Page 171
Fuel Injection
87681-S2l1356
240-25
Fig. 33. Meter leads connected to idle control valve terminals 2 and 3
(valve terminal 4 and 5).
Fig. 31. Jumper terminals 1 (gray wire) and 2 (black-white wire) of
throttle position sensor connector. Connect wire from back of
connector to prevent damage to terminals.
NOTE
Make sure all other electrical accessories on the car are off.
Make all adjustments to idle only when the fan is off.
3. Loosen the throttle stop screw locknut and back out the
screw until it is no longer contacting the throttle lever.
See Fig. 32. Thread the screw in until it touches the lever then turn it an additional 3/4 turn. Tighten the locknut.
6. Depending on the throttle housing, turn either the throttle valve stop screw (Fig. 32) or the throttle valve air
bleed screw (Fig. 34) out until the duty cycle is 38%
(34 0 dwell).
NOTE
If the correct reading cannot be obtained, check for intake air
leaks or other engine problems.
87682-S2l1175
Fig. 32. Throttle stop screw and locknut (arrow).
4. Working from the rear of the AIC valve's harness connector, connect the dwell meter to terminals 2 and 3.
See Fig. 33. Connect the tachometer.
5. Start the engine and let it run until the radiator fan cycles at least once.
Fig. 34. Throttle valve air bleed screw (arrow) used on early models.
Later models with LH 2.2 do not have this screw.
LH FUEL INJECT/ON ADJUSTMENTS
Page 172
240-26
Fuel Injection
7. Next, turn the screw back in until the meter reading is
as specified in the table below.
NOTE
3. Rotate the switch so that the switch is just open (no
continuity), then rotate the switch in the opposite direction until the switch just closes (continuity). Rotate the
switch a bit further (approximately.5 mm/.020 in.) in the
same direction and tighten the screws.
When the correct reading is obtained, the base idle speed
should be 850±50 rpm. If it isn't, check for intake air leaks or
other engine problems.
NOTE
Rotation of the throttle position sensor too far can cause the
switch to hold the throttle open. This may lead to excessive
idle speed.
Base Idle Speed (at 850±50 rpm)
• Duty cycle
• Dwell
33%
30°
8. Lock the adjusting screw and recheck the reading.
9. Turn off the engine and remove all test equipment. Reset the dashpot and throttle switch as described below
To adjust throttle position sensor (LH 2.2 and
LH 2.4)
The th rottle position sensor has two switches in the housing
that provide a ground signal whenever the throttle is fully
closed or fully open.
1. Loosen the switch mounting screws.
2. Attach a VOM to terminals 1 and 2 of the switch to measure continuity. See Fig. 35.
4. Check that the switch opens (no continuity) as the
throttle is just opened from idle.
5. Connect the ohmmeter to terminals 2 and 3 to check
the full throttle switch contacts. There should be no
continuity until the switch is almost fully open. At 72° of
open throttle, the switch should close (continuity). If the
contacts do not close, the switch should be replaced.
To check basic setting of fuel injection system
(LH 2.2)
The procedure below should only be carried out when the
engine function has been disturbed, such as for the replacement of the air mass meter or after major engine work has
been completed. Saab does not recommend any specified interval for this check. For the most accurate results, a highquality digital multimeter should be used.
1. Run the engine until it reaches operating temperature.
2. Connect the positive lead of a voltmeter to the black
wire coming from the oxygen sensor. Connect the negative lead to chassis ground.
NOTE
Do not disconnect the wires from the oxygen sensor.
3. With the engine running, check the voltage signal coming from the oxygen sensor. The voltage should be fluctuating around the middle of its operating range.
Oxygen sensor
3
2
1
(lffiijJ
• voltage at idle, engine
fully warmed. . . . . . .. approx. 0.5 volts (fl uctuating)
NOTE
Fig. 35. Ohmmeter shown connected to throttle position sensor.
LH FUEL INJECTION ADJUSTMENTS
If the sensor is not putting out a signal or if the signal is not
fluctuating, make sure the oxygen sensor system is functioning correctly as described earlier under Oxygen Sensor.
Page 173
Fuel Injection
4. If the voltage is too high or too low, turn the engine off
and remove the harness connector from the air mass
meter. Connect a digital ohmmeter across terminals 3
and 6 of the meter and measure the resistance.
Air Mass Meter Base Setting
• resistance measured at meter
terminals 3 and 6
240-27
8. Install a new anti-tamper plug anti-tamper plug from the
side of the air mass meter.
If the correct oxygen sensor reading still cannot be obtained, check the wiring between the air mass meter and the
control unit. Test the oxygen sensor and its circuit. Try substituting a known good air mass meter or oxygen sensor. If no
faults can be found, the LH control unit may be faulty.
380 ohms
To adjust dashpot (LH 2.2)
5. If the resistance reading is incorrect, remove the antitamper plug from the side of the air mass meter. See
Fig. 36. Turn the screw until the correct reading is obtained.
NOTE
The dashpot is mounted to the throttle housing and holds
the throttle valve open for a moment when the throttle is
closed suddenly. This helps reduce the exhaust emission of
unburned fuel. A defective or misadjusted dashpot may be the
cause of a high idle or the cause of an idle that takes a long
time to return to normal when the throttle is released.
If a reading of 380 ohms cannot be obtained, the air mass
meter is faulty and should be replaced.
NOTE
Before making the adjustment below, check that the basic
throttle adjustment is correct.
r
=
1. With the engine at operating temperature, rev the engine up to at least 3000 rpm, then release the throttle
and check that the engine speed returns to normal
within 3 to 6 seconds. If the dashpot fails this test, proceed with dashpot adjustment.
(I /
( ,i
,'.
I
.~
'-..
Fig. 36. Air mass meter anti-tamper plug (arrow).
2. Loosen the dashpot locknut and turn the dashpot so
that its operating rod moves away from the throttle lever. See Fig. 29 above.
3. Rev the engine up to the speed given below and hold
the engine speed steady. Turn the dashpot in until its
rod just touches the throttle lever. See Table n.Tighten
the locknut.
Table n. Dashpot Adjustment Specifications
6. Reconnect the harness connector and start the car.
Recheck the voltage signal at the oxygen sensor as described above. The voltage should now be fluctuating
around the middle of its operating range (approximately 0.5 volts)
7. If the sensor vo~age is incorrect, adjust the screw in the
side of the air mass meter until the oxygen sensor voltage is correct.
Model
Speed at which dashpot rod
touches throttle lever
Non-turbo
2500±100 rpm
Turbo
2600± 100 rpm
4. Recheck dashpot operation. If it still fails the test, replace it.
LH FUEL INJECTION ADJUSTMENTS
Page 174
Exhaust System
252-1
252 Exhaust System
General
252-1
Exhaust System
252-1
To remove and install exhaust system
Exhaust Manifold
252-1
To remove and install exhaust manifold
(normally-aspirated engine)
To remove and install exhaust manifold
"
(turbo engine)
252-4
252-5
252-4
GENERAL
Fig. 1 and Fig. 2 are exploded views of the exhaust systems
used on the cars covered by this manual. Proper exhaust and
emission system functions depend on each component being
free 'from holes, with air-tight seals at all joints. Exhaust systems components are subjected to vibration, extreme temperatures and road hazards. Although the exhaust system is
designed to be maintenance free, regular inspection is warranted due to these harsh operating conditions.
The catalytic converter is similar in appearance to a small
muffler and is mounted to the front pipe. Its chemically-reactive core contains surfaces coated with precious metal catalysts. These catalysts promote chemical reactions in the
exhaust gases to reduce the quantity of harmful pollutants in
the gases. Under normal conditions, the catalytic converter
does not require replacement unless it damaged.
The catalytic converter reduces emissions most efficiently
when the percentage of oxygen in the exhaust system falls
within a narrow range. The oxygen sensor monitors the exhaust gas and provides feedback about combustion efficiency
to the fuel injection control unit. For information on testing and
removing the oxygen sensor, see 240 Fuel Injection. For information on testing other emission control systems, including
the EGR system, see 254 Exhaust Emission Control.
1. Raise the car to a safe level.
WARNING
Never work under a lifted car unless it is solidly supported on
stands designed for the purpose. Do not work on a car that is
supported solely by a jack.
2. Remove the bolts securing the front exhaust pipe to the
exhaust manifold or turbocharger.
3. Loosen all clamps and flange bolts.
4. On turbo models, remove the front pipe-to-transmission bracket.
5. Detach the rubber mountings. Separate and remove
the pipes and mufflers as necessary. Be sure to inspect
the heats shields while the system is removed.
CAUTION
Inspect the heat shields carefully whenever the exhaust system is removed, especially the front heat shields. See Fig. 3.
The front shields protect the ignition switch wiring hamess
from the heat of the hot catalytic converter. If these shields are
deteriorated or damaged, they should be replaced
WARNING
Toxic exhaust gases are colorless and odorless. Do not run
the engine in a non-ventilated area. Repair any structural
damaged to the body that would allow the entrance of exhaust
gases.
EXHAUST SYSTEM
To remove and install exhaust system
New fasteners, rubber hangers and clamps are always recommended. Gaskets should be replaced whenever the
flanged joints are disconnected.
Installation is the reverse of removal. Loosely install and assemble the complete system. Then evenly tighten the clamps
and mounting bolts. Make sure that no part of the exhaust system contacts any part of the body.
Make sure the rear retaining rings are slightly preloaded toward the front of the car. See Fig. 4. Install the clamps 9 rnm
(1/3 in.) from the ends of the pipes. See Fig. 5. When installation is complete, start the engine and check for leaks by briefly
placing a clean rag over the tailpipe and listening for hissing
sounds. If any leaks are present, loosen the system fasteners
and readjust the system. Check the system alignment by driving the car over rough road surfaces to check if the system
contacts the underbody.
EXHAUST SYSTEM
Page 175
252-2
Exhaust System
Upper front
heat shield
Gasket
Lower front
heat shield
Retaining
bracket
B7035-SR8814-900 USA
Fig. 1. Exploded view of exhaust system used on cars with normallyaspirated engines.
EXHAUST SYSTEM
Page 176
Exhaust System
252-3
Middle
extension
pipe
Retaining ring
\
Clam"
Fig. 2.
Rear muffler
87046-SF2793 AA890
Exploded view of exhaust system used on cars with turbocharged engines.
EXHAUST SYSTEM
Page 177
252-4
Exhaust System
NOTE
Anti-seize compound used on threaded fasteners and exhaust pipe joints will make future replacement easier.
~
~
~I'
-t;:2-5
-------li
i
CAUTION
Do not let anti-seize compound or penetrating oil come in contact with the slit portion of the oxygen sensor body. The oxygen sensor will be destroyp.d.
-r
-----1-·t
I
__________ JI
9± 2.5
l
i \
r--.....
~~ '----.:~
87110-S2I1110
o
Fig. 5. Exhaust system clamps should be installed 9 mm (1/3 in.)
from end of pipe.
EXHAUST MANIFOLD
Front heat shield
87116-S2I1123
The exhaust manifold is made of cast iron. Normally-aspirated models use a two-piece manifold assembly. Turbo models use a one-piece manifold. See Fig. 6. Always use a new
manifold gasket when installing the manifold.
CAUTION
Do not let cold water come in contact with a hot exhaust manifold or turbocharger. The manifold could crack as a result.
Rear heat shield (turbo)
87116-S2l1122
Fig. 3. Exhaust system heat shields.
To remove and install exhaust manifold
(normally-aspirated engine)
1. On cars with manual transmission, remove the oil filler
pipe from the side of the transmission. Plug the opening in the transmission.
2. Separate the front exhaust pipe from the manifold.
3. Remove the mounting bolts from the center manifold
and remove it from the cylinder head.
4. Remove the upper-left manifold mounting stud from the
cylinder head by locking two nuts on the stud. Use the
inner nut to thread the stud out.
5. Remove the remaining mounting bolts from the outer
manifold_ Remove the manifold by pivoting the front
end up while lifting it off the studs. See Fig. 7.
Fig. 4. Rear muffler retaining ring shown preloaded for exhaust
system expansion.
Installation is the reverse of removal. Use new mounting
nuts, tightening them evenly to their specified tightening
torque.
Tightening torque
normally-aspirated engine
• exhaust manifold to cylinder head .. 20 Nm (15 ft-Ib)
EXHAUST MANIFOLD
Page 178
Exhaust System
Normally-aspirated engine
l
252-5
To remove and install exhaust manifold (turbo
engine)
1. Remove the battery from the car.
2. Remove the ignition distributor as described in 340 Ignition System.
3. Remove the distributor heat shield from the cylinder
head.
4. Disconnect the turbocharger air intake pipe, air outlet
pipe and oil supply pipe from the turbocharger. Disconnect the turbocharger oil supply pipe from the engine.
87117-$211121
Turbocharged engine
5. On 1988 and later models, drain the cooling system as
described in 261 Radiator and Cooling System. Then
remove the coolant lines from the turbocharger.
6. Remove and label the small pressure hoses from the
APe solenoid on the radiator crossmember.
7. Where applicable, disconnect the EGR pipe from the
exhaust manifold and from the EGR valve.
8. Remove the mounting bolts from the turbo unit bracket
at the transmission.
i
I
I~
-------
87117-$211136
9. On cars with manual transmission, remove the oil filler
tube from the side of the transmission. Plug the opening in the transmission.
Fig. 6. Exhaust manifolds.
10. Disconnect the oil return pipe from the turbocharger.
11. Unbolt the front exhaust pipe from the turbocharger.
12. Remove the exhaust manifold mounting nuts, spacers,
and washers. Slide the manifold with turbocharger off
the studs and out of the car. Separate the turbocharger
from the exhaust manifold, if necessary.
Installation is the reverse of removal. Use new mounting
nuts, tightening them evenly to their speci'fied tightening
torque. Replace the manifold gasket. Replace all turbocharger oil line seals and gaskets. For additional information on the
turbocharger see 291 Turbocharger.
87125-3211167
Tightening torque
turbo engine
• exhaust manifold to cylinder head .. 25 Nm (18 ft-Ib)
Fig. 7. Exhaust manifold being removed,
EXHAUST MANIFOLD
Page 179
Exhaust Emission Control
254-1
254 Exhaust Emission Control
General
254-1
Evaporative Loss
Control Device (ELCD)
254-1
Exhaust Gas Recirculation
System (EGR)
254-3
Electronic EGR System (1990 and later
Californian and SPG models only
To test EGR valve
To test modulating valve and signal
to modulating valve
To test EGR temperature sensor
254-3
254-4
254-4
TABLES
a. ELCD Systems Applications
254-1
254-3
GENERAL
This repair groups covers only the Evaporative Loss Control Device (ELCD) and the Exhaust Gas Recirculation (EGR)
system. For repair and troubleshooting information of other
emissions-related systems, such as the oxygen sensor system, the throttle dashpot, and the Automatic Idle Control (AIC)
system, see 240 Fuel Injection.
For proper exhaust emissions, a number of engine systems
(ignition, fuel injection, and emission controls) must be functioning correctly. Because of the interrelation of these systems, it is difficult to isolate general driveability problems by
examining a single emission control system. For this reason,
engine management and driveability troubleshooting information can found in 200 Engine-General. This information is
organized to help isolate problems and suggest more specific
troubleshooting steps by taking all of the interrelated systems
into consideration.
NOTE
Cars with LH 2.4 and LH 2.4.2 fuel injection systems feature
built-in diagnostic circuitry that detects and stores system
faults in the LH control unit's memory, including emissions-related faults. When a system compensates for values that are
outside the permitted limits, a fault code is generated in the
control unit's memory. It is highly recommended that checking
for any faults codes be the first step in diagnosing an emissions-related fault. See 240 Fuel Injection for instructions on
viewing the fault codes.
EVAPORATIVE LOSS CONTROL DEVICE
(ELCD)
All 900 models use a charcoal-filter canister to absorb vapors from the fuel tank. This system is known as the Evaporative Loss Control Device (ELCD). See Fig. 1. The fuel tank is
vented to the canister and the canister is in turn vented to the
intake manifold via the ELCD valve. When the engine is run
ning, the accumulated vapors in the canister are drawn
through the open ELCD valve and into the engine to be
burned. The charcoal canister is mounted in the driver's side
wheel well, behind the headlight. The ELCD valve is mounted
to the top of the canister. Two types of ELCD systems are
used, depending on the fuel system installed. See Table a.
87918-S2l118
Fig. 1. Evaporative Loss Control Device (ELCD) system. Note how
hoses run through headliner.
Table a. ELCD Systems Applications
Fuel Injection Systems'
ELCD System
LH 2.2
Vacuum operated
LH 2.4, LH 2.4.2
Electronically controlled
'see 240 Fuel Injection for system identification
The ELCD valve controls the amount of fuel vapors drawn
into the engine and therefore can affect the fuel mixture and
exhaust emissions. A fault in the ELCD system can often result in an overly lean or an overly rich mixture, causing driveability problems, especially at idle.
NOTE
On most models, charcoal canister replacement is a maintenance procedure scheduled at a specified mileage interval.
See 1 LUBRICATION AND MAINTENANCE for the recommended service interval.
EVAPORA TlVE LOSS CONTROL DEVICE (ELCD)
Page 180
254-2
Exhaust Emission Control
On models with LH 2.2 fuel injection, a vacuum-operated
diaphragm valve on the canister controls when fuel vapors are
drawn into the engine. See Fig. 2. Vacuum from the intake
manifold opens the valve during cruising.
2
,------------------_._------~
5
--;r:rn(
IL.Jr' ::.
.,. . ,.
3
~rl
J
•
~4
I
•
1-~~~~~~~~~,./B7919-S2l1000 I
1. Fuel tank
2. Activated-charcoal
canister
3. Intake manifold
4. ELCD valve
5 Throttle plate
6. Hose
j
..................
87911-S2l1001
- -
Fig. 2. Schematic view of ELCD system.
To test the vacuum-operated ELCD valve, disconnect the
vacuum hoses from the valve. If necessary, remove the canister from the car. Blow into the lower (larger) hose fitting on the
valve. Air should not pass through the valve. Connect a handheld vacuum pump to the top hose fitting on the valve. With
vacuum applied to the top fitting, air should now pass through
the lower fitting. See Fig. 3. If any faults are fou nd, the valve is
faulty and should be replaced.
On models with LH 2.4 and LH 2.4.2 fuel injection, an electric solenoid valve controls canister purge. The valve is
opened and closed electronically by the LH control unit. With
the engine running, the valve should be audibly buzzing, and
the buzzing noise should vary in intensity depending on engine speed.
The electric ELCD valve can be tested by disconnecting its
harness connector and supplying battery voltage to the valve
terminals. The valve should click open when voltage is supplied. If no faults are found, check for voltage to the valve's
connector with the ignition in the run position. There should be
battery voltage between the gray/white wire and ground. If
voltage is not present, check for faults using the appropriate
wiring diagram shown in 371 Wiring Diagrams, Fuses and
Relays. If voltage is present, check the electrical resistance of
the valve. See Fig. 4. If the resistance is not as specified, the
valve should be replaced.
EVAPORA T7VE LOSS CONTROL DEVICE (ELCD)
1. to Inlet manifold
2. ELCD valve shown open
3. ELCD valve shown closed
4. from Fuel tank
Fig. 3. Vacuum-op8mted ELCD valve and charcoal canister.
ELCD valve
• valve resistance
40 to 60 ohms
40-60 Ohm
87952
Fig. 4. Electric ELCD valve resistance being measured (shown
schematically) .