Page 181
Overflow valve
If the engine tends to idle too fast, the cause may bea
faulty or badly adjusted overflow valve.
OVERFLOW VALVE
1. Cap washer 8. Diaphragm
2. Adjusting screw 9. Valve
3. Rubber ring 10. Throttle
4. Cover
5. Nut
6. Spring
7. Channel to top of diaphragm
Adjusting the valve
1. Take the rubber bellows off the driver disc of the
throttle shaft.
2. a. If there is no hole in the driver disc opposite the
“cap washer (brass washer) on the overflow valve,
remove the disc and drill a hole in it approx. 1/4”
(6—8 mm) in diameter.
OVERFLOW ADJUSTMENT SCREW
Dec. 1975
b. Remove the cap washer, e.g. by drilling a hole in it
and then prying it off with a suitable tool. The
washer need not be replaced.
Refit the driver disc.
3. Turn the overflow valve adjusting screw counterclock-
wise to the limit position, i.e. until it will not turn any
farther. The valve is now held shut.
CAUTION
Do not push the screw down, as this may break the
seal so that the idling adjustment cannot be made.
4. Check and if necessary adjust the cam angle and igni-
tion setting.
5. Connect a tachometer and adjust the idling speed with
the throttle adjustment screw (800—850 rev/min,
warm engine). Stop the engine.
(If you have difficulty in getting the idling speed down
to normal, check the induction side and the vacuum
control unit of the distributor for leaks.)
6. Turn the overflow valve adjusting screw 6 full turns
clockwise.
7. Start the engine and raise the speed to 3000 rev/min
by turning the driver disc. Then release the driver disc.
If the speed then drops to the present value, the valve
is properly adjusted.
If the engine does not drop back to idling speed, turn
the adjusting screw one full turn counterclockwise
and repeat the check.
If necessary, repeat this procedure by adjusting one
full turn at a time counterclockwise until the desired
result isobtained.
If the above adjustment fails to get results, the valve must
be dismantled and checked (cleaned), and possibly ex-
changed.
Removing the overflow valve
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.
Float level
Check the float level as follows:
a. To check the level the carburetor must be removed
from the car and inverted with the float housing re-
moved,
b. If the level is correct, the highest point of the float
should project 0.67" (17 mm) and the rear edge 0.43”
(11 mm) beyond the mating surface of the carburetor
SAAB 231-9
Page 182
housing with the float valve closed. If the level is not
correct, adjust by bending the tongue of the float valve.
spindle.
NOTE
Do not bend the arm between the float and the
231-10
CARBURETOR, USA, EXPLODED VIEW, 1.7 AND 1.85 L ENGINES
. Damper screw cap
Vacuum chamber cover
Spring
. Metal washer
Plastic washer
Diaphragm
. Vacuum piston
. Fuel needie
. Float chamber plug
. O-ring
. Float chamber
. Float
|. Float valve
14.
15.
16.
17.
18.
19.
20.
21,
22.
23.
24.
25.
Carburetor housing
Throttle lever
Valve plate
Valve plate
Choke mechanism housing
Idling cam plate
Temperature compensator
Valve
Bimetal spring
Cover
Overflow valve
Air screw
Nov. 1972
Page 183
CARBURETOR
2.0 | engine
soar
CARBURETOR, 2.0 L ENGINE
Removal, dismantling, cleaning and reassembly
See carburetor 1.7 and 1.85 | engines.
Removal of overflow valve
The valve unit can be removed by undoing the three
slotted screws. When reassembling, always fit a new
gasket and scrape off all remaining traces of the old
gasket.
Float level
Follow the instructions given on pages 231—2 but note
that the tolerances here are closer: 0.630" —0.669" (16—
17 mm).
Basic setting
The vertical location of the fuel jet in relation to the
level of the jet bridge has been carefully tested in view
of the load conditions likely to be experienced. No
further adjustment of the jet screw — apart from the
adjustments described below — should be attempted.
If additional adjustment should be required, the vertical
Position of the fuel needle in the piston should be mo-
dified,
Nov. 1972
1. Remove the vacuum chamber cover together with
the spring, and the vacuum piston and diaphragm.
2. Measure the distance between the jet bridge and the
jet, using a slide gauge, and adjust to 0.089 + 0.008”
(2.5 + 0.2 mm). (If the jet is set exactly at 2.5 mm,
a quarter turn’s adjustment of the screw either way
is permissible in connection with the subsequent CO
check (1/4 turn = 0.2 mm height variation).
ADJUSTMENT OF MAIN JET
3. Check that the lower part of the track for the plastic
washer on the fuel needle is level with the underside
of the vacuum piston.
Adjust by slackening the retaining screw and moving
the needle up or down.
4. Refit the vacuum piston and diaphragm, the spring
and the vacuum chamber cover.
Adjustment of choke
Check that the distance between the adjustment screw
On the throttle shaft carrier and the choke cam disc is
0.020—0.039" (0.5—1.0 mm). Make sure that the choke
control is pushed in and that the throttle disc is com-
pletely closed.
231-11
Page 184
ADJUSTMENT OF CHOKE CONTROL
Adjustment of idling speed
Run the engine up to normal working temperature. Ad-
just the throttle shaft screw to obtain an idling speed of
850 rev/min.
ADJUSTMENT OF IDLING SPEED
Adjustment of overflow valve
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
overflow valve is closed. If there is any uncertainty
as to this point, turn the overflow valve adjustment
screw a few turns counter-clockwise.
231-12
OVERFLOW VALVE
3. Adjust the fuel quantity and engine speed to the re-
commended idling speed values. (If there is any uncer-
tainty, check ignition timing.)
4. Open the overflow valve completely by turning the
adjustment screw clockwise until the engine speed
no longer increases (approx. 1500—1800 rev/min).
5. Close the overflow valve carefully by turning the ad-
justment screw counter-clockwise until the valve just
closes. (The engine will now have returned to its nor-
mal idling speed.) Then turn the overflow 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 throt-
tle 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 overflow
valve adjustment screw should be turned slightly more
counter-clockwise.
Adjustment of CO emission
CO adjustment is carried out at an idling speed of 850
rev/min. A CO meter is required. If the carbon monoxide
value is in excess of 4.5 per cent by volume, adjust the
jet screw for a leaner mixture but not more than 1/4 of
a turn. If the adjustment is not sufficient, the vertical
position of the fuel needle in the piston must be adjusted.
SA AES Nov. 1972
Page 185
Nov. 1972
CARBURETOR, 2.0 L ENGINE
1. Damper screw cap
2. Vacuum chamber cover
3. Spring
4. Washer
5. Diaphragm
6. Vacuum piston
7. Fuel needle
8. O-ring
9. Jet retainer
10. Jet adjusting screw
11. O-ring
12. Float chamber
13, Float
14. Float valve
15. Carburetor housing
16. Carrier
S$ 3822
17. Choke mechanism with cam plate
18, Aluminum washer
19. Bushing
20. O-ring
21. Bushing
22. Spring
23. Jet
24. Overflow valve
231-13
Page 186
Carburetor, USA export model, 2.0 | engine
The engine is fitted with the same carburetor as the stan- i
dard 2.0 | engine, but the vacuum outlet is plugged. The
carburetor is not equipped with a temperature compen-
sator. See instructions under “Carburetor, 2.0 | engine”’ ¥ ‘
on page 231—11. )
+>
Page 187
FUEL PUMP, EARLIER MODEL
Removing
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.
Disassembly
1. Unscrew the cover and take out the gasket and filter.
2. Mark the flanges of the top and bottom halves of the
pump housing so that they can be reassembled later
in the same position.
3. Remove the flange screws and separate the two halves
of the housing.
4. Hold the bottom half of the housing in the hand. Push
down the diaphragm and twist it a quarter turn to the
right to disengage the diaphragm rod from the pump
lever. Remove the diaphragm rod and spring.
The top half of the pump containing the valves and the
bottom half containing the lever and manual priming
lever cannot be further disassembled.
Assembling
1, Hold the bottom half of the pump in the hand, and
insert the diaphragm with spring and rod so that the
rod slips into the slot in the lever.
2. Give the diaphragm a quarter turn to the left and check
that the rod has hooked on to the lever.
3. Push in the lever to relieve the tension on the dia-
phragm. Align the top half of the pump by the flange
markings. Insert the screws in this position and screw
the two halves together.
4. Fit a new gasket and filter. Screw on the cover.
FUEL PUMP, LATER MODEL FUEL PUMP, EARLIER MODEL
1, Cover 6. Diaphr: ing
The fuel pump cannot be dismantled and cannot be re- 2. Gasket Ss erices tale or isi
paired if there is any defect in the diaphragm or the 3. Filter 8. Lever
valves. If the pump is faulty, the whole unit must be re- 4. Top half of pump 9. Manual lever
placed. 5. Diaphragm
If the cover is removed the fuel filter can be replaced or
cleaned. The gasket should also be replaced.
FUEL PUMP, LATER MODEL
1, Cover
INSTALLING THE FUEL PUMP 2. Filter
3. Gasket
Dec, 1975 Saas 233-1
Page 188
FUEL TANK AND FUEL LINES
Removal
1. Jack up the rear end of the car.
2. Drain the tank through the drain plug (accessible from
beneath the car).
3. Take out the trunk floor covering and remove the ac-
cess panel for the fuel level transmitter. Disconnect
the wires from the transmitter. Undo all hose connec-
tions at the tank.
4. Back off the nuts on the two securing straps under the
tank.
5. Remove the tank.
REMOVING THE FUEL TANK
Installation
1. Make sure that the straps are properly mounted and
cover the filler and vent hose openings with masking
tape.
2. Clamp the wires to the top of the tank. Lift the tank
into position and suspend it in the two straps.
Center the tank and tighten the nuts. Remove the
masking tape from the filler pipe and vent hose.
4. Connect the fuel line hose and filler pipe. Make sure
that the rubber grommet is in place.
5. Connect the vent hose to the upper filler pipe. (As
from model 1970 also on top of the tank.) Connect
the wires to the fuel level transmitter and replace the
access panel. Relay the floor covering in the trunk.
6. Lower the rear end of the car.
»
234-1
Removal, Saab 99 Combi Coupé
1. Disconnect one of the battery terminals.
2. Jack up the rear of the car.
3. Drain the tank by means of the drain plug accessible
from beneath the car.
4. Remove the rear floor cover and floor panel in the
luggage compartment.
5. Disconnect the vent hoses and the filler pipe from the
tank. Plug or blank off the ends of the pipes.
6. Disconnect the fuel hose (hoses) from the pipe (pipes)
in front of the frame side member and remove the
clip from the side member. Plug the ends of the hose
(hoses) and pipe (pipes).
7. Remove the two securing strap nuts under the tank.
Lower the tank slightly and disconnect the electrical
connections from the fuel level transmitter (and the
fuel pump).
8. Remove the tank.
Installation, Saab 99 Combi Coupé
1. Check that the rubber seals on the fuel level transmitter
(and fuel pump) are in good condition and correctly
fitted.
2. Move the fuel tank roughly into position and connect
the electric cables for the fuel level transmitter (and
fuel pump).
3. Lift the tank and suspend it in the two securing straps.
4. Adjust the lateral position of the tank and then secure
it in position. Remove the plugs and masking tape.
5. Connect the fuel line (lines), filler pipe and vent hoses.
Check that the rubber grommet is in position.
6. Replace the floor panel and rear floor cover in the lug-
gage compartment.
7. Lower the car.
Dec. 1975
Page 189
Exchanging fuel lines in the passenger compartment, Removing/Installing fuel line in Passenger compartment
model 1969 Cars with injection engines
Removal See the same description as from model 1970.
1, Remove the right front seat and scuff plate protector,
Turn back the floor carpets and right wheel housing
carpet and fold up the seat cushion to expose the fuel Removing/Installing return fuel line
line. Cars with injection engines
2. Unscrew the joints in the engine compartment and
in front of the fuel tank, Unscrew the fuel line clamps See the same description for model 1969.
inside the car,
3. Pull back the forward end of the fuel line into the
Passenger compartment and bend it over to the left
of the car, Pull out the line a foot or so from under
the back seat. Straighten out the two bends under the
seat and remove the fuel line.
Installation
1. Blow down the new fuel line with compressed air.
Close the ends with masking tape.
2. Straighten the two bends at the rear end slightly and
insert the fuel line through the left-hand door under
the back seat.
3. Bend the new line to the same shape as the old one
that has been removed. Connect it to the hose from
the fuel tank and the hose in the engine compart-
ment, after removing the masking tape.
4. Make sure that the plastic clips are evenly spaced
along the line at the scuff plate, and tighten the
screw clamps.
Exchanging fuel lines in the Passenger compartment,
as from model 1970
Removal
1. Remove the left front seat and seat back cushion.
Turn back the floor carpets and left wheel housing
carpet.
. Undo the fuel line from clamps and hose connections.
. Pull the rear part of the fuel line into the Passenger
compartment and remove the line through the trunk
lid opening.
WN
Installation
1, Clean the fuel line by blowing with compressed air.
Close the ends with masking tape.
2. Insert the fuel line through the trunk lid opening and
under the seat beams into the tube Passage at dash
panel and left bearing bracket. Insert the line as far as
Possible and place the line in rear passage at the cross
member.
3. Remove the masking tape at the fuel line ends. Clamp
the line and connect the fuel hose in the engine com-
partment and the hose from the fuel tank.
4. Refit seat back cushion, the left front seat and the
Carpets.
Jan. 1972 SAAB 234-2
Page 190
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