Page 201
Indication (nominal value)
Deviation from nominal value. Possible faults and their elimination.
No reading: Open circuit: plug connection of cable 16 from main relay terminal 87
to control unit. Main relay does not energize: check for voltage at terminal 86 of main
relay; if no voltage, check cable connecting terminal 86 of main relay and terminal 15
of ignition coil series resistor. Measure voltage at terminal 87 of main relay: if
voltage “0", check cable connecting main relay terminal 30/51 and battery +. Check
central ground cable.
Voltage below 11 volt: Battery flat, contact resistance in cable 16, 11 or at relay
contacts. (Check cables, exchange main relay.)
As for voltage | but check cable 24.
11...12.5
(11...12.5 V)
9.0...12
(9.0...12V)
No voltage, starter operates: Open circuit from starter terminal 50 to control unit
(check cable 18 to the control unit terminal 18).
No voltage as above, starter does not operate: Ignition/starter switch defective,
open circuit in cable.
Voltage below 9.0 volt: Battery flat, voltage drop in the cable from ignition/starter
switch to terminal 50 of the starter too high (check cable with voltmeter).
When full deflection on the instrument is not obtained, the voltage of the vehicle
battery is too low.
See also test stage “voltage |”.
Resistance “00” (c0Q)
Resistance “0”: Short circuit to ground in cable or at Pressure sensor (pull plug out
of pressure sensor and if test instrument shows ““o9", replace pressure sensor.
If test instrument remains at “0”, the cables 7, 8, 10 or 15 may be short circuited;
replace cable harness.)
Resistance below “co”, but not “0”: Damage to insulation (proceed as described
above).
0.8...1.2 on the Q scale
(approx. 90 Q)
Resistance considerably smaller than nominal value: Damage to insulation (pull
plug out of pressure sensor and if test instrument shows “co”, replace pressure
sensor).
Resistance “0”: Short circuit to ground, short circuit in secondary windings (pull
plug out of pressure sensor and if test instrument shows “oo, replace pressure
sensor).
Resistance considerably larger than nominal value: High contact resistance (test
plugs and cables for corrosion or open circuits).
Resistance “co”: Open circuit. Bridge plug
as shown in illustration. If test instrument
shows “0”, replace pressure sensor. If “coo”
indicated, check cables.
oo
1510 8 7
3...40n the Q scale
(approx. 350 Q)
Jan. 1971
As under “primary”. With resistance “co”, bridge the two inner terminals.
234-14
Page 202
Position of switch B
Operate
To measure
Distributor contact |
Distributor contact II
Rotate distributor by operating starter
for a short time
Functioning of the trigger contacts in
the distributor
Throttle valve switch I, then
Throttle valve switch II
Depress accelerator pedal slowly
Functioning of the temporary enrich-
ment device
Throttle valve switch III
a) Throttle valve in idling position
(closed)
b) Throttle valve slightly open
(approx. 1°)
Functioning of the contacts in the
throttle valve switch
Temperature sensor |
(intake air)
Resistance of the temperature sensor
Temperature sensor II
(cooling liquid)
Resistance of the temperature sensor
Valves
234-15
Adjust instrument again to “co”, if
necessary (switch in position “Valves”).
Pushbuttons:
1 = injector for cyl. 4
2 = injector for cyl. 1*
3 = injector for cyl. 2
4 = injector for cyl. 3
*cyl. 1 is at the rear end of the engine
Resistance of the windings in the
injector with cable
Sept. 1973
Page 203
Indication (nominal value)
Deviation from nominal value. Possible faults and their elimination.
Alternating between “0” and “a”
(0/ co 2)
If the needle of the test instrument does not swing when starting, i.e. remains at
"oo ” or 0", check terminals 12, 21 and 22 at the trigger contact holder.
If the terminals and the cable harness are not defective, replace the trigger con-
tacts.
Instrument needle swings approx.
10 times between “0” and “ oo”.
(Alternately 0/co &)
As the fully depressed accelerator pedal is released, the needle of the instrument
must remain in the “co” position. If 0” is shown then the throttle valve switch is
defective, replace.
a) 0(0Q) a) Resistance “oo”: Throttle valve switch incorrectly adjusted or open circuit in
cable (check adjustment, pull out plug and bridge as shown in illustration).
If still at “co ", replace cable harness, otherwise replace throttle valve switch.
b) co (co Q) b) Resistance “0”: Throttle valve switch incor-
rectly adjusted or short circuit in the cable.
Pull out plug; if the test instrument still in-
dicates “0”, replace the cable harness, other-
wise adjust or replace throttle valve switch. o oO
me: S$ 5352
1. 1.7 and 1.85 | engines
2. 2.01 engine
Tee pes) Nominal value is at 20° C (68° F). At higher temperatures, the resistance is smaller.
(300 2) Reading “oo”: Open circuit (pull out plug and bridge; if instrument shows “0”,
20° C (68° F), replace temperature sensor, otherwise replace cable harness).
strongly affected by temperature:
higher temperatures give lower values
Reading “0”: Short circuit (pull out plug, if reading is the same, cable is defective.
If the test instrument then shows “ co”, replace temperature sensor.)
05... 25
(approx. 2.5 kQ)
20° C (68° F),
strongly affected by temperature:
higher temperatures give lower values
See temperature sensor |.
ae)
(2.4 Q at 20° C = 68° F)
Dec. 1975
Resistance “0”: Short circuit in the cable or in the injector (pull plug out of injector
concerned and if test instrument shows “ ca”, exchange injector; otherwise replace
cable harness).
Resistance “co”: Open circuit in the cable or in the injector windings. Bridge
contacts in injector plug; if test instrument then shows “oo”, cable harness is
defective. If “0”, then injector is defective.
Resistance over “3”: Ground cable from the injectors has a bad connection on the
engine.
“
234-16
Page 204
Position of switch “A”
Switch “B” has no effect
Operate
To measure
Valve check
Press “pump” button
Pressure in fuel line (connect pressure
gauge: disconnect fuel line between
cyl. 1 and pressure regulator and con-
nect pressure gauge in between)
Press “pump” button briefly.
Leaks in the fuel system
(pressure side)
Note: Carry out the following test only
if injectors are thought to be defective.
Injectors are removed.
Pressure build-up:
Press “pump” button.
Press buttons 1, 2, 3 and 4, one after
the other. —~
Visual check of the injector spray.
Collect fuel.
Checking start valve and
temperature switch:
a) Cooling liquid over
0° + 5° C (+32° + 9°F)
b) Cooling liquid below
0° + 5° C (+32° + 9° F)
1. Press “pump” button, operate starter
briefly.
2. Connect temperature switch to
ground.
Press “pump” button and operate star-
ter briefly (temperature switch again
normally connected).
Function of the temperature switch and
start valve.
Switch off ignition and remove pressure gauge.
234-17
Jan. 1971
Page 205
Indication (nominal value) Deviation from nominal.value. Possible faults and their elimination.
No pressure build-up (pump does not start up): Pull out 2-pole plug from pump,
Press “pump” button and measure the voltage with the voltmeter at the plug con-
tacts.
an ; Reading 12 V: Pump defective, exchange.
Conc. the nominal value of the fuel Reading "0": Check by listening whether relay energizes or not.
Pressure see table on page 234—21. | If yes: Break in cable from pump relay terminal 87 to pump plug or from plug to
A deviation of +0.2 bar from the ground.
nominal value can be allowed. Fuse no. 8 in main fuse box blown.
If cables are good, pump relay is defective.
If not: Break in cable from main relay terminal 87 to pump relay terminal 86 or from
pump relay terminal 85 to cable 19 to the control unit. If the cables are in order,
exchange the pump relay.
Pressure above or below nominal value: Pressure regulator incorrectly ad-
justed (readjust); if adjustment is not possible, pressure regulator defect
(replace).
Pressure may drop back to 1.2 bar Pressure drops quickly below 1.2 bar (kp/cm2 17 psi) as soon as the”pump” button is
(kp/cm2, 17 psi); after this, any released: Leak in pressure system (from fuel pump to pressure regulator). Close off
Pressure drop should be very slow. fuel pressure hose coming from the pump just before the pressure pipe. If no
Pressure drop occurs, the leak is at the pump or in the pressure line. If the pressure
continues to drop, the leak should be sought at the connections to the injectors, in
the injectors themsleves or at the pressure regulator. Close off the fuel line with a
clamper before the pressure regulator. If the pressure continues to drop, check
injectors and start valve for leaks (see the following test step). If the pressure
remains constant, the pressure regulator is defective and must be replaced.
Build up the pressure several times during the test as required. Make visual check
to see if leaks occur at hose connections (also pressure gauge connection).
Press “pump” button and check visually for leaks.
The injector orifice may become wet, but not more than two drops should form per
minute on the injector. If no leaks have been determined, exchange the pressure
regulator.
1. Pressure should not drop visibly. 1. Pressure drops steadily as the starter is operated: temperature switch defective,
exchange.
2. Start valve injects, gauge pressure | 2. Pressure does not drop when the starter is operated: check cable 31 from start
drops. valve to starter terminal 50 for breaks. If broken, renew cable harness; otherwise
check start valve.
Winding resistance 4.2 Q at 20° C (68° F).
Pressure must drop slowly. If the pressure does not drop, renew temperature switch or check start valve as
described under 2. above.
Nov. 1972 SAAB 234-18
Page 206
Important! The following points must be observed before starting up the engine:
4. Never let the engine run without the battery connected.
2. Never use a high speed battery charger as a starting aid.
3. When using a high speed charger to charge the battery in the vehicle, the battery
should be disconnected from the rest of the electrical system.
4. Check the polarity of the battery before installing.
Starting the engine:
Cold engine: without depressing the accelerator pedal. \f the engine is warm and
the outdoor temperature is high, a slight depression of the accelerator pedal will
assist starting.
Important!
Please observe the test procedure exactly.
Connect the control unit only after the ignition has been switched off.
Before starting the engine, do not fail to turn switch “A” to the end position “Distri-
butor contact 1”.
In position “Valve check” all injectors are open. The engine does not start.
Test with control unit connected:
Connect the control unit to the multiple plug
of the test instrument.
The position of the switch “B” has no in-
fluence on the test procedure.
Position of switch “A” Operate To measure
Distributor contact |, then Let engine run at about 2000 rev/min Displacement of the trigger contacts in
Distributor contact I! Switch over test instrument from the ignition distributor.
distributor contact | to
distributor contact II
234-19 SAAB
Nov. 1972
Page 207
Indication
Deviation from nominal value. Possible faults and their elimination.
Needle moves toward full deflection
and then oscillates about an average
value. When switching over from distri-
butor contact | to II, max. deviation
may be 2 graduations from the average
value on the voltage scale.
If deviation is greater, the trigger contact holder in the ignition distributor should
be renewed.
Jan. 1971
234-20
Page 208
Fuel pressure
CAUTION
The various components of the injection system are
carefully matched to each other and must only be
assembled in the combinations shown in the table
below.
Electronic Pressure Injection Fuel
Engine | control unit sensor valve pressure Remarks
Part number Part number Part number bar (kp/cm2)
Saab No. Saab No. Saab No.
1.71 837601 837602 837605 2.0
Bosch No. Bosch No. Bosch No.
0 280 000 010 0 280 100 009 0 280 150 001 )
0 280 150 013%)
Y
Saab No. Saab No. Saab No.
1.851 | 838069 838070 838071 2.0 Up to and incl. ch.No.
8 ts 99.074.342 and all 5
Bosch No. Bosch No. Bosch No. cars with 1.85 | en-
0 280 000 018 0 280 100 018 0 280 150 004 gines destined for USA
\ 0.280 150 014%)
Saab No. Saab No. ‘SRatNe-
1.85 | 837601 837602 837605 2.3 As from ch.No.
Bosch No. Bosch No. Bosch No. 99.074.343
0 280 000 010 0 280 100 009 0 280 150 001
0 280 150 013%)
Saab No. Saab No. Saab No.
2.01 835070 835071 835071 2.2 Up to and incl. ch.No.
835466*) 99732000357
Bosch No. Bosch No. Bosch No.
0 280 000 039 0 280 100 115 0 280 150 004
0 280 150 014%)
Saab No. Saab No. Saab No. )
2.01 835070 835071 838071 2.0 As from ch.No. ;
835466*) 99732000358
Bosch No. Bosch No. Bosch No. ~
0 280 000 039 0 280 100 115 0 280 150 004
0 280 150 014%) )
Saab No. Saab No. Saab No.
2.01 835070 835493 838071 1.9 Cars with automatic
835466%) transmission destined
Bosch No. Bosch No. Bosch No. for USA, as from
0 280 000 039 0 280 100 118 0 280 150 004 ch.No. 99742000001
Colour-coded 0 280 150 014%)
with green
x) Alternative to earlier design.
Dec. 1975°
Page 209
4. Trouble-shooting chart for defects in fuel injection system
Trouble
Cause
only. Prerequisite is that the ignition system and the engine be in
satisfactory condition.
Remedy
Engine will not start.
Fuel pump not running.
a
1, Fuse to pump relay terminal 30/51 blown.
Cables to pump or pump relay or cables
on fuel pump relay defective.
2. Check plug on fuel pump for good con-
nection.
Renew 8 amp fuse. Check whether pump
relay energizes (switch ignition on and off
and listen for audible action of relay), if
necessary test with voltmeter.
No voltage at terminal 86 of pump relay
(12 V), because main relay not operating or
cable defective.
Eliminate any existing open circuit.
Voltage present at terminal 86 of pump relay
but no ground connection at terminal 85.
Fuel pump operates for approx. 1—2 sec.
after switching on ignition. Check with volt-
meter; ground for terminal 85 is made by
control unit. Replace control unit.
Open circuit in cable from pump relay to
pump plug.
Eliminate open circuit.
(Check plug connection.)
Engine will not start.
Fuel pump runs.
Connection from cable harness (cable 18) to
starter terminal 50 defective.
Check with EFAW 228 S 10.
Pressure sensor cable not connected or open
circuit.
Push on pressure sensor cable or repair.
Open circuit in cable connection at temper-
ature sensor II (cooling liquid).
Check cables, if necessary exchange temper-
ature sensor.
No pressure building up in fuel ring main
(pipe compressed or pressure regulator de-
fective).
Check pressure with gauge; if necessary ex-
change pressure regulator.
Engine will start cold,
but stalls.
YU
Cable connector for triggering contacts not
pushed on at ignition distributor or open
circuit in cable.
If necessary, connect test instrument
EFAW 228 S 10 and localize the fault; ex-
change trigger contacts or cable harness.
Trigger contacts defective. Replace.
See also “Engine will not start”.
Pressure sensor defective. Replace.
Engine cuts out when
driving (usually preceded
by misfiring)
1. Trigger contacts have excessive contact
resistance or are dirty.
2. Plug loose.
3. No fuel pressure.
1. Replace trigger contacts.
2. Check.
3. Measure pressure. Determine cause.
Jan. 1971
234-22
Page 210
Trouble
Cause
Remedy
Engine runs irregularly,
one cylinder not firing,
exhaust white.
One injector sticking.
Exchange.
Connection to injector or injector coil not in
order.
Check connections, exchange injector. Test
with instrument EFAW 228 S 10.
Engine misfiring but not
caused by ignition
system.
Loose connections, main ground cable has
poor connection to car body.
Check connections, tighten up ground con-
nection.
Engine not reaching full
power.
Fuel pressure too low.
Check pressure regulator.
Pressure sensor defective.
Exchange.
Throttle valve does not open sufficiently.
Check throttle valve.
Fuel consumption too
high.
“Information” sensors or the control unit not
functioning correctly or the electrical con-
nections have too high contact resistances.
Test the system according to section 3.
Throttle valve switch incorrectly adjusted.
Adjust with test instrument EFAW 228 S$ 10.
Fuel pressure incorrect.
Check pressure regulator, if necessary ex-
change.
Engine hunts excessively
at idle (between 1,000
and 1800 rev/min)
Hose between auxiliary air regulator and in-
duction manifold detached or defective.
Push hose into position or replace.
Throttle valve stop incorrectly adjusted (too
wide open).
Readjust throttle valve stop.
Idling speed set too high.
Adjust idling speed.
Engine misfires when
accelerating.
Temporary enrichment device in throttle valve
switch not functioning or plug incorrectly
connected.
Check throttle valve switch (test instrument
EFAW 228 S 10).
Too high idling speed.
Idling speed cannot be
adjusted.
234-23
1. Idling air system leaks.
1, Check idling air system.
2. Small rubber sealing ring (spare part No.
837614) under the injector leaks.
2. Replace rubber sealing ring.
3. Throttle valve adjustment incorrect.
3. Readjust throttle valve.
Sept. 1973