Saab 1987 900 Owner's Manual page 68

66 Car care and scheduled maintenance
NOTEl The original equipment road
wheels are designed to be mounted using
nuts with a conical seating surface.
These nuts are suitable for mounting the
compact spare. Certain accessory wheels
available from Saab dealers require spe-
cial shouldered nuts which do not fit the
spare wheel. Obtain four conical nuts for
the spare if the car is to be so equipped
and keep them in the tool kit.
Engine troubleshooting
1. Engine will not start - starter cranks
engine in normal manner.
A.
No fuel in tank.
B. Fuel pump not running - blown fuse,
corroded connection, faulty relays or
disconnected lead wire.
C. No spark at spark plugs.
a. loose electrical connections.
b. Moisture or cracks in distributor cap.
D. Engine flooded - spark plugs fouled
with gasoline.
E . Check fuses.
2. Engine starts - runs rough, misfires,
low power.
NOTEl Misfiring should be corrected
immediately to prevent overheating of
the catalytic converter.
A.
Spark plugs fouled, worn or in need of
adjustment.
B. Spark plug cables not properly plugged
into distributor cap or onto spark plugs.
C. Loose or corroded connections - low vol-
tage leads to coil.
D. Engine oil filler cap or dipstick not sea-
ted admitting excess air through crank-
case vent system.
E. Fuel iqjection system in need of adjust-
ment.
3. Stalling at idle, rough operation
during engine warm-up and hesita-
tion or lack of power on accelera-
tion.
A.
Unscheduled servicing of the Lambda
control system may be necessary or the
throttle switch may be out of adjust-
ment. If so, this should be performed by
a Saab dealer.
B. Decel fuel shut off system may require
unscheduled servicing. (8 valve, manual
transmission)
4. Improper idle speed - too fast or too
slow.
A. Idle speed air bleed/automatic idle cont-
rol adjustment incorrect or lock nut
loose.
B. Decel dashpot out of adjustment (fast
idle). Not applicable to 8 valve, manual
transmission cars.
C. Idle air/fuel mixture out of specification.
D. Throttle stop screw incorrectly set.
E. Decel fuel shut off malfunctioning. (8
valve, manual only)
F. Idle speed is affected by large changes in
altitude (idle decreases as elevation
increases due to reduced ambient pres-
sure and vice versa).
5. Charge indicator lamp fails to light
when ignition is switched on.
A.
Bulb burned out.
B. Discharged battery or loose battery
cable.
C. Improper wiring to voltage regulator
causing an open circuit.
D. Check fuses.