Page 181
DECELERATION VALVE, MODEL 1977
(SWEDEN-VERSION AS FROM MODEL
197
USA-VERSION AS FROM MODEL 1970) ies
Removal and installation
1. Remove the carburetor,
2. Disconnect the crankcase ventilation hose and remove
the intermediate flange with the deceleration valve
REMOVAL OF DECELERATION VALVE
3. Unscrew the valve from the angle nipple (only if the
valve is to be exchanged).
Installation is carried out in the reverse order.
Dismantling and assembling
1. Remove the bottom cover retaining bolt and remove
the cover, diaphragm and spring.
Febr 1977
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DECELERATION VALVE WITH BOTTOM COVER REMOVED
2. Undo the top cover retaining bolts and remove the
cover complete with adjusting screw, gasket, spring
and spring seat and valve.
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DECELERATION VALVE TOP COVER REMOVED
231—17
Page 182
DECELERATION VALVE
. Adjusting screw
. Gasket
. Spring
Vaive
Body
Spring
Diaphragm
Bottom cover
. Intermediate flange
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Assembly is carried out in the reverse order.
Setting
Checking
NOTE
The air cleaner must be fitted.
1. Run the engine until normal operating temperature.
2. Check that the deceleration valve is not working at
idling speed. This can be done by disconnecting one
of the hoses between carburetor and deceleration valve.
231—18
If the valve is open, i.e. vacuum Is passing the valve,
the adjusting screw on the deceleration valve has to
be screwed further in until the valve is closed. Con-
nect the hose.
If the deceleration valve is working at idling speed,
you will get a very fast idle (1 200—1 400 r/min). It
is not possible to adjust this in a normal way.
3. Connect a tachometer and adjust the idling speed in
accordance with the specifications in group O.
4. Advance the engine speed to 3 000 r/min with the
throttle. Let down the throttle rapidly and measure
the time as require to drop the engine speed from
3 000 r/min to idle.
An engine fitted with a correctly adjusted decelera-
tion valve should drop from 3 000 r/min to idle in
4 to 6 seconds. (USA-version as from model 1970
7 to 8 seconds.)
Adjustment
1. Remove the air cleaner.
2. a. If the requisite time from 3 000 r/min to 900 r/min
is more than the prescribed, the deceleration valve
adjusting screw should be screwed clockwise until
the desired figure is reached.
b. If the requisite time is less than the prescribed, the
adjusting screw should be screwed anti-clockwise
until the desired figure is reached.
ADJUSTING THE DECELERATION VALVE
3. Fit the air cleaner and check the requisite time again.
if necessary, repeat the procedure until the requisite
time is correct.
Failure of the diaphragm will allow air to pass from the
bleed hole in the cover, through the diaphragm and
straight into the inlet manifold. Normal adjustment of
idling speed is not possible. Replace the diaphragm if
combustion exhaust emission control is demanded. If
not, just cover up the bleed hole in the cover.
Febr 1977
Page 183
Carburetor, make Solex. as fr
1977 B om Model
REMOVAL
_ Remove the air cleaner.
Disconnect the coolant hoses from the autom
Disconnect the throttle from the carburetor
Disconnect the fuel and vacuum hoses. ;
Remove the carburetor,
Blank off the end of the suction pipe,
atic choke.
Omfrwnr —
DISMANTLING
REMOVING TOP SECTION OF CARBURETOR
1, Remove the bolts securing the top section to the
carburetor housing. Lift off the top section and
undo the linkage between the throttle valve lever
and the automatic choke mechanism.
m6 7 8 10 11 12
13. N «ose a
e nS pane 25.26 27 28
15 16 17 18 19 20, 21 22 23
21. Throttle valve
CARBURETOR ee caus 21.7 oe
1. Air jet, main system — , . Mixture adjusting screw, idling
2. Vedios ibe float chamber ventilation rn Fassett 23. Idling adjusting screw
3. Air jet, transition system 14. Air passage, transition system 24. Vacuum passage
4. Fuel jet, transition system 15. Throat ring 25. Idling jet -
5. Air jet, main system 16. Throttle valve = eal a i be es
6. Choke valve 17, Emulsion pipe - : a sth vatihabee og choke
7. Air passage, idling system 18. Main jet . ,
8. Vacuum passage 19, Emulsion pipe
20, Main jet
9. Step cam, fast idling
10. Driver
231-19
Feby 1095
Page 184
2. Remove the float lever spindle and remove the float.
VING ACCELERATION JET
REMO
8. Remove the acceleration pump cover retaining bolts
and disconnect the linkage between the accelera-
REMOVING FLOAT SPINDLE tion pump and the throttle valve lever. Remove the
spring and diaphragm.
9. Remove the bolts securing the throttle valve sec-
tion to the carburetor housing.
Remove the circlip from the push rod for the float
chamber ventilation and remove the push rod and
4. Remove the bi-metallic spring housing retaining j
springs.
screws.
3. Remove the float retaining spring and unscrew the 10
float valve. :
11. Remove the lever for the float chamber ventilation.
5. Remove the cover retaining bolts from the vacuum :
control unit for the choke valve. Remove the cover, bl
spring and diaphragm with thrust rod. Assembly
Clean the carburetor and flush all passages and fixed jets
with compressed air. On reassembly, fit new gaskets and
seals in the carburetor.
1. Connect the levers, springs and washers to the throt-
tle spindle. Fit them in the order shown in the illus-
tration. The throttle adjusting screw for the secon-
dary stage has been preset at the factory and this
setting must not be altered.
REMOVING VACUUM CONTROL COVER
6. Remove the bolts securing the choke housing to
the carburetor. Do not neglect the O-ring at the IN
vacuum passage. STALLATION POSITION FOR THE WASHERS
7. Unscrew the jets for the main system and transition
system, and remove the idling jet and full-load
booster valve. Use a special screwdriver for the
booster valve. Use a small screwdriver to carefully
lever free the injection jet for the acceleration system,
231-20 SAAB
Nov 1977
Page 185
ee
%
10.
Fit the lever for the float chamber ventilation.
From above, fit the push rod for the float chamber
ventilation in the carburetor, with the soft spring.
Then fit the stiffer spring and connect the push rod
to the lever.
Bolt the throttle valve section to the carburetor
housing. Use a new gasket.
Connect the control linkage for the acceleration
pump system to the throttle valve lever and install
the acceleration pump with spring and diaphragm.
Insert a new O-ring in the spray pipe for the acce-
leration system and insert the spray pipe in the car-
buretor housing. Screw in the jets for the main sys-
tem and transition system and install the idling jet
and booster valve. The various jets in the primary
and secondary stages are of different sizes. Refer
to the jet specifications in section 020 to ensure
that the jets are fitted in the correct positions.
Bolt the choke housing to the carburetor housing.
Note the O-ring for the vacuum passage.
Fit the vacuum control for the choke valve.
Screw in the float valve and fit the float retaining
spring.
Install the float. Note the position of the float re-
taining spring. Check the level of the float (refer
to section ‘Checking and adjusting the float level’’).
gave
FLOAT RETAINING SPRING
11.
12,
Connect the control linkage between the throttle
valve lever and the automatic choke. Fit a new gas-
ket on the carburetor housing and bolt on the top
section of the carburetor.
Fit the bi-metallic spring housing so that the driver
arm on the choke spindle is in line above the lug on
the bi-metallic spring.
FITTING BI-METALL HOUSING
13. Twist the bi-metallic spring housing until the instal-
lation marks coincide and then secure the housing.
INSTALLATION MARK, AUTOMATIC CHOKE
14. Check the functioning of the throttle and choke
valves, and the automatic choke, acceleration pump
and float chamber ventilation.
REFITTING
Refit the carburetor in the reverse order. Fit the carbu-
retor with a new gasket.
SAAB 231-21
LY
Page 186
CHECKING AND ADJUSTING OF FLOAT LEVEL
Remove the top section of the carburetor if this has not
already been done. Twist the top section to an angle of
45° to the horizontal.
Note! Do not depress the ball at the end of the float
valve while measuring. Any adjustments should be made
by bending the float lever,
There are two different types of floats.
Carburetor design 77 TF—9510-SA:
0.67—0.75 in. INTERNAL VENTILATION
(17-19 mm)
$7079
Using a vernier gauge, measure the distance between the
upper flat part of the carburetor and the upper flange
of the float. The distance shall be 0.67—0.75 in. (17—
19 mm) and equal on both sides.
Carburetor design 79 TF—9510—LA:
FLOAT CHAMBER VENTILATION
The distance between the lowest part of the float (in
normal position) and the flat surface of the carburetor
cover shall be 1.65—1.73 in. (42—44 mm).
CHECKING AND ADJUSTING OF FLOAT CHAMBER
VENTILATION
Operation of the float chamber ventilation is controlled
by the throttle valve lever. Check the ventilation, there-
fore, after the idling speed has been set. The valve moves
by means of two springs of different strengths. With the
throttle closed, the distance between the lower washer
on the push rod and the lever should be 0.01—-0.03 in.
(0.4—0.7 mm), Make any adjustments by bending the
lever for the float chamber ventilation against the throt-
tle valve lever.
231-22 SAAB
March 1979
Page 187
CHECKING AND ADJUSTING OF VACUUM CONTROL
(PULL-DOWN) OF CHOKE VALVE
Remove the bi-metallic spring housing. Press up the diaph-
ragm rod for the vacuum control and hold it in this posi-
tion. Turn the primary choke valve towards the closed
position until obvious resistance is felt, By means of a
drill, measure the distance between the upper edge of the
choke valve disc and the carburetor housing. The distance
should be 0.13 + 0.007 in. (3.3 + 0.2 mm). Make any ad-
justments by means of the adjusting screw above the dia-
phragm chamber.
CHECKING THE VACUUM CONTROL, CHOKE VALVE
1. Adjustment screw
SETTING THE AUTOMATIC CHOKE
The installation line on the rotatable bi-metallic spring
housing should concide with the central mark of the five.
The bi-metallic spring is then set so that the choke will
open completely when the temperature of the coolant
exceeds 178—187°F (60—65°C). Rotation clockwise
away from the basic setting will cause the choke to open
later.
It is essential that the choke valve spindles move freely,
if the automatic choke is to operate correctly.
Noy 1977
INSTALLATION MARK, AUTOMATIC CHOKE
CHECKING AND SETTING THE FAST IDLING SPEED
Start the checking with the engine warm at a standstill.
Turn the throttle lever so that the choke valve can be
closed completely. Then, first release the throttle lever
and then the choke valve. This procedure sets the throt-
tle valve in the fast idling position without the aid of the
bi-metallic spring.
Note! Do not now move either the throttle control or
the accelerator.
Start the engine and check the fast idling speed which
should be 3 OOO—3 200 rev/min. Make any necessary ad-
justment by backing off the screw in the dual lever pro-
jecting from the choke housing, whereupon the relative
position of the lever sections can be adjusted.
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FAST IDLING ADJUSTING SCREW
231—23
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Page 188
ADJUSTING THE IDLING SPEED AND CO-SETTING
Checking and adjusting should be made with the engine
warm, the headlamps switched to low beam and within
five minutes of the time that the thermostat opens. De-
pending on the mileage on the speedometer, check the
breaker points, spark plugs, timing and valve clearance
before attempting to adjust the idling speed and CO-set-
ting.
1, Remove the air cleaner.
2. Remove the seal on the mixture adjusting screw.
3. By means of the idling adjusting screw, set the engine
speed to 875 + 20 rev/min.
4. When necessary, use the mixture adjusting screw to
achieve the correct setting (1 + 0.5 %).
b. Fit a new plastic plug (for sealing) to the mixture ad-
justing screw.
ADJUSTING SCREWS
1. Idling setting screw
2. Mixture adjusting screw
231-24
OF THROTTLE VALVE
CHECKING AND ADJUSTING
DAMPER
e valve damper is designed to delay the return
tle valve during engine overrun. Checking and
ried out with the engine warm and with
nd idling speed correctly adjusted.
turn to idling speed from 3 000
/min should be between 4 and 6 seconds. Make any
rev/min djustment by removing the retaining nuts,
aoe pat damper can be moved towards or away
ttle valve lever.
the stop on the thro re
tre the damper towards the stop will increase the
delay time.
The thrott!
of the throt
adjusting are car
the CO-setting 4
The time taken to re
ADJUSTING THE THROTTLE VALVE DAMPER
Nov 1977
Page 189
_
AIR CLEANER
THERMOSTATICALLY REGULATED
HEATER AIR PRE:
(Sweden-version model 1976 and 1977, USA- i
from model 1970) ‘ version as
A thermostatically controlled valve device js mounted at
the air cleaner intake and this is designed to ensure that
the intake air maintains a constant temperature of around
86°F (30°C). There are two air intakes, one for cold air
and one for heated air. The cold air intake points for-
ward while the preheated air js supplied by a hose con-
nected to a box mounted on the exhaust pipe.
THERMOSTATICALLY CONTROLED AIR PREHEATER
1, Carburetor
2. Deceleration valve
3. Thermostatically controled valve
Febr 1977
Checking
To carry out the following check, disconnect the cold air
intake from the valve assembly and observe the position
of the valve.
1. With the engine switched off and cold, and an am-
bient temperature of less than 68°F (25°C), the valve
should shut off the cold air intake.
2. When the engine is running and the ambient air tem-
perature is less than 86°F (30°C), the valve should be
in the intermediate position, allowing cold and warm
air to mix to a suitable temperature. At very low tem-
peratures, the cold air intake will be shut off complete-
ly. When the ambient temperature exceeds 86°F (30°C), i
the warm air supply will be completely shut off.
Checking dismantled valve assembly
Sweden-version, model 1976 and 1977
1, Remove the air preheater from the air cleaner.
2. Place the flap valve under running water with a tem-
perature of 68°F (25°C). The flap valve will now
shut the cold air intake.
3. Raise the water temperature to 95°F (35°C). The
flap valve will now shut the warm air intake.
é
‘
CHECKING A DISMANTLED AIR PREHEATER
232-1
Page 190
1. Place the flap valve under running water with a tem-
perature of 82—85°F (28—30°Cc).
Note! The valve should be kept at an angle of 15°
against the manouvre rod to give the thermostat
strength to move the valve.
USA-version, as from model 1970
|
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| i
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THE FLAP VALVE HAS MOVED TO ITS LEFT POSITION
If these requirements are not met the thermostatic unit
should be replaced.
HOLDING THE FLAP VALVE IN POSITION
2. Let go the flap valve a minute, and it will remain in
the same position.
3. Let the temperature of the water rise to 87—90°F
(31—32°C). The flap valve will now move to the
central position.
THE FLAP VALVE HAS MOVED TO ITS CENTRAL POSITION
4. When the temperature of the water is 95-1059F
(35—40°C), the flap valve has moved to its left posi-
tion.
232-2 SAAB
Febr 1977