Page 21
a) Adjust the idling speed by means of the idle adjusting
screw on the throttle valve housing.
SETTING THE IDLING SPEED
j on the fuel distributor.
} Clockwise — richer mixture.
Anticlockwise — leaner mixture.
¢ { ) b) Adjust the CO-setting be means of the adjusting screw
ADJUSTING THE CO-VALUE
These adjustments effect each other, for which reason
the adjustments should be carried out in steps.
5. Catalyst cars: Connect the oxygen sensor wire after
the catalytic converter {as from model 1980). Move
» rr the CO-meter sond to the rear end of the exhaust
: pipe and fit the plug in the front exhaust pipe. The
CO value measured at the rear end of the pipe should
be less than 0,4 % (heated converter).
Lubricate the plug in the exhaust pipe with “NEVER
SEIZE”, MOLYCOTE 1000” or similar to prevent it
from beeing burnt stuck. |
CAUTION
Remove the Allen key from the adjustment screw |
| after each adjustment. If the key is left in the screw
| and the engine reved up the lever could be damaged,
Dismantling and assembly
repairs and adjustments
FUEL PUMP
Removal, metal tank up to and including 1979 model
1. Disconnect the battery to prevent flashover and the
risk of fire when the fuel tank has been opened.
2. Roll back the carpet in the trunk compartment (Saab
99 Combi Coupé: Remove the rear floor cover and
floor panel in the luggage compartment), and remove
the circular cover plate on top of the pump mounting,
3. Remove the rubber cover from the Pump and discon-
nect the electric terminals at the pump,
4. Disconnect the fuel line from the pump. Hold the
pump by means of an Open-ended spanner when loos-
ening the connection.
oe ee
DISCONNECTING THE FUEL LINE
5. Using tool 8392433, turn the Pump mounting anti-
clockwise to the nearest groove, to unlock the bayonet
socket. Lift out the pump unit and save the O-ring.
TURNING THE FUEL PUMP
Tool 8392433
240-21
Page 22
er are
LIFTING OUT THE FUEL PUMP
NOTE
The pump can only be removed in one position, as
one of the bayonet tongues are wider than the others.
6. Suitably cover the tank opening.
Dismantling, metal tank
Release the clips and remove the splash guard and pump
mounting from the pump.
Sella
4 jsseat
FUEL PUMP, DISMANTLED
1. Bayonet socket
2. Adapter
3. Fuel pump
4. Splash guard with suction strainer up to and incl. model 1976
5. Splash guard with suction strainer as from model 1977
240—22
Assembly, metal tank
Assemble the pump unit as shown in the
Note the following:
a. Rotate the pump in the mounting so!
electric connections are in line with
of the bayonet socket which is equips
groove. If this is neglected, the electrs
be in the way of the fuel line.
b. Rotate the splash guard so that the in
the right, looking towards the front 0
wide tongue of the bayonet socket eq
locking groove must point towards th
car.
MOUNTING POSITION OF THE SPLASH G
A. Wide bayonet tongue, equipped with a lo«
B. Driving direction of the car
C. Splash guard indent
c. The distance from the bottom of thi
the top of the pump mounting shou
mm).
Page 23
3. Install the pump unit in the tank as follows:
— Tilt the + electrical connection to the left (as seen
from the direction of movement of the car).
_— Tilt the suction strainer inlet 45° backwards to the
right (as seen from the direction of movement of
1. Clamp 5. Bellows
2. Sealing collar 6. Suction strainer the car).
3. Pump support Removal is in the reverse order.
4. Fuel pump
Installation (plastic tank, 1980 mode!) ff
1. Position the pump on the mounting so that the dis-
tance between the base of the suction strainer and the
upper edge of the rubber mounting is 236 mm (9.2 in.)
236 mm
9.29”
2. Check that the fuel return pipe is connected to the
splash guard holder in the bottom of the fuel tank.
240-24 SAAB
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Page 24
Line pressure regulator
The line pressure regulator is located inside the screw
plug at the return line and return connection from the
contral pressure regulator,
The regulator comprises the following:
1. Piston with O-ring
2, Spring
3. Shims
4. Screw plug with O-ring and washer.
(The screw plug contains a shut-off valve which closes
the return line from the central pressure regulator
when the fuel pump is not operating. The socket
head screw in the plug should not normally be removy-
ed.)
An 0.17 mm shim produces a change in pressure of
0.15 bar (kp/cem2},
After replacement of the O-ring, the line pressure must
be checked and adjusted if necessary.
The pressure can be increased by fitting additional shims
and decreased by removing shims.
The shims are available in thicknesses of 0.004" and
0.020" (0.1 and 0.5 mm). An 0.004" (0.1 mm) shim pro-
duces a change in pressure of 0.15 bar (kp/cm?).,
A prerequisite for measuring and adjusting the line pre-
sure is that the fuel pump Capacity is correct,
The screw plug should be tightened with a torque of 13—
15 Nm (9.4—10.8 ft.lb.. 130—150 kpm).
LINE PRESSURE REGULATOR
|, Piston with O-ring
2, Coil spring
3, Washers
4. Screw plug with O-ring anc sealing washer
lCOntaINS a stop valve for the fuel return from
the warm-up requlator/boost COntral circurt}
Page 25
ADJUSTMENT OF IDLING SPEED
To adjust the idling speed, turn the adjustment screw on
the throttle valve housing by-pass passage.
Adjustment should be made in connection with setting
of CO-value. See adjustment of idling speed.
ADJUSTMENT OF IDLING SPEED
FAULT-TRACING
In the fault-tracing procedure described below it is as-
sumed that the engine does not have any mechanical
faults and that the ignition system is working properly.
Starting difficulties, cold engine
1. Check the operation of the cold start valve. Remove
the valve and place it in a container. Fuel should be
ejected from the valve when the starter motor is
switched on and when the engine is colder than +1 13°F
(+45°C). The injection time depends on the tempera-
ture.
CHECKING THE COLD START VALVE
iba SADB
. Measure the control pressure with the engine cold.
in the event of failure, check:
The cold start valve
The thermal time switch
The electrical system
kp/cm
2,5
2,0
1,5
1,0
0,5
0 10 20 30 40 «°C
S$ 6243
WARM-UP REGULATOR O 438 140013 AND
0 438 140 020 (UP TO AND INCL. MODEL
1976 AND NON-CATALYST CARS AS FROM
MODEL 1977)
kp/cm4]
2,5
2,0
1,0
0,5
0 10 20 30 40
S 6244
WARM-UP REGULATOR 0 438 140 032
(CATALYST CARS AS FROM MODEL 1977)
kp/cm
2,0
1,5 rf 3
1,0
0,5
0 10 20 30 40 %
WARM-UP REGULATOR TURBO S$ 6318
1.0 430 140 051
Page 26
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3. Check that the auxiliary air valve is open when the en- Starting difficulties, warm engine
gine is cold.
1. Check the residual pressure in the fuel system after
the engine has been switched off. Excessively low
pressure when the engine js still warm can cause Va-
porization in the fuel lines,
Check the tightness of the system.
Check first with the valve Open. In the event of leakage,
repeat the test with the valve closed (control pressure
regulator disconnected).
$5201
CHECKING THE AUXILIARY AIR VALVE
4. Check the CO-value (warm engine).
CHECKING THE FUEL PRESSURE
$5202 Possible leakage places:
— Control pressure regulator
CHECKING THE CO-VALUE ~ Non-return valve at fuel pump
— Cold start valve
— Line pressure regulator
5. Check for air leakage between the air flow sensor and — Injection valves
the engine. — External leakage
2. Check the control pressure with the engine warm.
CHECKING FOR LEAKING AIR
CHECKING THE CONTROL PRESSURE, WARM ENGINE
Saag =
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Page 27
3. Check the CO-value (warm engine).
J
$ 5202
CHECKING THE CO-VALUE
4. Check the rest position of the air flow sensor plate in
the air flow sensor. (The top of the sensor plate should
be level with or slightly lower than (max. 0.02 in., 0.5
mm) the lower edge of the air venturi.) Adjust by
means of the wire loop (A).
‘ .
l tb) ia
‘o-085 mm
Aa
SENSOR PLATE IN REST POSITION
240-34
Poor running during the warming-up period
1. Check the control pressure with the engine cold. Ex-
cessive control pressure during the warming-up period
produces a fuel-to-air ratio which is too lean.
kp/cm
2,5
2,0
15
0 10 20 30 40 %
S$ 6243
WARM-UP REGULATOR 0 438 140013AND 99
0 438 140 020 (UP TO AND INCL. MODEL
1976 AND NON-CATALYST CARS AS FROM
MODEL 1977)
kp/cm
2,5
2,0
1,0
0,5
30 40 %
S 6244
WARM-UP REGULATOR 0 438 140 032
(CATALYST CARS AS FROM MODEL 1977)
0 10 20
kp/cm
2,5
2,0 -
ri
1,5 F
Hh
1,0
05
] 10 20 30 40 «%
WARM-UP REGULATOR TURBO mss
0 430 140 051
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Page 28
2. Check the CO-value (warm engine).
J
CHECKING THE CO-VALUE
3. Check that there is no air leaking from between the
air flow sensor and the engine.
ae
\
CHECKING FOR LEAKING AIR
4. Check that the warming-up period for the engine is
normal by observing the temperature gauge. An abnor-
mally long warming-up period may be caused by a
faulty thermostat.
$5202
a
THERMOSTAT
Poor running, warm engine
1. Check the CO-value (warm engine).
oat J
$5202
CHECKING THE CO-VALUE
2. Check the control pressure with the engine warm.
CHECKING THE CONTROL PRESSURE, WARM ENGINE
SAAB a0-26
Page 29
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3. Check that there is no air leaking from between the
air flow sensor and the engine.
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CHECKING THE FUEL FLOW
a
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
pedal is fully depressed.
J
$ 5202
CHECKING THE CO-VALUE
4, Check the fuel atomization of the injection valves.
Deposits on the spark plugs can give an indication of
36206 poor atomization.
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
— Ablocked filter or blocked fuel lines
CHECKING THE INJECTION VALVES
240-36
SAAB
Page 30
.
ar Se
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.
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 CO-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.
CHECKING THE AIR FLOW SENSOR
Disconnect the fuel distributor from the air flow sen- ;
sor, ensuring that the control plunger does not fall aut.
Extract and inspect the control plunger (avoid han-
dling the sealing surfaces). Clean the plunger in petrol,
install it-and mount the fuel distributor. Never dis-
mantle the fuel distributor any further.
CLEANING THE CONTROL PLUNGER
3. Check that the disc in the auxiliary air valve is not
sticking.
$520
CHECKING THE AUXILIARY AIR VALVE
SAAB 240-37