Page 241
3. Check that there is no air leaking from between the
air flow sensor and the engine.
/4~
G...
t
~
.
\"
\~
""'-~
CHECKING THE FUEL FLOW
CHECKING FOR LEAKING AIR
3. Check the CO-value (warm engine).
Poor performance, low top speed
1. Check that the throttle valve opens fully when the
j:i1::ua1 •~ 1u11y Ut:!Jlt:~~i:u.
S 5202
CHECKING THE CO-VALUE
4. Check the fuel atomization of the injection valves.
Deposits on the spark plugs can give an indication of
poor atomization.
S 5206
CHECKING THE THROTTLE VALVE
2. Check that the fuel flow is sufficient by measuring
the quantity of return fuel flowing during a 3-second
period. See under "Fuel pump capacity".
Faults can be caused by:
A faulty fuel pump
Low voltage of the supply to the fuel pump
A blocked filter or blocked fuel lines
S S209
CHECKING THE INJECTION VALVES
SAAB
240-39
Page 242
Disconnect the fuel distributor from the air flow sensor, ensuring that the control plunger does not fall out.
Extract and inspect the control plunger (avoid handling the sealing surfaces). Clean t: .e plunger in petrol,
install it~nd mount the fuel distributor. Never dismantle the fuel distributor any further.
Irregular CO-value and idling speed, difficulty in adjusting
1. Check that no air is leaking from between the air flow
sensor and the engine.
--.
CLEANING THE CONTROL PLUNGER
-- .
·~- 1..;nec1<
tnat tne c:11scin tne aux111ary air valve 1s not
sticking.
CHECKING THE AUXILIARY
CHECKING THE AIR FLOW SENSOR
240-40
~
S5211
CHECKING FOR LEAKING AIR
2. Check whether any parts of the air flow sensor are
sticking as follows:
Run the engine until it is warm and then connect
a t;U-meter.
Switch off the engine and then restart it without
touching the accelerator. Read off the CO-value.
Rev the engine to around 3.000 rev/min and then
allow it to return to idling speed. If the CO-value
is different now to the earlier reading, then either
the control plunger or the lever is sticking.
Check that the lever moves freely.
- ..)
SAAB
AIR VALVE
1
1
1
.
Page 243
High fuel consumption
1. Check the CO-value (warm engine).
55209
S 5202
CHECKING THE INJECTION VALVES
CHECKING THE CO-VALUE
4. Check that the cold start valve is not leaking.
2. Check the control pressure with the engine warm. Insufficient control pressure implies a fuel-to-air ratio
which is too rich.
CHECKING THE COLD START VALVE
5. Check that there is no external leakage of fuel.
CHECKING THE CONTROL PRESSURE
3. Check that the injection valves atomize the fuel. Deposits on the spark plugs can give an indication of
poor fuel atomization.
SAAB
240-41
Page 244
1
1
1
1
•
•
,
-
Page 245
EXHAUST SYSTEM
REMOVAL OF CENTRE EXHAUST PIPE AND
MUFFLER AND/OR REAR PIPE
REMOVING THE FRONT MUFFLER
To remove the middle exhaust pipe or the rear muffler it
is best to begin by unclamping the joint between these
two units.
To remove the entire system, first undo the front pipe
from the exhaust manifold and then unclamp the rear
pipe joint. Withdraw the rear pipe from the rear.
Reassemble in the reverse order.
1. Jack up the car.
2. Unscrew the screws securing the front exhaust pipe
to the exhaust manifold.
3. Undo the clamp holding the connecting ring at the
joint with the middle exhaust pipe and separate the
pipes.
..
To remove the rear muffler and the other sections of pipe,
detach the rubber suspensions and clamps from the part
to be removed.
NOTE
After assembling, check the exhaust system for
leaks and make sure that the pipe is not in contact
with the body.
.•
EXHAUST SYSTEM
252-1
Page 246
,
1
1
1
Page 247
EXHAUST EMISSION CONTROL SYSTEM
Description
To meet the requirements governing the exhaust emission
standards existing on certain markets, cars for these markets are equiped with special exhaust emission control
systems. The following systems exist for exhaust emission control:
Sweden
Model 1975
Carbu,·
retor
engines
· Fuel
injection
engines
Carbureted engines
Fuel injection
engines
Manual
transmission
Automatic transmission
Manual
transmission
Automatic transmission
xJ>
xJl
Deceleration
valve
x.n
x2l
x2>
Temperature
compensator
X
X
X
Delay valve
xs1
Carbureted
engines
Fuel
injection
engines
TURBO
Europe
and
Sweden
x11
xJl
x4l
x6l
x8)
1) Vacuum-controlled
2) Up to and including 1977 model vacuum-controlled, as from 1978 model electrical speed control
3) Up to and including 1979 model vacuum-controlled, as from 1978 model dashpot
4) Dashpot
5) Delay 6 ± 2 secs.
6) Delay 20 ± 4 secs. (Sweden only)
7) "On-off"
design
8) Up to and including 1977 model "on-off",
I~
I
I
I
I
I
I
I
.
X
xs>
x11
EGR
Europe
As from model 1976
Sweden
As from model 1976
as from 1978 model "two-step".
264-1
Page 248
Cars with fuel injection engines, 1977-1979 model have
a vacuum-controlled valve located on the inlet manifold.
Decelerationdevice
The deceleration device is designed to maintain combustion during engine overrun to prevent the emission of
unburned hydrocarbons.
The following designs of deceleration devices are available:
Vacuum-controlled, carbureted engines
Vacuum-controlled, fuel injection engines
Electric speed control
Dashpot
+-
Vacuum controlled deceleration device, carbureted
engines
Cars with carbureted engines, (Sweden up to and including 1977 model) have a vacuum-controlled valve in the
carburetor (seeS section 231 ).
~5634
DECELERATION
1977 MODEL.
VALVE, INJECTION ENGINES AS FROM
Decelerationvalve, fuel injection engines
Checking
1. Run the engine until it is thoroughly warmed up.
2. Connect a tachometer and adjust the idling speed to
875 r.p.m.
3. Rev the engine to 3000 r.p.m. and measure the time
(with a stop watch) between the release of the throttle and the moment at which the engine returns to
875 r.p.m.
The deceleration time should be:
1976 model
4-5 sec
As from 1977 model
4-6 sec
___
DECELERATION
......_......._ ______
S5214
CAUTION
The readings will be faulty if the radiator fan cuts in
while the deceleration time is being measured. This
can be avoided by disconnecting the wire to the
thermo-switch for the fan for a few moments while
the time is being recorded.
VALVE, CARBURETED ENGINES
Vacuum-controlled deceleration device, Cl
Cars with fuel injection engines, 1976 model, have a
vacuum-controlled valve situated at the throttle butter·
fly.
S 5215
DECELERATION
254-2
VALVE, INJECTION ENGINE, 1976 MODEL.
SAAB
Page 249
Adjustment, up to and including 1976 model
1. Remove the rubber bellows between the air flow sensor and the throttle housing.
2. Undo the lock nut on the valve screw and turn the adjustment screw the number of turns specified on the
adjustment graph. Tighten the lock nut.
3. Fit the rubber bellows.
4. Repeat this procedure.
Adjustment, as from 1977 model
1. Connect the tachometer and run the engine until
warm.
2. Unscrew the adjustment screw until the valve closes
~letely.
Example: On checking a deceleration time of 3 seconds
is recorded. Locate the no. 3 on the time axis of the
graph (the vertical axis). Follow 3 horizontally across
the graph until it intercepts the curve and then read off
the corresponding value on the horizontal axis. In this
case the figures is 1 1/3 turns in a clockwise direction.
ADJUSTING THE DECELERATION
1977 MODEL
ADJUSTING THE DECELERATION
VALVE, AS FROM
3. Adjust the screw on the throttle housing until the idling speed is correct.
4. Turn the adjustment screw until the engine is running
at 1600 r.p.m.
5. Back off the adjustment screw two turns from this
position.
6. Use the adjustment screw on the throttle housing to
trim the idling speed.
7. Check the deceleration time and make any small adjustments necessary.
VALVE, 1976 MODEL
Tool 83 92 466 and screwdriver
1----,--,--,---,---,--,---,,---,--,---,
o.ctl••lion
li.,,,.inHCOtlm
Numbe1 of tu,n,ot
$5150
,.
~IUll•_.....,.._
meni KrtwClOCKWlSE
Nu~
o' 1u1n1of «11uHmen1
,c, .... cou'IITeA-ClOCKWISE
ADJUSTMENT GRAPH FOR DECELERATION
VALVE
SMII
254-3
Page 250
Electric speed-control!decelerationdevice
The solenoid serves as a variable idling stop. During en~
gine overrun, the idling speed is increased (approx. 1550
r.p.m.) if the speed of the car exceeds 10 m.p.h. (30
km/h).
Cars with carbureted engines, as from 1978 model have
an electrically-controlled deceleration device consisting
of a speed transmitter connected to the speedometer
cable and a solenoid at the carburetor (carburetors).
Checking
Checks should cover the setting of the deceleration valve
(increased idling speed) and the function of the speed
transmitter (cut-out speed).
A. Engine speed (solenoid setting):
1. Run the engine until it is warm and connect a tachometer.
2. Disconnect the+ cable from the solenoid and connect
battery voltage to the solenoid.
3. Rev the engine and then release the throttle. Check
that the idling speed increases to 1500 r.p.m.
Adjustments should be made on the solenoid adjustment screw and the new setting should be checked by
revving the engine again.
SPEED TRANSMITTER MOUNTED ON DASH PANEL SHELF
TOTHELEFTOFTHEFAN
ADJUSTING THE SOLENOID
SOLENOID LOCATED AT CARBURETOR, SINGLE CARBURETOR ENGINES
CAUTION
The solenoid does not open the throttle valve. It's
function is merely to prevent the throttle closing
completely during engine overrun at speeds in.
excess of about 18 m.p.h. (30 km/h)
SOLENOID LOCATED AT CARBURETOR, TWIN CARBURETOR ENGINES
254-4
SAMI