

Exhaust

manifold: B202

Turbo engine

To

remove

1.

Remove the battery.

2.

Remove the distributor.

3.

Remove

the distributor heat

shield.

4. Disconnect

the

turbo suction inlet

pipe,

pressure discharge .

pipe and

oil

supply pipe

rqm

the

turbo

unit

and

the oil supply

pipe from

the

engine.

5.

Disconnect

th e

electrical

leads

to

th e

solenoid

valve

from the turbo

unit

and

w a s t e g ~ t e valve.

6. Disconnect

the

EGR

pipe from the

exhaust manifold and

EGR

valve.

7. Unbolt the turbo unit bracket from th e

gearbox casing.

8.

Remove

the

dipstick

tube.

9. Disconnec t the oil return

pipe

from

th e turbo

unit.

10.

Unbolt the exhaust pipe from th e

turbo unit .

11.

Remove the

rlu \ s

distance pieces

and

washersfl th e exhaust manifold.

12.

Slide the exhaust

manifold

clear of th e

studs and then r mov it c om ple te

with

turbo unit.

13 . Separate

the

exhaust manifold

from

the

turbo unit .

252-4

X h a u s t m a n i f o ~ d

casting: B202

turbo engine

To t


31/156

To fi t

the

exhaust

manifold

reverse

the

removal procedure.

Fi t new gaskets

to

the joint faces an d

new

securing nuts for the exhaust manifold.

Exhausll: manifold: B2 2 injection engi ne

To

remove

1. Remove the oil filler pipe from

the

gearbox

and

blank

of f th e

opening.

2 S ep ar ate th e e xh au st pipe

from

the

silencer.

3 Remove the

intermediate

manifold

section.

4

Remove

th e

upper

stud

from

th e o ut -

bo ar d f la ng e

of the

outer

exhaust-

manifold

section.

Use a second

nu t

to

lock

th e

securing

nu t

when unscrewing

th e stud.

5 Re mov e t he remaming nuts and dis-

tance pieces

and

t hen f ree

th e

exhaust

manifold

from t he s tuds by raising th e

leading end

to clear th e

enqine moun-

ting.

fi t

Fi t in t he reverse order .

Two piece exhaust manifold casting fitted

t o 8202 injection engine

252 5


32/156

Exhaust system

overview

The exhaust s ys tem compr ise s t hr ee s ec -

tions: t he f ront pipe

section

incorporating

t he fro nt

silencer; the intermedia te

pipe

section incorporating a s ilencer located

forward

of

the rear

a < e; and t he ta il pipe

which discharges on the LH si de under -

nea th the r ea r

bumper

Front

pipe

section

and

clamp

fitted

to

B2 1

turbo

engine

252 6


33/156

252-7

Tail p ipe

Fitted

to

8201

and

8202 turbo

engines

as

from 1984 models.

Longitudinally mounted s il encer in inter

mediate

section

Fitted to

t urb o eng in es >

fr

J 9 L ~

models;

Injection engines without c;etalyl:ic O\ l-

verter as f rom

1985

models;

Carburettor engines as from

1986 models.

Tai l

pipe

section

Fitted to 8201 turbo eng ines

up

to

and

including 1983 models;

Injection

engines

up to

and

including 1984

models;

Carburettor

engines

up to and including

1985

models;

Cars with catalytic converter

emission

control.

Rear

pipe section

Fitted to

820l injection

engines

as from

1985 models;

Carburettor

engines

as from 1986

models;

8202 injection engines;

Turbo engines with

cata lyt ic converter

emission

control.

I nt ermedi at e s ec ti on w it h t ra ns ve rs e

si

lencer

Fitted to 8201 turbo engines

up to

and

including 1983 models;

820l injection engines up to and including

1984 models;

8201 car bur et to r engines up to and in

cluding 1985 models;

8201

engines equipped

with catalytic con

verter

emission

control.

Front pipe section with catalytic converter


34/156

Front pipe section

with

catalyt ic converter

Fitted to

8202 injection

engines.

Heat

shields

Some model variants and cars with certain

market specificat ions

ar e

equipped

with a

heat shield

fitted

b etwe en th e

front

si

lencer and

f loor pan.

Provision in the

form

of

drilled

holes

in

th e

floor

pan sealed with

rubber

blanks

has b een made in all

cars.

Thus,

a heat

shield

can quickly be

fitted

if

problems

attributable

to excessive ar e

experienced.

As from 1984

models,

turbo-engine

cars

have both a front and a rear heat

shield.

u rbo c rs nd c rs with

catalytic

con-

verter

emission

control

B2 1 and B202 engines

Front

heat

shield

Over catalytic converter and front pipe

section

Rea r hea t shield

Over

silencer

in

intermediate section

General descript ion of f itt in g of e xh au st


35/156

system

On normally

aspirated

engines the exhaust

system

is

se cu re d to t he

exhaust manifold

by means

of bol ted

fl an ge j oi nt s. T he MI

nuts

are m ade of s ta inless

steel

and four

ar e

r eq ui red for two piece

manifolds

and

three

for integral manifolds.

T he j oi nt s

ar e

sealed by m ea ns o f f la ng e

gaskets.

Th e system

is

mounted

in

rubber hangers

attached to rigid

hooks

located at

two

points under

th e

floor pan: one se t for the

silencer in the intermediate sec tion for -

ward of the re ar a xl e a nd one for

th e

tail

pipe

section at th e

bumper bracket.

T he t urbo exhaust

pipe

is secured

to

the

pipe f lange by means of three

M

locknuts

which

a re not s ta in le ss

steel.

The f lang e joints seal

by means o f a

taper

fit.

The

front

pipe

section

is

secured

to

the gearbox casing by m ea ns of aU boLt.

n

al l

other

respects the system

is

fitted

in

th e

same

way as

to

normally

aspirated

engines.

252 9

Assembly

and fitting


36/156

Place

a clamp on

t he intermedia te

pipe

section

and on

th e

tail pipe

section

by

sliding the

clamps

over t he s lo tt ed , f la red

end of th e

respective

pipe. 1:0 assemble,

slide

the end of the pipe as fa r as it w il l g o

inside

the flared end of the adjoining pipe.

Hang the y s t n n ~ if l position bu t do not

tighten th e

mOlilTilt i l7Ig s

or

flange

nuts. The

rubber hangers sli-ould hang at an

angle

towards

th e

front o f th e ca r

expansion

of

the pipe

when

ho t

is

approx.

15-20 mm,

which

will

bring

th e hangers into a

vertical

position .

CheCK that the

system

is h an gi ng freely

and

nmt

under tension and that it is no t

fouling th e body

c rossmember or rear

spr ing link . Adjust

th e

run as

necessary at

the pipe joints and by slackening

th e

nuts

on the

exhaust

manifold.

Remember to

retighten a ll nuts after adjustment.

252-10

Tightening

clamps

and jo in ts


37/156

Normally

aspirated

engines

Tighten t he exhaust

man if old f lange . B e

fore t ighten ing

each

clamp,

slide it

over

the

slot

in

t he fl ar ed

end

to

a

position

approx.

9

mm

0 .35 in

from the end. Make

sure that the

pinchbolt

on

the

leading

clamp

is on

top

of the

p ipe and that f or t he

trai l ing clamp underneath the

pipe.

Turbo

engines

o

l

I

i

I

I

Wrong

Right

? ~ ~ . .

; p

Thi s wil l result in

the

wool in

t he exhaust

system

becoming

saturated with oil,

causing

blue

smoke to be

emitted

from

the

ca r for

some considerable t ime afterwards.

void

excess ively power fu l

exhaust

ex tract ion , connect a

hose with an open

couplin:go

If

e>ccessively

powerful

exhaust

extraction

equipment is connec ted to turbo cars,

oi l

may escape

through

th e seals

in

th e turbo

unit.

Connection to e xh au st

~ x t r t i o n equip

ment

When using

exhaust

extraction

equipment

when running th e

engine

in th e workshop,

avoid

excessive depressurization of t he ex

haust system which may affect readings,

e.g.

of th e

CO

content.

Hang the system loosely

in

position. Locate

th e fr on t pipe section

in

the U-bolt

and

secure th e pipe

to

the

flange,

eliminating

al l clearance between p ip e a nd

f lange not

so tight that

the pipe

cannot

be

rotated .

Tighten

th e

U-bolt,

the

leading

and

trailing

clamps

and finally

the f lange jo in t.

252-11

xhaust

system

urbo

cars


38/156

The exhaust system fitted to turbo engine

cars is of a larger

bore

than that on

other

models

bu t

has th e

same

intermediate

and

rear mounting points

and

U bolt c lamp at

the gearbox.

The

exhaust

pipe is

connected to

th e

flange

on the waste gate valve. On cars

of

up to

and

inc luding 1985

models

the f it ting is a

compression

f i tt ing with

an

olive. As from

986 models the connection is a taper

fit.

As from 1984 Turbo models the run of

th e

exhaust system and th e mountings for

th e

intermediate silencer

and

tail

pipe

have

been modified.

The intermediate

silencer

an d

tail

pipe

ar e

of a

new

de:ign b ut c an be fitted to cars as

from

1981

models

with the use of a special

se t of mountings.

252 12

Up to and including 1985 models

As from 1986

models

Removing th e front

muffler


39/156

1.

Jack

up t he c ar .

U ns cr ew t he

b ol t s s ec ur in g

th e f ro nt

exhaust pipe

to th e

exhaust

manifold.

3 Undo th e clamp holding th e connecting

ring a t th e j oi nt wit h t he

middle

ex

haust

p ip e a nd separate

t h e p ip es .

4. Turbo

models:

Undo t he c la mp on

th e

transmission casing.

To r em ov e

th e

rear

muffler

and

th e

other

s ec ti on s o f

pipe,

detach t he r ub be r

moun

tings

and clamps

from

th e

part

to

be remo

ved.

Removal of

middle

exhaust

p i pe a nd

muffler

To

remove th e

middle

exhaust pipe or the

rear

muffler it is best t o b eg in by unclamp

ing

t h e j o in t b e tw e en t h es o t wo

units.

To rem ove th e e nt ir e syste m, first undo

th e

front

pipe from the

exhaust

manifold,

urbo models: Undo also t he c la mp on

th e

transmission

casing

an d then unclamp

th e

rear pipe joint.

Withdraw

th e rear

pipe

f ro m t he rear.

Refit in t he r ev er se o rd er .

Note

A f t er r e fi t ti n g, check th e e x ha u st s y st e m

fo r

leaks and make

sure that th e

pipe is

no t

in

contact

with

th e body.

252-13


40/156

/i

]


41/156

Crankcase ventilation 254-2

Exhaust

emission

control systems

in use 254-2

Lambda sys tem for

8

engine with

LH Jetronic injection system

254-39

F auit d.iagnosis

of

Lambda systf;un Cl

Measuring

the

pulse

ratio

254-32

Fault-diagnosis table 254-35

Fault

diagnosis

of

electricalsystem

254-37

E,{haust gas recirculation EGR system

EGR

valve: On-Off

type 254-12

EGR

valve: Two-port type 254-13

EGR system: Proportional type 254-15

Checking On-Off and

two-port

EGR

systems

254-19

Check ing EGR

systems

situ

proportional

type

254- 20

2543

254-4

254-6

254-31

5 L ~ 3

254-30

254-29

254-30

254-25

254-28

254-28

254-22

254-11

Replacing th e Lambda

controllUnit

Throttle switch - fitting

Replacing th e modulating valve

Oxygen-sensor-regulated injection

system

Lambda

system

Oxygen-sensor-regulated CI injection

system 1984 models 254-24

Electrical

system and control

of oxygen sensor

Enrichment

system

Oxygen

sensor

Checking

t he preheat ing of the

oxygen sensor

Replacing

the oxygen

sensor

Catalytic

converter

Delay valve

Deceleration

devices

Vacuum-controlled

deceleration

valve

Mechanical

throttle

damper

dash

pot

Fuel shut-off on

engine

overrun

Evaporative-loss control

device

ELCD

254-40

254-1

Crankcase

ventilation


42/156

1 Crankcase

2 Exhaust manifold

3

Camshaft

cover

Oil catcher and flame

trap

5 Nipple and restriction

6a Small-bore hose

norm.

asp. engines only

6b Large-bore

hose

7

Inlet

manifold

Crankcase ventilation

7

a 6b5

Carbureted

engines

are

equipped

with a

f lame gua rd at

the vent ilat ion

hose

con

nec tion to air c leaner .

The following exhaust emission

control

systems ar e in use:

Deceleration

devices

Exhaust emission contro l systems in use

Delay

valves

dis tr ibutor vacuum con

trol

To meet

the

exhaust emission

requirements

in

certain markets, special exhaust

emis

sion control sys tems are fitted to cars with

specifications for these markets.

254-2

The

size

of

the var ious hoses

and connec

tions ar e designed

to

ensure efficient eva

cuation of the gases in the

crankcase

into

the engine under al l running conditions.

The

gases

are evacuated

through

t he small

bore

hose

directly

into

th e inle t

manifold

under al l running condit ions with

th e

ex

cep ti on of when

th e

engine is at full load

and of

Turbo cars ,

in which

cases

the

gases ar e

evacuated

t hr ough the

thicker

hose to the

a ir c leaner

and thence to the

engine.

The crankcase ventilation is completely

enclosed. The

ventilation system comprises

a three-way nipple in

the valve

cover,

from

which a thicker hose runs to

the

air

cleaner, and a small-bore hose to the inlet

manifold. Turbo engines

ar e

not fitted with

the small-bore

hose and

the

nipple

i s p lug

ged.

Vacuum-controlled

deceleration

valve

}

Mechanical throttle damper

dash pot

Device for

fuel

shut-off

on engine a

verrun

Exhaust

gas

recirculation

EGR sys

tems


43/156

EGR valve: proportional

EGR

.valve:

On-Off

EGR valve: two-port

Catalytic converters

O>


44/156

1. Run

the engine

until

it and the car

bure tor a re at working temperature.

2.

Run the

ef:lgine

at

idling

speed

and

check that th e deceleration

valve

is

c lo sed. I f in

doubt,

t ur n the

decelera

tion valve adjusting screw

a

f ew tur ns

counter-clockwise.,

3.

Adjust

tne;

~ n t t y

{

fl:Je and engine

speed to ootaTr l ;: he epecified

idling

in

doubt,

the ignition timing

should

a lso be

e.hecked).

4.

Fully

open

the deceleration valve

by

turn.ing: th e

adiusting

screw

clockwise

until

the emgfn8

speed

no

longer

in

creases 1500 -

1800

rlmin apprO) ).

5. Carefully

close

the deceleration

valve

by

t ur ning the adjus ti ng

screw

coun

ter-clockwise until the

valve

just

closes th e

engine

w il l n ow

be

running

at

it s

normal

idling speed).

Then turn

the

deceleration

adjusting screw

a

fur

ther 2 - 3 4

turn

counterclockwise

6. Check t he adjus tment

by

revving up

the

eng in e to

3000

rlmin

approx.

an d

allowing th e

throttle to spring back to

it s

s top pos it ion. Despi te

a

s li gh t d e

lay,

the

engine should unfai lingly

re

t ur n to

the normal idling

speed.

not,

the

deceleration

valve adjusting

screw

should

be

turned counter-clockwise

slightly more.

Mechanical dashpo t

The dashpot mechanically delays

th e

clos

ing of

the throttle.

To

check

1. Run

th e

engine until fully warm.

2.

Connect

a

tachometer

and

se t the

idling

to the prescribed speed.

3.

Increase the engine speed to

3000

rlm in release the

throttle and

use a

stop watch

to

record the time taken

for

th e

engine

to return

to

th e

idling

speed se t

under

point 2.

The

decelerat ion t ime

should b e 3 -6

s.

254-4

Deceleration valve

adjustment

Tool

83 92 748

or

83 92 953

Dashpot, injection engines

To

adjust

Toad

just the deceleration t ime, loosen

the


45/156

locknut on t he da shpot and

screw it

away

from

the

stop on the throttle lever shorter

deceleration

time or towards

the

stop

longer

deceleration time .

Twin carburetted engines, as from 982

models

Remove the dashpot locknut.

Se t

the dashpot

at approximately

the

correct

position.

Tighten the locknut.

Finely

adjust the

dashpot position by

loosening bot h t he mount ing bracket

bolts on the inlet manifold and moving

the

bracket

in

it s ova l holes to the

correct position.

Tighten

the bolts.

1.

Run

th e

engine

until

.warm

and check

that th e CO setting arid

ignition

ar e

correct.

2 Remove the suction advance

pipe.

3.

Rotate

the

throttle lever nd check

that

th e

dashpot

rod

strikes the

stop

at the specified

eng ine speed

check

using tachometer .

Dashpot,

single carburetm

Dashpot, twin carburetors

254-5

Speed

wh ere d ashp o t

strikes

throttle lever

stop Cr

min

.

.\


46/156

254-6

. \

I

As

from 1982

models,

cars

with

USA spec.,

manual gearboxes

and CI fuel

i n je ct io n a r e

i

e qu ip pe d w it h

a system which disconnects

t h e i n je c ti o n

o f f ue l during

deceleration,

to

reduce fuel

consumption

and th e

hydro

carbon

HC) emissio n s.

2500

100

2300

;

100

2200 + 100

2500 100

2200 +

100

2500 100

2000

100

2600 100

3000

100

1985

models onwards:

Th e t h ro t tl e b u tt e rf ly incorporates a

d is c v al ve

actuated

by

th e

depression

raised on

engine

o ve r ru n . T h e

valve

is

not adjus table.

F u e l s h u t- o ff

during

deceleration

4. Re v up th e

e ng in e a nd

check that

the

deceleration

time is correct.

5. Refit t h e s u ct i on

advance

pipe.

1982 models

onwards:

N or m . a s p.

Turbo

E u ro p e i n je c ti o n

a nd T ur bo e ng in es

1981

models

N or m . a s p.

US

only

Norm.

asp.

Canada spec.

Turbo

Canada

spec.

S we de n a nd Switzerland

injection

a nd T ur bo

engines

S we de n a nd

Switzerland

twin-carburetors

Sweden

singlecarburetor

,

;

1

\

Function o f t he

vacuum valve

When current flows

through

the

vacuum


47/156

valve

solenoid 4) from fuse box 2)

vi a t he

d e e l e r ~ i o n

system relay 3 to ground),

the pressure f rom the

inlet

manifold

1)

engages

a

diaphragm and

opens the

by-pass

channel.

3

Operation

When

th e f ue l shut-off deceleration system

is in

operation,

the flow

of

ai r which

normally

passes the air flow

sensor

plate)

is

led through

a

hose and

a

vacuum valve

by-passing the mix tu re con trol

unit see

fig.). This

gives

the result that

the

air flow

sensor plate does no t

lift,

bu t adopts

it s

0

position

so cutting of f the supply of fuel

to

the cy

linders.

The vac uum va lve by -pa ss es th e

ai r

when

the deceleration system relay is

activated.

The

activated

relay a lso g ives a

s igna l t o

the

lambda system, which will be se t at a

fix pulse relation 60 ).

The

deceleration system

relay

is activated

if t he following conditions are obtained:

The

thermoswitch is

closed

coolant

temperature

over 45

0

C 1l3

0

F).

The

time relay is not activated

relay

switch in rest position).

Engine speed exceeds

1575

175

rpm.

5 75

Ai r

cleaner

with

mixture control unit

1 From deceleration

system

relay

2

Vacuum valve

3 From inlet

manifold

4 Air flow

sensor plate

in rest

position

5

By-pass

hose

6 Rubber bellow

7 Filter

8 Fuse box

254-7

8

From

th e

moment

the

throttle

switch

closes accelerator r eleased , the fue l

shut

off deceleration

system will be in

opera


48/156

Acceleration enrichment

time relay

2 Decel er at ion s ys tem relay

c ar with

manual transmission

3 Throttle switch

4

Control

unit Lambda

5

Vacuum

valve

6

Hose

from inlet

manifold

7 Fuse box

8

Ignition coil

S 2 076

Ie E=M ====j

;:: Uf. l

shut-off,

principle

tion.

The system

operates

until the

engine

speed

falls

down to 375 75 rpm.

Throttle switch fault diagnosis

ot

Run the engine to normal temperature.

Detac :l the wiring

connector

fr om th e

throttle switch.

Use

a

buzzer to check

that

an

earth

is

made between t he connect or plug on

:f B

ehrottle

swi tch and

earth

when th e

acceiterator is released.

Conn_ect

the

wiring connector to

the

throttle switch.

254-8

Vacuum valve to check operation of fuel

shut-off


49/156

Connect a Bosch KDJE 7453 meter

alt.

. SAAB pulse relation meter

83 93 597 to

check

the pulse relation.

See Lambda system .

Start the eng ine and

le t

run at 875

rpm

approx.

Detach the electrical connection from

th e vacuum valve.

Measure

the

voltage 12

volts

bet

ween

the connector and earth.

Connect the

electrical

connector

to

the vacuum valve.

254-9

Have

th e

engine idling.

I nc re as e t he

eng ine speed

to 2,000

rpm

approx.,

r el ea se t he

accelerator


50/156

your

hand to feel

if

th e vac uum v al ve

is

operating (will also

be

indicated by a sharp

reduction in

engine

rpm) and that the

Lambda

system

assumes a f ix ed pulse

rela

t ion (60 )

unt il t he system

cuts

ou t

at

375 :t

75

rpm.

O.

2

4

.8 10

I

I

1110

S 7 e

o s ~ i l e

defective

component

>..

co

l)

r..

C

l)

0

E

I

lI

:.:;

>. . .

E

co lI

c

l)

C

l)

r.. co

E

l)

E,b

.c

+-

.

+-

>

c

l _ u

0

0

-

co

::J

1;; co

r..

C

I

>

..::J

c

c

::J 0

I

C

l)

U

.c

C

r..

C

co

C

lI

.8

E

.

C

.8

0

.

l)

co

0

.c

lI

::J

U

co...,

co

l)

r..

.

l)

+-

r..

co

l)

l)

0

c

.

-

. 1

l)

.0

l)

lI

l)

r:J >

lI

E

r..

U

3

l)

co

u

.J

co

OS

c:1:

Q.

-J

-

Possible

causes

Fuel shut-off not operating

Incorrect pulse

ratio,

when

system

e

0

operates

254-10

Delay valve

On some models,

a

delay valve is

fitted

in


51/156

th e va cuum

line between

the carburetor

throttle housing and

th e

vacuum

advance

control

unit

on

t he d is tr ib utor . The v alve

r-8tards

dep ress ion formation for

a

given

time,

as

shown

th e tab le bel ow . Thi s

results

in a

delay

in

the

ignition

advance

and

a consequent reduction

in

the emission

of

oxides

of

nitrogen

(I \l0x)

Delay valve,

colour code

marking

Brown

White

Green

Delay time

2 + 1 s

6 + 2

s

20 +4 s

To check

A stroboscopic

timing

light, tachometer

and stop wat ch a re required

to

c ar ry o ut

this test.

1.

Connect the

tachometer and

the stro

boscopic

timing

light.

2.

Run the

engine

at normal

idling speed.

3. Have an assistant r ap id ly open the

throttle and

run

the engine at

r/min

approx. Start

the

stop watch

when the

throttle

open.

4.

Observe

the

ignition

timing

in the

light given by the stroboscopic timing

light. Vacuum advance should

occur

after the specified

time

see table .

A

faulty

delay valve

should

be renewed.

Note

The coloured

end

of the

delay

valve

should

always

face

towards the vacuum advance

control unit

on

the distr ibutor .

It is

o

important

that the valve

is

fitted with the

shorter hose running between the valve and

the vacuum advance control

unit.

Note

If it is

necessary to remove the suction

p ipe, e .g .

when checking the ignition

tim

ing

the

hose should

a lways be

detached at

the carburetor

end

throttle

housing

to

prevent d ir t entering th e hose and

blocking

the d el ay valve.

254-11

Exhaust ga s recircuiation s ys tem

EGR)

Recirculating a

small

a mo un t o f

the ex


52/156

haust gas es to the intake side of

th e

engine

reduces

th e

eombllstion temperature,

which helps to reduce

th e

emission of ni

trogen. oxides (NO

EGR gases

ar e

le d

frOJlT

~ e d ~ v { r r k

(IF Check

that

the valve

shaft

rotates

iU 1J..,..J,.,t.(... , freely. Replace faulty

r k ~ g i n g pressure regulator valve.

Possible

cause

Not possible to adjust

basic pressure as

detaile? ( , If. I

(1

lAN

w J

- ~ { . t . . je;

1

~

Fault diagnosis

table

fo r basic charging pressure

(APe)

Symptom


147/156

d vvc

Note

Can be temperature sensitive .

Clean orifice.

291 39

Blocked orifice in the sole-

noid valve hose connection to

the turbocompressor connec-

tion

C ).

au

lt

d

iag

n

os

is t

ab

le

fo

r

e

co

m

po

n

en

ts

Sy

m

pt

om

P

os

sib

le

c

au

se

R

em

ed

y

re

fe

rs

t

o A

P

C

sy

ste

m

)

So

len

llll

iid

: v

ail

l\ 'e

o

ot

fu

nc

tiio

ni

nig

J

w

f.T

efil

i A

PC

s

ys

te

m

t

es

te

df

l c

a[

a

s

of

co

m

p

on

e n

tsR

;

T

h

e

co

nt

ro

l un

it

h

as

no

vo

l

ta

ge

b

et

w

ee

n

te

rm

in

al

4

(

+)

aFl

d 6

g

rou

n

d

-)

.

N

o

te

o

T

h

e

w

ir f

ng

ha

rn

es

s

connec t o r shou ld be

lef t

C

i:G

lil

ne

ate

d to

th

e

co

nt

ro

l u

ni

t

d

a r

in

g t

he

me

a

su

re

me

n

t;

.

I

Ch

e

ck

th

at fu

se

19

ha

s

no

t

bl

ow

n

.

R

em

o

ve

an

y

ox

id

ati

on

pr

es

en

t.

C

he

ck

th

e

w

iri

ng

i

n th

e

co

n

ne

c

to

rs

a

t d

is

tr

ibu

to

r p

a

ne

l

fu

se

b

ox

) a

n

d c

on

tr

ol

un

it

.

Check

that

the

(+)

and g round

-

)c

ab

les

a

re u

n

da

ma

g

ed

.

Re

ct

if

y

a

s

r

eq

ui

re

d.

C

he

ck

e

le

ct

ric

al c

on

n

ec

ti o

n

a

t

th

e

co

nn

ec

to

rs

in t

he

en

gi

ne

co

m

pa

rt

m

en

t a

nd

on

t

he

co

nt

ro

l

u

ni

t).

R

e

ct

if y

as

r

eq

ui

re

d.

,

(}

' .

..

\

~

L

oo

se

co

n

ne

ct

or

o

n

kn

oc

k

de

-

t

ec

to

r.

Br

ok

en

c

ab

le

b

et

we

en

k

no

ck

de

c

ec

to r

an

d

c

on

tr

ol

un

it .


148/156

C

h

ec

k t

ig

ht

ne

ss

. S

ee

u

nd

er

Re

m

ov

in

g

an

d

re

fi t

ti

ng

of

com-ponents,

knock

de tect or.

T

e

st s

ys

te

m w

it

h

k

n

ow

n

go

od

co

nt

ro

l

un

it .

I

f

sy

mp

to

m

s

d

is

a

pp

ea

r,

re

p

lac

e

d

ef

ec

ti

ve

c

on

tro

l

un

i.t

.

Ch

e

ck

th

e

pr

es

su

re

s

wi

tc

h.

S

ee

un

de

r

Ch

ec

k

ing

c

o

mp

o

n

en

ts

, ch

ec

ki

ng

th

e

pr

es

su

re

t

ra

ns

du

ce

r

.

C

h

ec

k th

e

so

le

no

id

v

al

ve

. S

e

e

u

nd

er

C

h

ec

ki

ng

c

om

p

on

en

ts

,

c

he

c

kin

g

t

he

s

ol

en

oi

d v

al

ve

.

T

es

t

sy

st

em

w

ith

kn

o

wn

g

oo

d

k

no

ck

d

e

te c

to

r.

If s

ym

p

to

m

s

d

is

ap

pe

ar

,

re

p

lac

e

de

fe

ct

iv

e

k

no

ck

de

te

ct

or

.

f /-

C-

v-

-

v

K

n

oc

k

de

te

ct

or

n

ot p

ro

pe

rl

y

t

ig

hte

n

ed

.

F

a

ul

ty

pr

es

su

re

tr

an

sd

u

ce

r.

F

au

lt

y c

o

ntr

ol

un

it

.

Fa

ul

ty

kn

o

ck

d

et

ec

to

r.

S

o l

en

o i

d v

al

ve

n

ot

f

un

c

tio

n

in

g de

sp

it

e

s

up

p l

y

gr

ea

te

r

th

an

5 v

olt

s.

o

t o

Th

e

so

len

o

id

e

le

ct

ric

al

co

n

ne

ct

or

is

t

o r

em

a

in

co

nn

e

c

ted.

29

1

-40

Fault-diagnosis

t able for

e system

Symptom

Maximum

charging

pressure too low

low engine output)

Possible

cause

Incorrectly adjusted basic

pressure.

Loooe

or oxidized

electrical

connections

in

the APC-System.

.

P

t ,I

/ ~ r r l C . J . T i ~ L ~ 1 J \ - l

Remedy

Check

the basic setting ,of the

charging pressure

T8 guJ1at Glr valve.

See I Adjllsting th e basi,c pressure

of tine charging ,pressure regulator .

Check electrical-connections

of cont rol

u n i ~ ,

b u l ~ h e a d

connector,

pressure

trar.lsducer

2

conneotililns) fuel.pump

elay,

knock detect.or pl.lJg and

common

ground in .the :eng ine compartment.

Also ch Bck ,for broken cables in

the .knock

;detector-to-control

unit, pressure switch-to-control

uni t, or fuel pump r el ay to con trol


149/156

;.

, .

l r

Defective (short circuit) st:op

light

~ ~ : ~ r

Ft- V : : 1 ~

Faul y or wrongly djusted

cruise

control

vacuum

switch

T-16).

Faulty knock detector.

Faulty

pressure transducer.

Solenoid valve does

not

open.

Faulty control

unit.

uni t, w ir ing. Rectify

i required.

Replace.

Adjust switcm ,or if.eplac.e

replace if

defecti

ve

Test system

with

know.n .good

knock

detector. If ~ s Y I J ; , , ~ t . o m s

disappea:r, knook detector

wa s

at

fault . Replace.

Check

the

pressure transducer.

See

Checking the

pressl:Jne

transducer . Replace th e pres

sure

transducer

if requEred.

Check the solenoid valve. See

Checking

the solenoid

val

ve

under

Cheoking compo

nents . Replace faul ty

solenoid valve.

Test system with knc\wn good

knock control

unit.

H

syo ptoms

disappear, control ,}l1 it was

at

faul t. Replace.

291-41

Fa

ul

t- d

ia

g

no

si

s

ta

bl

e fo

r

e

sy

st

em

S

ym

p

to

m

P

os

si

bl

e c

au

s

e

T

h

e kn

oc

k

de

te

ct

or

re

gis

te

rs

a

bn

or

m

al

en

gi

ne

v

ib

ra

tio

ns

.

F

a

ul

ty

sp

rin

g

or

st

ick

in

g

ro

d

i

n

the

d

ia

ph

ra

g

m

u

ni

t.

Fa

ul

ty

tu

rb

o

co

m

pr

es

so

r.

Re

m

ed

y

C

o

nn

ec

t

th

e

te

st

w

iri

ng h

ar

n

es

s w

it

h s

er

vi

ce

b

ox

8

3

93

5

48

o

r

83

94

0

74

as

ap

pr

op

ri

at

e)

, (

se

e

'C

he

ck

in

g

th

e.

AP

C s

y

ste

m

k

no

cv

.

co

nt

ro

')

.

I

f t

he

LE

D

f

la

sh

es

w

he

n

d

riv

in

g

under light load li sten for

ab

no

rm

a

l

en

gi

ne

n

oi

se

. t

he

e

n

gin

e s

ou

nd

s

n

or

m

al tr

y

a

n

ew k

n

oc

k

de

te

ct

or

.

T

ry

a n

ew

d

iap

h

rag

m

un

it

.

Re

m

ov

e t

he

e

xh

au

s

t

el

bo

w

a

nd

th

e

in l

et

to

th

e

,


150/156

C

ha

rg

in

g p

re

ssu

re

to

o

hi

gh

(a

lso c

ov

e

rs

v

io

le

nt

c

ha

ng

es

in

ch

ar

gi

ng

pr

ess

u

re

d

ur

ing

ac

ce

ler

at

io

n)

. Pr

es

su

re

sw

i

tcl

l

cu

ts

o

uf.

2

91

-4

2

L

e

ak

in t

ur

bo

co

m

pr

es

so

r

-

s

ol

en

oi

d h

o

se

.

L

e

ak

n s

ol

en

oi

d

va

l ve

-

di

ap

hr

ag

m

un

it

ho

se

.

L

ea

k

in

di

ap

hr

ag

m

u

n

it .

R

u

pt

ur

ed

d

ia

ph

ra

gm

un

it

.

L

e

ak

i

n

ho

se

to

p

re

ss

ure

t

ra

ns

du

c

er

.

F

au

lt

y

pr

es

su

re

tr

an

sd

uc

er

.

S

ole

n

oid

va

lv

e

do

e

s no

t s

hu

t

d

u

e

to

st

ick

in

g

v

a

lv e

sp

oo

l.

B

lo

ck

ed

or

if

ic

e i

n t

he

s

ol e

n

oid

ho

se c

on

ne

ct

io

n

to

th

e

t

ur

bo

co

m

pr

es

so

r

(c

on

ne

ct

io

n

lC

).

co

m

pre

ss

o

r.

C

h

ec

k

vi

su

all

y t

ha

t t

he

tu

r

bi

ne

wh

ee

l a

nd

t

he

co

m

pressor are not damaged.

Re

p

la

ce

f

au

lty

t

ur

bo

co

m

pr

es

so

r.

C

h

ec

k

f

or

le

ak

s. R

e

pl

ac

e

fa

ul

ty

ho

se

.

Ch

e

ck

fo

r

l

ea

ks

.

Re

pl

ac

e

fa

u

lt y

ho

se

.

C

he

ck

fo r

l

ea

ks

. Re

p

lac

e

f

au

lty

di

ap

hr

ag

m

un

it

.

Ch

e

ck

fo

r

le

ak

s.

Replac e

f

au

lt

y

di

ap

hr

ag

m

un

it

.

Ch

ec

k t

he

m

ou

nt

in

g o

f t

he

d

ia

ph

ra

gm

u

ni

t h

ou

si

ng

o

n

th

e b

ra

ck

e

t.

R

e

pl

ac

e

fau

lt

y

di

ap

hr

ag

m

u

ni

t.

C

he

ck

f

or

l

ea

ks

. Re

p

lac

e

ho

se

.

C

he

ck

p

re

ss

ur

e tr

an

sd

u

ce

r.

Se

e

'C

he

ck

in

g p

re

ss

u

re t

ra

ns

du

ce

r'

.

fault

y p

re

ss

ur

e t

ra

ns

u

ce

r.

C

he

ck

th

e

A

P

C s

ys

te

m

in th

e

ca

r.

R

ep

la

ce

fa

ul

ty

so

len

o

id

va

lv

e.

N

ote

o C

a

n

b

e t

em

p

er

at

ur

e-

se

n

si

tiv

e.

C

h

ec

k

a

nd c

le a

n

or

if

ic e

as

n

ec

e

ssa

ry

.

Symptom

Possible

cause

Incorrect

basic chargi ng pres

sure

setting.

::Jhort

circui

t in th e

pressure

ansducer si gnal

circuit.

Faulty control unit.

Shaft sticking in th e

pn essure regulator valve.

Remedy

Check

th e

basic

setting of th e

charging

pressure

regulator

valve

with

th e ca r

on

th e

r oa d . S e e

Checking th e basic

setting

of th e

charging

pressure regula

to r

on t he r oa d .

Adjust

as necessary.

Check th e wiring b e tw e en p r es

sure t ransducer

an d t h e c o nt r ol

unit. Rectify s h or t c i r cu i t.

Test system wi th known good con

t rol unit . Replace control u ni t i f

defective.

Remove th e seal an circlip.

Unhook

th e

diaphragm

unit

push

rod

from

t h e r e gu l at o r

valve

c on tr ol a rm s tu d. C he ck

that


151/156

t Jormal

charging

pres

s ur e b ut no pressure

reduct ion despi t e in

tensive knocking/pin

king

Sticking di aphragm unit push

ro d bush

AP C

system no t

functioning.

Ba d contact in th e knock de

tector

wiring.

Knock detector not

properly

tightened.

Faulty

knock detector.

F a ul t y c o nt r ol

unit.

Beari ng st i cki ng in

t he c h ar

ging pressure regulator valve.

th e valve

shaft

rotates easily.

R e pl ac e f au lt y c ha r gi ng

pressure

regulator valve.

Replace

diaphragm

unit.

Se e Checking t L\P

sys

te m

knock control .

Check

t h e c o n ne c to r b e tw e e n

th e knock

detector an d th e

ca r

wiring harness.

Check t i ght ness. Se e Remov

and

refitting

of components

knock detector .

T

es t

system wi

th

known good

knock detector.

If

symptoms disappear knock

detector

wa s

at fault. Replace.

T

es t

system wi th known good

control unit .

If symptoms di sappear

control

unit

was at fault. Replace.

Remove

th e seal and circlip.

Unh

Documents

2.4 - Exhaust System, Cooling System, Turbo System [OCR]