4A•10 Fuel and exhaust systems
wiring loom lead in the engine compartment.
Also check that battery voltage is present at
one of the terminals for fuse 14. Check the
wiring if voltage is not present.
3 Remove the glovebox with reference to
Chapter 11, then remove the fuse panel
(without disconnecting the wiring) with
reference to Chapter 12.
4 Using a voltmeter, check that battery
voltage is reaching terminal 30 on the panel.
5 Check that voltage is reaching terminal 87
on the fuel pump relay. If not, check the wiring
for a fault. If all else is in good order, renew the
relay.
Trionic engine management system
6 The fuel pump relay is located in the relay
holder on the left-hand side of the facia.
Switch on the ignition, and listen for a buzzing
sound from the relay. Also listen for a buzzing
sound from the fuel pump in the fuel tank
below the rear luggage compartment.
7 If neither the relay nor the pump can be
heard, check fuse 14 in the fusebox. If this is in
order, remove the relay from the holder, and
connect an LED tester to terminals 85 and 86
in the holder. With the ignition switched on,
the tester should flash, proving that current is
reaching the relay. If current is reaching the
relay, but the pump is not running, the relay is
suspect, and a new one should be fitted.
8 If the relay can be heard to click when
current is supplied, connect a jumper lead
across fuses 14 and 22 in the f usebox. The
pump should now be receiving current. If the
pump still refuses to operate, check for current
at the pump wiring under the rear luggage
floor. If the pump is receiving current but still
refuses to operate, it must be faulty.
Renewal
9 To renew the relay, pull it direct from the
relay panel.
10 Push the new relay firmly into the relay
panel.
Note: Refer to the warning note at the end of
Section 1 before proceeding.
Removal
1 Disconnect the battery negative lead.
2 For access to the sender unit, fold the rear
seat cushions forward (where necessary).
3 Remove the luggage compartment floor
panel, then remove the cover from over the
fuel tank by turning the fasteners a quarter-
turn, using an Allen key.
4 Disconnect the wiring plugs from the fuel
gauge sender unit, noting their fitted positions.
5 The unit is secured by a screw cap. Saab
technicians use a special tool to unscrew the
cap, but a large pair of grips will achieve the
same result.
6 Withdraw the sender unit from the top of the
fuel tank, taking care not to spill fuel onto the
interior of the car. Recover the rubber sealing
ring. Check the sealing ring, and if necessary
obtain a new one.
Refitting
7 Refitting is a reversal of the removal
procedure.
Note: Refer to the warning note at the end of
Section 1 before proceeding.
Removal
1 Before removing the fuel tank, it is
preferable that all the fuel is removed from the
tank. Since a fuel tank drain plug is not
provided, carry out the removal operation
when the tank is nearly empty. If it is not
possible to syphon or hand-pump the
remaining fuel from the tank, use the following
procedure. Remove the luggage compartment
floor panel and the cover from the fuel pump,
then disconnect the wiring from the pump.
Disconnect the delivery hose from the pump,
and connect a suitable plastic tube to the
pump using a banjo union. Position the free
end of the plastic tube in a suitable container.
Remove fuses 14 and 22 from the f usebox
with reference to Chapter 12, then connect a
bridging wire between the two terminals to
start the fuel pump. Pump all of the fuel out of
the tank, then reconnect all components. Keep
the fuel in a safe place, observing the
precautions given in Section 1.
2 Disconnect the battery negative lead.
3 Remove the rear luggage compartment floor
panels, and the cover from the fuel pump
(using an Allen key).
4 Disconnect the fuel lines and wiring from the
fuel pump.
5 Chock the front wheels, then jack up the
rear of the car and support on axle stands (see
"Jacking, towing and wheel changing"). Make
sure that the stands will not obstruct the
removal of the tank. Remove the right-hand
rear wheel.
6 Loosen the clips and disconnect the inlet
hose from the tank. Also disconnect the
breather hose.
7 Working beneath the car, detach the
handbrake cable (refer to Chapter 9).
8 Support the weight of the fuel tank using a
trolley jack with an interposed block of wood,
then unscrew the tank mounting nuts. Start
with the right-hand mounting, so that the
handbrake cable can be tied to one side.
Remove both mounting straps.
9 With the help of an assistant, lower the fuel
tank and remove it from under the car.
10 If the tank is contaminated with sediment
or water, remove the sender unit (models with
LH-Jetronic fuel injection - Section 12) and
swill the tank out with clean fuel. In certain
cases, it may be possible to have small leaks
or minor damage repaired. Seek the advice of
a suitable specialist before attempting to
repair the fuel tank.
Refitting
11 Refitting is the reverse of the removal
procedure, noting the following points:
a) When lifting the tank back into position,
make sure that the mounting straps are
correctly positioned, and take great care
to ensure that none of the hoses become
trapped between the tank and vehicle
body.
b) Ensure that all pipes and hoses are
correctly routed, and securely held in
position with their retaining clips.
c) When refitting the anti-splash device,
make sure that the butterfly spindle is
vertical.
d) On completion, refill the tank with fuel,
and check for signs of leakage prior to
taking the vehicle out on the road.
Testing
1 If a fault appears in the fuel injection system,
first ensure that all the system wiring
connectors are securely connected and free of
corrosion. Then ensure that the fault is not due
to poor maintenance - ie, check that the air
cleaner filter element is clean, the spark plugs
are in good condition and correctly gapped,
the cylinder compression pressures are
correct, the ignition timing is correct (where
this is adjustable), and that the engine
breather hoses are clear and undamaged,
referring to Chapters 1, 2 and 5 for further
information.
2 If these checks fail to reveal the cause of the
problem, the car should be taken to a Saab
dealer for testing. A diagnostic connector is
incorporated in the wiring circuit, into which a
Saab special electronic diagnostic tester can
be plugged. The tester will locate the fault
quickly and simply, alleviating the need to test
all the system components individually.
Checking and adjustment
3 The following adjustments are only
possible on certain models fitted with the
LH-Jetronic fuel injection system. The idle
speed may be adjusted on engines not fitted
with idle control, and the idle mixture may be
adjusted on engines not fitted with a catalytic
converter. On models with the Trionic engine
management system, the idle speed and
mixture are automatically controlled by the
ECU. The checking of idle speed and mixture
is possible on all models by using a
tachometer and exhaust gas analyser, but
some difficulty may be experienced
connecting a conventional tachometer to the
engine on cars fitted with Direct Ignition. Most