Page 1
Technical data 022-5
Temperature sensor
°C (°F) (+ 10%)
Resistance at -20 (-4) Ohm 14000
10 = (14) Ohm 9000
0 = (32) Ohm 5800
10 = (50) Ohm 3800
15 = (58) Ohm 3000
20 ~=—«(68) Ohm 2600
t s 25 ~=—«(76) Ohm 2000
rd 30 ~=— (86) Ohm 1700
80 (176) Ohm 320
» @
Auxiliary air valve
Resistance Ohm 40-60
o @
» &
AIC valve
Resistance, LH 2.2 Ohm 20+5
LH 2.4 Ohm 7+5
Saab 900
Page 2
Fuel system, B202 engine
Pressure regulator
Bosch No.
0 260 160 225
227
2o7
214 2.5+0.25'-0.15 bar
215 f2,3-2,.8)"
ela
226
235 3.0 +0 .25'-0.15 bar
256 (2:8-3.3F
258
264 2.8 +0.25/-0.15 bar
265 (2.6-3 1)"
Pressure
Permitted tolerances when the test is
carried oul using workshop equipment,
and taking into account! the temperature,
fuel gradé and tha lolarance and call-
bration of the instrument,
Pressures Turbo Other engines
Syslam pressure (at atmospheric
pressure in ihe intake manifold)
-1 986 bar (psi) 2.5+*0.05 (36) 3.0(43) above pressure
1987- bar (psi) 2.640.058 (41) intake manifold
Residual pressure (engine
switched off) bar (psi) | 2:3 (33) 2.8 (39)
Pressure regulator - checking values
Turbo, up to and including 1986
Turbo, as from 1987
Vacuum
0 Dar
-0.2 bar (-2:9 psi)
-0.4 bar (-5.8 psil
-0.6 bar (-8.6 psi)
Pressure
0 bar
+ 0.2 bar (2.9 psi)
+04 bar (5.8 psi)
+ 0.6 bar (8.6 psi)
B202i, as from 1986
Vacuum
0 bar
-O.2 bar {-2:.9 psi)
-0.4 Dar (-5:.8 psi)
-0.6 bar {-8.6 psi)
System pressure
2.5 bar (36 psi}
2.3 bar (33 psi)
2.1 bar (30 psi)
1.4 bar (28 pst)
System pressure
2.5 Dar (36 psi}
2.7 bar (39 psi)
2.9 bar (42 psi)
3.1 bar (45. psi)
System pressure
3.0 bar (43 psi)
2.8 bar (40 psi)
2.6 bar (37 psi)
2.4 Bar (35 pst)
Vacuum
0 bar
-0.2 bar (-2.9 psi)
-0.4 bar (-5.8 psi)
‘0.6 bar (-8.6 psi)
Pressure
O bar
+0.2 bar (2.9 psi)
+04 bar (5.8 psi
+ 0.6 bar (8.6 psi)
System pressure
2.8 Bar (40 psi)
2.6 bar. (47 pst)
2.4 bar (35 psi)
2.2 bar (32 psi)
System pressure
2.8 bar (40 psi)
5.0 bar (43 psi)
3.2 bar (46 psi)
3.4 bar (49 psi)
Page 3
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Technical description 200-1
Technical description
Cl Fuel injection system
B201injectionengine... _ . 200-2
LH Fuel injection system
B202 injectionengine..._ 200-30
Cl Fuel injection system,
B201 engine
GEHSTaL See ee ee 200- 2
Fueltank andfuelpump ...... 200- 5 rae eanes a
Fuel tank with pressurized , F
ain : (US sl ‘igual | eee ar &earlier (N/AAPC)......... 200-31
Fuel accumulator « Rea 2 io. 4 200- 6 Heavy load (not full 3
Fuel filter 2. RRB ee os. 200- 7 A, BROS Ea rite Z
Fueldistributor .... 2... 200- 7 Tiwbo ABE: Riga essed Spas
Line pressure regulator ...... 200- 9 ae
Warm-upregulator ........ 200-10
Regulation of control Overrev protection - Turbo
pressure J) aoa ae AS 200-11 ONEMNOS eee 200-33
Cold-startvalve .........., 200-11
Thermostatic time switch ..... 200-11
Injectlonvalves=s (244.02 la ae 200-12 LH fuel-injection system i"
Air induction system B202 engine
ge. Re a te Rd 200-13 Genera aha lie ee RS Ce 200-34
Airflowsensor .......... 200-13 Injection system, M84
Rubber ductconnector ...... 200-13 EU onwards... .. 2.2.44, 200-35
Throttlehousing ......... 200-14 Injection system, cars
inlet manifold: sce =. Se eas ee 200-14 with catalytic converter ..... , 200-36
Auxiliaryairvalve ....... 2... 200-14 Principle of operation ...... , 200-37
Oxygen-sensor (Lambda) regulated fuel Components
system Pueitankieet: ie Gh ae 200-39
Oxygen (Lambda) sensor. ..... 200-17 Fuel tank ventilation
Catalyticconverter ........ 200-18 &overfillprotection ........ 200-39
Modulatingvalve ... 2.2... 200-19 Fuel pump, M84 6. 6. we 200-40
Fuel distributor... ......~. 200-20 Fuel pump, cars with
Sarma. ut 2,9 Sek ate. 200-21 catalyticconverter ........ 200-41
Fue| boosting sts oy. doe 200-21 i Alaa te ee jee ee 200-44
Fuel pressureregulator ...... 200-42
injection valves’. on. 3 fei, 200-42
M81 ati :
wise gage a 81-83 200-23 Fuel injection manifold ..... . 200-43
Rdisterthihcions, noe 200-23 Throttle-positionsensor ...... 200-43
Fuelboostingon == Auxiliaryairvalve ......,..~;, 200-43
: AIC Valve aig co eet = 200-44
acceleration: -.. 3 2. 2 en 200-24 Tainparative aan
Fuel booster pressure p ; —
euatch 200-24 (NiGiresiston:: 0 vo. 200-45
RAGS ieee a a ERSSYStQMECU” cick. x nee 200-45
Electrical functions - é
angie: oe 200-25 Air massmeter 2°33 6 oo ee 200-46
Elantridaltunotione Alr:cleaneness isy* ©. 4. ee gs 200-47
engine hot 2.6 a ic eee 200-25
Fuel boosting system, M84 onwards
Starting. SYSIBM): «wv =. ys sates 200-27
Accelerationsystem ......., 200-29
Pilrelayterminals ........ 200-30
Page 4
200-2 Technical description
Fuel system, B201 injection
engine
General
The injection system for the engine is the Bosch
Cl (Continuous Injection) system.
An electric fuel pump delivers fuel at constant
pressure to the fuel distributor. The air flow sen-
sor, which measures the flow of air to the engine,
acts mechanically on the fuel distributor,
thereby ensuring that the correct amount of fuel
is metered to the four injection valves. The fuel is
injected continuously into the inlet manifold im-
mediately upstream of the inlet valves.
injection engine
Fuel filter
Fuel distributor
Air flow sensor
Air cleaner
Rubber duct connector
Warm-up regulator
Throttle housing
NOOR WHE
8 Cold-start valve
9 Thermostatic switch
10 Injection valves
11 Auxiliary air valve
12 Power distribution pane!
13 Thermostatic time switch
Saab 900
Page 5
006 qees
Gs Line pressure
Line pressure - 0.1 bar
Ga injection pressure
C3553 Control pressure
[==5] Retum, no pressure
Fuel injection system (N/A US spec)
1 Fuel tank 6 Warm-up regulator
2 Fuel pump 7 Cold start valve
3 Fuel accumulator 8 Injection valves
4 Fuel filter S Line pressure regulator
5 Fuel distributor
€-00Z voNdiosap jediuyooy
Page 6
006 Gees
GS Line pressure
[233 Line pressure - 0.1 bar
EEE injection pressure
C=] Control pressure
CJ Return. no pressure
=
faVzestel
Fuel injection system (N/A US spec)
1 Fuel tank 6 Warm-up regulator
2 Fuel pump with pressurized receiver 7 Cold start valve
3 Fuel accumulator 8 Injection valves
4 Fuel filter 9 Line pressure regulator
5 Fuel distributor
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Page 7
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Technical description 200-5
Fuel tank and fuel pump
The fuel pump is an electric rotary pump
mounted inside the tank. The pump and motor
are totally enclosed and cannot be dismantled
for repair. The relief valve is fitted to the fuel
pump and is actuated when the pressure is ex-
cessive. A non-return valve in the fuel pump out-
let prevents the line pressure dropping to zero
immediately the pump stops.
Fuel tank with pressurized receiver
(Cars with catalytic converter)
A feed pump and a pressurized receiver were in-
troduced on 1983 models. The function of the
pressurized receiver is to maintain pressure on
the suction side of the fuel pump to prevent
vaporization of the fuel.
This supersedes the earlier design in which the
entire fuel tank was pressurized.
The system consists of a feed pump, a main
pump and a pressurized receiver. The feed pump
delivers the fuel from the tank into the receiver.
When the receiver is full, pressure builds up in it
and the main pump mounted in the receiver is
supplied with fuel under pressure.
$2/1320
1 Pressurized receiver
2 Main pump
3 Return fuel
4 To fuel accumulator
5 Safety valve
6 Feed pump
7 Filter
Saab 906
Page 8
200-6 Technical description
Fuel accumulator
The fuel accumulator is connected to the fuel
line from the fuel pump and is situated under-
neath the floor, in front of the fuel tank.
The fuel accumulator has three functions:
1 The fuel accumulator delays the build-up of
pressure in the fuel system on starting, thus
giving the control plunger in the fuel dis-
tributor time to reach the bottom of its travel
before the injection valves open, and pre-
venting too much fuel from being injected.
2 The accumulator absorbs any pressure fluc-
tuations or surges occurring in the system.
3 After the engine has been switched off, the
pressure in the fuel system drops to about 2
bar (29 psi) and is held at this pressure by
the quantity of fuel contained in the ac-
cumulator. Thus, the fuel system remains Mam Line pressure dA
pressurized while the engine is cooling, pre-
pc
vaporization of the fuel and possible starting
difficulties when the engine is hot.
poy);
| Weg LLL b> rat
Fuel accumulator with fuel pump in operation
pe
|
'
S$ 4470
Fuel accumulator on shut-off of engine
Cn = Shut-off pressure
Saab 900
Page 9
a_i
4 Technical description 200-7
Fuel filter
The fuel filter is fitted in the circuit between the
fuel accumulator and the fuel distributor. The fil-
ter has a paper cartridge anda nylon strainer.
—
Fuel! filter
1 Outlet
ua 2 Nylon strainer
. 3 Paper cartridge
4 Arrow, marking the flow direction
|
Fuel distributor 5 Inlet
ew | The fuel distributor distributes the fuel to the in-
jection valves and consists of a fuel control unit
and four pressure regulating valves {two of which
are shown, one for each cylinder.
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Fue! distributor
Line pressure 1 Control plunger
2 Pressure regulating valve
Line pressure -0.1 bar (1.5 psi) 3 Line pressure regulator
[: eae
G28 injection pressure
arena
Aaa
Control pressure
Return, no pressure
Saab 900
Page 10
200-8 Technical description
The skirt of the control plunger is in continuous
communication with the line pressure which also
acts on the bottom of the pressure regulating
valve. When the control plunger is raised by the
lever from the air flow sensor plate, four meter-
ing slots (one for each cylinder), which feed the
fuel to the top of the pressure regulating valve,
will be opened. The pressure above the spring-
loaded diaphragm acts on the latter, deflecting it
downwards and opening the outlet to the injec-
tion valve. A pressure differential of 0.1 bar
(1.5 psi) is maintained between the line pres-
sure and the pressure above the diaphragm. This
constant pressure differential is required to en-
sure that the injected quantity of fuel always re-
mains proportional to the open area of the met-
ering slots and that this is the same for all four
cylinders.
The fuel distributor also contains a line pressure
regulator, passages for the control pressure,
and fuel inlets and outlets.
Pressure regulating valve, partial load
5 4474
Pressure regulating valve, full load
BR Line pressure
Line pressure -0.1 bar (-1.5 psi)
Injection pressure
(oo: Line pressure
Saab 900