Page 191
ADJUSTING SCREWS
ADJUSTING SCREWS
1. Vent valve, float chamber, front carburetor
2. Synchronizing the throttle valve.
3. Idling setting.
4. Vent valve, float chamber, rear carburetor.
1. Vent valve, float chamber, front carburetor
The setting is fixed and adjustment is not normally
necessary. In the event of any adjustment being made,
this will affect the settings of adjusting screws 2, 3 and
4. These must therefore be readjusted in the given
order.
2. Synchronizing the throttle valve
This is carried out in conjunction with checking the
idling speed and CO-setting. Any adjustment will affect the settings of adjusting screws 3 and 4, which
must also subsequently be readjusted in the given
order.
3. Idling setting
If any adjustment is made it will affect the setting of
adjusting screw 4, which should also be checked.
4. Vent valve, float chamber, rear carburetor
This should be checked if any of the adjusting screws
1, 2 or 3 have been moved.
SA.4'B
231-21
Page 192
Single- and twin-carburetor
Adjustment
TEMPERATURE
COMPENSATOR
Back off the bi-metallic strip retaining screw slightly and
centre the valve by pressing it towards its seating and
then tighten the screw.
The temperature compensator serves to maintain a constant fuel-air mixture, regardless of engine temperature.
The temperature compensator valve is governed by a
bi-metallic strip which, on heating, opens an air passage
past the vacuum piston. The valve opens at around 50°F
(+10°C).
Setting
At 68°F (+20°C) the valve should have opened
0.004-0.012 in. (0.1-0.3 mm). To check the setting,
the temperature compensator should be removed from
the carburetor and kept at a temperature of 68°F(+200C) until it has acquired this temperature. Setting
is by means of the bi-metallic strip adjusting nut.
TEMPERATURE COMPENSATOR
----------
7
6
2
6
CHECKING THE SETTING OF THE TEMPERATURE
COMPENSATOR
5
3
4
S 4961
Changing
TEMPERATURE COMPENSATOR
1. Air passage
2. Valve
3. Bi-metallic strip
4. Adjusting nut
5. Bi-metallic strip retaining screw
6. Seal
7. Jet bridge
Change the temperature compensator as a complete unit.
To remove it, undo the two slotted screws.
In the event of the idling speed dropping rapidly when
the engine is idling and particularly in warm weather,
check the operation of the temperature compensator by
removing the plastic cover and pressing the valve, whereupon the idling should become less smooth. If the valve is
stiff or sticks it can be adjusted. This is on the condition
that it is not scratched or coated. Should this prove to
be the case, it should be completely renewed.
SAAB
231-22
--
--
NOTE
Both the outer and inner rubber gaskets must be exchanged.
.
,
Page 193
DECELERATION VALVE
The function of the deceleration valve is to improve combustion during engine overrun. The valve, which is a diaphragm valve, is opened as a result of the vacuum in the
inlet duct. This ensures that the fuel-air mixture is correctly maintained to allow satisfactory combustion during
engine overrun.
If the engine tends to idle too fast, the cause may be a
faulty or badly adjusted deceleration valve.
1
2
ADJUSTING THE DECELERATION
VALVE
Tool 83 92 748 or 83 92 953.
3
4
5
3. Adjust the fuel quantity and engine speed to the recommended idling speed values. (If there is any uncertainty, check ignition timing.)
4. Open the deceleration valve completely by turning the
adjustment screw clockwise until the engine speed no
longer increases {approx. 1500-1800 rev/min.).
5. Close the deceleration valve carefully by turning the
adjustment screw counter-clockwise until the valve
just closes. (The engine will now have returned to its
normal idling speed.) Then turn the deceleration adjustment screw an additional one-half to three-quarters
of a turn counter-clockwise.
6. Check the above adjustments by racing the engine up
to approx. 3000 rev/min and then releasing the throttle control to idling position again. The engine should
return to a normal idling speed although there will be
some slight delay. If this is not the case, the deceleration valve adjustment screw should be turned slightly
more counter-clockwise.
6
7
8
S4410
DELECERATION
1. Adjusting screw
2. Rubber ring
3. Cover
4. Nut
5. Spring
VALVE
6. Channel to top of diaphragm
7. Diaphragm
8. Valve
9. Throttle
Adjustment
Removing and reassembling
1. Run the engine and the carburetor up to working temperature. Note that the air preheater must be in the appropriate position for the time of year.
2. Run the engine at idling speed and check that the deceleration valve is closed. If there is any uncertainty
as to this point, turn the deceleration valve adjustment screw a few turns counter-clockwise.
To remove the valve unit, undo the three slotted screws.
When reassembling, scrape any remaining fragments of
gasket off the mating surfaces and always fit a new gasket.
SAAB
231-23
Page 194
VALVE FOR FLOAT CHAMBER VENTILATION
a. When the throttle valve is fully closed, it should
not be possible to blow through the nipple (since
the float chamber is an enclosed space).
Checking and setting
The valve should be set so that air is drawn in from the
outside when the throttle valve is closed (idling setting).
When the throttle valve opens, ventilation should be
supplied through the connection on the air cleaner.
1
S 5620
1
THROTTLE
VALVE
1. Ventilation
2. Ventilation
from air cleaner
from outside
FULLY CLOSED
b. If the throttle is opened between 0.5-1.0 mm (by
means of cable on carrier), a passage will open to
the inner ventilation, making it possible to blow
through the nipple.
2
1
VALVE
FOR FLOAT CHAMBER VENTILATION
1. Ventilation
2. Ventilation
through air cleaner
from outside.
1. Connect a hose to the opening of the pipe for the outside ventilation.
2. Blow through the hose. If the fuel line is not fitted
and connected to the pump, the fuel inlet nipple must
be blanked off.
S 5621
THROTTLE
VALVE OPEN BETWEEN 0.5-1.0
MM
c. If the throttle valve is opened a few more millimetres, the connection should close again.
1
S 5622
CHECKING VENTILATION
231-24
FROM OUTSIDE
THROTTLE
VALVE OPEN A FEW MORE MILLIMETRES
Page 195
3. Undo the lock nut and adjust the flap regulating the
valve. Adjust by means of the adjusting screw as described in 2a and 2b.
CHOKE CONTROL
Removing
1. Undo the control cable and its sheath from the carbu-
retor. Note how the cable is fitted. Free the cable in
the engine compartment.
2. Remove the left-hand sheet below the instrument
panel.
3. Remove the control button and remove the transparent plastic washer from above the warning light.
4. Unscrew the eye nut which holds the control onto the
instrument panel and disconnect the warning light
cable from the control contact.
5. Pull the control cable out of the grommet in the dash
penel.
Installing
ADJUSTING SINGLE-CARBURETOR
CARBURETOR
AND FRONT TWIN-
1. Check that the grommet is correctly positioned in the
dash panel. Feed in the control cable, so that it can be
fitted to the instrument panel.
2. Connect the warning-light cable to the control contact.
3. Fit the control to the instrument panel, fit the plastic
washer above the warning light and screw on the button.
4. Refit the cable as far as the carburetor.
5. Fit the cable to the carburetor and adjust in accordance
with "Choke control, adjustment"
6. Replace the panel under the instrument panel.
ADJUSTING REAR TWIN-CARBURETOR USING SPECIAL
SPANNER FOR LOCK NUT (1/4 IN. ACROSS FLATS)
4. Following the above adjustments, the idling speed,
CO-setting and synchronization (twin-carbs.) must be
checked and adjusted.
SAAB
231-25
Page 196
AIR CLEANER
Thermostatically controlled air preheating, as from
model 1978
THERMOSTATICALLY
CONTROLLED
AS FROM MODEL 1978
AIR PREHEATING,
CHECKING THE THERMOSTAT
Checking
A rough check of the operation of the valve is possible
by comparison with the ambient air temperature:
At temperatures below +43°F (+S°C) (Saab 99Turbo
+23°F (-5°C)), only heated air is inducted into the
engine.
At temperatures between +43°F (+S°C) and +64°F
(+1S°C) (Saab 99 Turbo +23°F (-5°C) and +41°F
(+5°C)), the valve admits varying proportions of heated and cold air.
At temperatures above 64°F (+ 1s0 c) (Saab 99 Turbo
+41 °F (+ 5°C)), only cold air is inducted.
A more accurate check can be made by submering the
thermostat body in warm water (glycol/water mixture)
and checking that the valve operates.
232-1
SAAB
Page 197
FUEL PUMP
REMOVING AND REASSEMBLING
Pull the fuel line hose off the pump. Remove the retaining
screws and washers, unship the pump and remove the old
gasket. Always use a new gasket when reassembling.
The fuel pump cannot be dismantled and cannot be repaired if there is any defect in the diaphragm or the valves. If the pump is faulty, the whole unit must be replaced.
If the cover is removed the fuel filter can be replaced or
cleaned. The gasket should also be replaced.
FUEL PUMP
1. Cover
2. Filter
3. Gasket
233-1
Page 199
FUEL TANK AND FUEL LINES
4. Saab 99 (99 L), 99 L (99 GL) and 99 EMS: Remove
the carpet in the trunk compartment.
Saab 99 Combi Coupe: Remove the rear floor panel in
the luggage compartment.
5. Remove the fuel level transmitter cover plate.
6. Remove all electrical connections from the tank.
7. Remove the filler pipe and ventilation hoses from the
fuel pump.
Cars with carbureted engines: Disconnect the fuel line
from the tank.
Cars with injection engines: Disconnect the pressure
and return fuel lines from the fuel accumulator and
the tank. Remove the fuel line clips.
8. Remove the securing strap nuts under the tank.
9. Lower the tank.
Installing
S 7515
RUBBER SEALINGS
1. Check that the rubber seals are undamaged and that
they are correctly fitted round the opening of the fuel
level transmitter (fuel pump).
2. Check that the straps are properly mounted, and cover the filler and vent hose openings with masking tape.
3. Clamp the wires to the top of the tank. Lift the tank
into position and suspend it in the two straps.
4. Center the tank and tighten the nuts. Remove the
masking tape from the filler pipe and vent hose.
5. Connect the fuel line(s) and the hose to the filler pipe.
Make sure that the rubber grommet is in place.
6. Connect the vent hoses to the upper filler pipe and to
the top of the tank. Connect the wires to the fuel level transmitter (fuel pump) and replace the accesspanel. Relay the floor covering in the trunk.
Saab 99 (99 L), 99 L (99 GL) and 99 EMS: Replace
the carpet in the trunk compartment.
Saab 99 Combi Coupe: Replace the floor panel and
rear floor cover in the luggage compartment.
7. Lower the rear end of the car.
8. Connect the battery earth cable.
FUEL TANK
Removing
1. Disconnect the earth cable from the battery.
2. Jack up the rear end of the car.
3. Drain the fuel tank. To prevent unnecessary emission
of hydrocarbons into the wo.rkshop, drain the tank by
means of a closed system.
Cars with carburetor engines: Connect an electric fuel
pump (designed for injection engines) to the inlet line
of the-fuel tank and pump the fuel through a hose into
a container. The work should be done with the car
jacked up.
Cars with injection engines: Disconnect the fuel line
from the fuel pump and connect a special line with a
banjo connection, with the other end connected to a
container.
The container should be enclosed and equipped with
a vent hose which should be run back into the fuel
filler pipe.
FUEL PIPES
RUNNING THE FUEL PIPES
Fuel pipes should not come into contact with any object
that could result in wear through chafing.
The risk of wear from chafing is particularly great from
contact with plastic components subjected to engine vibrations (e.g. other fuel pipes, dip stick sleeve, throttle
cable, the lower section of the mixture control unit, etc.).
It is therefore of special importance when working in the
engine compartment that all fuel pipes are run clear of
such equipment. Sheath the pipes with PVC sleeves if
contact is unadvoidable.
EMPTYING THE FUEL TANK BY MEANS OF AN ELECTRIC
FUEL PUMP
SA1'11
.L
"'I\
234-1
Page 200
Checking fuel pipes (every 5,000 miles (10,000 km) or
10,000 miles (15,000 km)
REPLACING FUEL LINES IN THE PASSENGER
COMPARTMENT
Follow the pipes and check to see if there is any evidence
of wear through chafing.
Special care should be taken when checking pipes that
intersect or are run near plastic components.
The fuel line (fuel lines in cars with ir;ection engines)
from the tank to the engine compartment runs through
the passenger compartment along the left-hand sill beam.
In model 1975, cars with injection engines, the return
fuel line runs along the right-hand sill beam.
Removal
1. Remove the kick plate and turn back the carpet from
Pipe wall thickness, fuel pipes:
Pipes to injection valves
Other pipes
-2mm
-1mm
Re-route the pipes and fit PVC sleeves if chafing is detected. If the wear is greater than half of the thickness of the
pipe wall then the fuel pipe should be replaced.
Checking pipe connections (every 10,000 m. (15,000 km))
Check if banjo connections are leaking.
The seals should be replaced every time the connections
are loosened.
the sill beam.
2. Remove the tape holding the fuel line.
3. Remove the insulation felt from the dash panel.
4. Disconnect the fuel line in the engine compartment,
remove the rubber grommet and pull the line into the
passenger compartment.
Cars with carbureted engines: Disconnect the connection at the fuel pump.
Cars with injection engines:
On the 1975 model, remove the return fuel line from
the joint at the right hand side spring link bracket. As
from model 1976, remove the return fuel line from
the fuel distributor. Remove the pressure line from
the fuel filter.
In model 1975 and early 1976 model cars, the holes
in the bulkhead and spring link bracket are too small
for the banjo nipple on the fuel line. The nipple must
therefore be removed before the line can be withdrawn (see under "Removing and fitting the fuel line
nipple").
5. Model 1975:
Lift the rear seat cushion, disconnect the angle connecting piece (pieces) at the point where it passes
through the body, and remove the fuel line (lines).
As from model 1976:
Undo the clip and disconnect the fuel line from the
fuel tank. In cars with injection engines, disconnect
the fuel Hne from the fuel accumulator and from the
fuel tank.
Installation
1. Clean the fuel line by blowing through with compressed air. Close the ends with masking tape.
2. Push the fuel .line through the hole in the dash panel
and the spring link bracket and connect the line in the
engine compartment.
.
·1n model 1975 and early 1976 model cars, the banjo
nipple should be fitted to the fuel line after the line
has been inserted through the bulkhead and the spring
link bracket (see under "Removing and fitting the.fuel
.
.
line nipple"). .
3. Insert the rubber grommets -irithe hoie_in the da_sh
panel and in the front hole in the spring link bracket.
4. Push the fuel line into position and connect it at_the
rear where it passes through the body. Secure the line
with tape in two places along the sill beam. _
5. Fit the insulation felt on the dash panel. Replace the
carpet and kick plate .
234-2
....