1973 OPEL 1900 rod

I
STARTING SYSTEMlB- 11
but also in the condition of related units, such as battery, switches, electrical
wiring and wiring connections.
ConditionPossible Cause
Correction
When ignition switch is1. Battery discharged.1. Charge battery.
on, cranking motor locks
up or
dra’gs.2. Battery defective.1. Test and replace as required.
Battery terminals loose,Retighten terminals, clean battery
corroded or improperlyposts and terminals and coat them
grounded.with acid-proof grease.
3. Cranking motor or brush1. Eliminate grounds.
terminals grounded.
I
4. Cranking motor brushes do
,
1. Check brushes
- clean or replace
not rest on commutator, or
arcas required. Clean guides on brush-
jammed in their guides, wornholders.
out, oily or clogged.
5. Ignition switch damaged1. Replace ignition switch.
(loose parts preventing switch
I
from closing or burnt parts).
6. Solenoid switch damaged.
1. Repair or replace as required.
7. Excessive voltage drop in1. Check wiring and connections.
wiring switches damaged,Repair or replace switches.
connections loose.
The armature revolves but
1. Drive pinion clogged.1. Clean drive pinion.
the drive binion does not
come into; mesh.
2. Drive pinion or ring gear1. Replace ring gear and
,
teeth flattened or burred.overrunning clutch.
I
3. Poor condition of shaft1. Replace armature and overrunningsplines.clutch.
4. Voltage drop.1. Replace shift lever.
When ignjtion switch is
1. Battery discharged.1. Charge battery.
on, armature revolves
until drive pinion engages
and then
Btops.2. Brush spring tension too1. Check brushes - clean or replace
weak.as required.
3. Cranking motor solenoid or
1. Replace or repair solenoid or
switch defective.
switch.

IIIGNITION SYSTEMlC- 19
11. (Startx position.) The ignition key must be
released as soon as engine starts. The switch then
returns aujomatically to the on position.
IGNITION
GOILThe ignition coil consists of a laminated non- mag-
netic iron
(core enclosed by two coils; the primary
winding and the secondary winding.
The prim+y circuit consists of the power source
(battery), the ignition switch, the ignition coil pri-
mary winding, the distributor breaker points with
ignition condenser connected in parallel, and all con-
necting
lo& tension wiring.
The secondary circuit consists of the ignition coil
secondary ‘winding, the spark plugs, all connecting
high tens@ wiring, the distributor cap and the
ro-tor.
When the’ ignition switch is turned on and the
breaker pdints are closed, current flows through the
ignition
c&l primary winding and produces a mag-
netic field wound the coil windings.
When the breaker points are separated by the revolv-
ing distributor cam, the magnetic field collapses and
induces a high voltage surge in the secondary wind-
ing,
produ;cing a spark between the spark plug elec-
trodes. ,
The ignitidn condenser which is connected in paral-
lel with the breaker points, prevents arcing between
the
separa’ted breaker contacts, and current flow
after~ the breaker points have been separated, thus
causing a kery rapid collapse of the magnetic field
around th$ Ignition coil.
/
IGNITION ‘DISTRIBUTORThe ignitidn distributor breaks the primary current,distributeslthe high voltage surges induced in the coil
secondary winding to the spark plugs according to
the engin< tiring order and sets ignition timing in
relation to. engine RPM and load.
The housi+g of the distributor contains the centrifu-
gal advance mechanism and the movable breaker
plate with’s breaker lever and contact support. The
vacuum advance mechanism is attached to the
breaker plate and mounted on the outside of the
distributor, housing. See Figure lC-1.
The distributor shaft is driven by a helical gear on the
camshaft and in turn drives the engine oil pump. The
ignition condenser is mounted on the outside of the
housing. The engine output is to a large extent in-
fluenced b) the ignition timing. Maximum engine
performance is obtained when the combustion proc-
ess is well underway as the piston starts down on thepower stroke. The air-fuel charges are, however, not
burned instantly, so it is necessary to advance the
spark in relation to the piston top dead center as
engine speed increases or as engine load decreases.
If the spark is too far advanced, the engine knocks,
causing a drop in engine power output and overheat-
ing. If the spark is retarded, part of the energy deve-
loped during combustion is wasted which will result
in reduced engine power output, excessive fuel con-
sumption and overheating.
The ignition distributor has a double acting double
diaphragm vacuum unit. See Figure lC-1. The ad-
vance unit is supplied with “ported” vacuum. That
is, vacuum is supplied from a port in the primary
barrel of the carburetor located just above the closed
throttle valve. This port supplies no vacuum during
idling nor during closed throttle deceleration, but
supplies full intake manifold vacuum at all speeds
where the throttle valve is opened enough to uncover
the port.
Figure lC-1 Ignition Distributor
The retard unit is supplied with intake manifold
vacuum at all times by means of a line connected
directly to the intake manifold. During idling and
deceleration, when there is no vacuum to the ad-
vance unit, the retard unit will cause the timing to be
retarded 5 degrees. However, during part throttle
operation when there is vacuum to the advance unit,
the advance unit will overpower the retard unit so
that the retard unit has no effect on timing.
The purpose of the retard unit is to reduce hydrocar-
bon and carbon monoxide emissions during idling
and deceleration, where they are especially bad.
In order to avoid voltage losses for easier starting, a
plastic cover has been inserted in the distributor be-
low the rotor as a seperator to keep the inside of the
distributor cup free from condensation.

IGNITION SYSTEMlC-214. Rota&distributor counterclockwise slightly until
contact pbints just start to open. This must be done
very carefully or engine will not start.
5. Install distributor cap. Make sure spark plug wires
are correctly installed in distributor cap, through clip
and on spark plugs.
Finish TimingIContact boint gap
(.016” at widest gap) or dwell 50
degrees plus or minus 3 degrees should always be
checked before adjusting ignition timing.
1. Connekt timing light to No. 1 spark plug.
2. Disconnect and plug vacuum advance unit and
retard u$it hoses.
3. Connect a tachometer from distributor side of coil
to
groun$l.4. Start dngine. Set idle speed to 900 RPM.
5. Rotate distributor as necessary to align timing
marks. T;ming mark is a steel ball embedded in the
flywheel and a pointer in a window in the right fly-
wheel housing. See Figure lC-4.:Figure lC-4 Ignition Timing Marks
6.
Tightq clamp bolt securely and recheck timing
mark ahgnment.
7. Reconnect vacuum hoses and adjust engine idle
speed
an: mixture.
IGNlTlOFj WIRE INSPECTION
1. The c$il and spark plug wires are of a specialresistance type. These secondary ignition wires
reduce television and radio interference.
2. Wipe ignition wires with a cloth moistened with
solvent and wipe dry. Bend wires to check for brittle,
cracked or swollen insulation. Defective insulation
will permit missing or cross-firing of spark plugs,
therefore any defective wires must be replaced.
3. If wire insulation is in good condition, clean any
terminals that are corroded and replace any termi-
nals that are broken or damaged. Terminals must tit
tight on spark plugs and in distributor cap.
4. Replace any hardened, cracked or loose cap nip-
ples or spark plug boots.
5. Check resistance of each wire from contact inside
distributor cap to spark plug or coil terminal. Re-
place any wire having over 10,000 ohms resistance
reading. See Figure lC-5.
Figure fC-5 Checking Ignition Wire Resistance
CHECK IGNITION OUTPUT
1. Disconnect secondary coil ivire so that engine will
not start. Connect a voltmeter from the battery side
of the coil primary to ground and check voltage
while engine is cranking. Reading should be 10 volts
or more. Low reading could be caused by a defective
battery, a discharged battery, high starter current
draw, a bad connection in the starter circuit or a bad
connection in the primary ignition circuit.
2. Connect an oscilloscope according to manufac-
turer’s instructions. Disconnect coil wire. Crank en-
gine and read coil output voltage. Reading should
exceed 20 KV (20,000 volts).

lC- 22 1973 OPEL SERVICE MANUAL j
3. Start engine and disconnect a wire from a spark
plug. Read output voltage of disconnected spark
plug circuit. Reading should exceed 20 KV
(20,poO
volts).I
CHECK DISTRIBUTOR
!1. Clean distributor cap and inspect it for cracks or
tracking. Inspect inner segments for erosion and
outer sockets for corrosion.
2. Clean and inspect ignition wires. Make sure resist-
ance of each wire is less than 10,000 ohms. Replace
any defective spark plug boots or distributor
capnipples. See paragraph lC-12.
3. Inspect breaker points and replace if necessary.
Adjust breaker point gap to
,016 inch with rubbing
block on peak of cam lobe or check dwell and adjust
if not 50 degrees plus or minus 3 degrees. 4. Check
dwell variation by reading dwell at idle and at 3000
RPM. Dwell must not vary more than 3 degrees.
Excessive variation means distributor shaft, cam or
breaker plate are worn or damaged--overhaul dis-
tributor and replace defective parts.
5. Check distributor condenser for a minimum series
resistance and insulation leakage. Check for a
capacity between
.15 and .20 microfarads.
6. Check total advance (centrifugal and vacuum) at
2500 engine RPM using a timing light having a dial
for reading advance.
(a) The timing marks are aligned with both the
vacuum advance and the vacuum retard hoses dis-
connected and plugged.
Engine idle should be 900 RPM.
(b) Reconnect vacuum hoses. Run engine at
3600RPM and adjust knob until timing marks are
aligned. Read advance on dial. Maximum centrifugal
advance should be between 28-32 degrees.
7. If total advance is out of specifications, check
centrifugal advance only, at
2500 RPM. Discon+ectand plug all vacuum hoses. Maximum vacuum ad-
vance should be l-5 degrees at 4.5-5.0 in. hg.
8. Replace centrifugal or vacuum advance parts as
required to bring distributor total advance within
specifications.
9. Check operation of vacuum retard unit (rear unit)
by first making sure timing marks are aligned with
vacuum hoses disconnected and at slow idle (700
RPM). Then connect vacuum hose to vacuum retard
unit (rear unit). Timing ball should move in a retard
direction (upward).
CHEICK SPARK PLUGS1. Remove spark plugs. If electrodes are badly worn,
discard plugs. If inner or outer porcelain is cracked
or broken, discard plugs.
2. Note color and general appearance of inner end of
spark plug. Brown to grayish
- tan deposits and slight
electrode wear indicate correct spark plug heat
range. Plugs having this appearance may be cleaned,
regapped, tested and reinstalled.
3. Clean spark plugs in a sand blast type cleaner.
Clean only enough to remove deposits, not enough to
wear away porcelain. If deposits are too hard to
remove or if porcelain is glazed, discard plugs.
4. After cleaning spark plugs, clean tiring surfaces of
electrodes with a line file.
5. Test cleaned spark plugs on a pressure tester by
comparing spark of the used plugs with that of a new
plug. Install tested plugs, using new gaskets.
6. If removed spark plugs have excessive carbon foul-
ing and if the car will be driven mostly at low speeds
in city driving, it is advisable to replace plugs with
a hotter plug, AC43FS.
7. If removed plugs show rapid electrode wear or
inner porcelain breakage at low mileage. Check for
a vacuum leak such as a poor manifold to head fit.
8.
Clap spark plugs carefully (new or cleaned) using
a
,030 round wire feeler gage.IC6
Figure lC-6 Distributor Installation

IGNITION SYSTEM1C. 25
4. Oil sliding parts of breaker plate at “B”. Oil felt
in cam at
“c”. Apply a thin layer of high melting
point grease to the cam, using a finger at “A”. See
Figure K-14.
/
5. Adjust breaker point gap to
,016 inches.
6. Grease control rod eye at “A”. See Figure lC-15.
Figure lC-15 Lubricating Control Rod Eye
7. Rein&all distributor cap nipples and spark plug
boots. If hardened or cracked, use new parts. See
Figure
l!C- 16.
/ Figure lC-16 Reinstalling Nipples
Distribu distributor shaft tang. See Figure lC-17.Figure lC-17 Oil Pump Slot
2. Inspect paper gasket on distributor housing and
replace if necessary.
3. Install distributor with vacuum units in original
position and with shaft cutout (rotor tip) in position
shown in Figure lC-18. Distributor shaft will turn as
distributor is installed, causing the rotor tip notch to
align with the housing notch when distributor is
seated.Figure
1C-18 Shaft Position for Starting Installation
4. Install distributor clamp, bolt and lockwasher tin-
ger tight. Align marks on rotor tip and housing.
5. Install fuel pump.
6. Adjust ignition timing.

lC- 261973 OPEL SERVICE MANUAL /
SPECIFICATIONSIGNITION COIL
Ignition Coil Number
.,.:.................................................................................................K12 V
Ignition Coil Current Draw, Amperes at 12.5 Volts
EngineStopped
...........:.........................._............................................................................3.8Engine Idling
....................................................................................................................2.3
DISTRIBUTORDistributor TypeNumber:
..................................................................................................JFU4
Total Advance (Centrifugal and Vacuum), Engine Degrees at 3600 R.P.M.
EngineRPM
..................................................................................................................29-37Centrifugal Advance, Engine Degrees and RPM
StartAdvance,atRPM
........................................................................................lOOO-1200MediumAdvance,DegreesatRPM
..............................................................7.5-15at1400Maximum Advance, Dkgrees at RPM
..........................................................28-32 at 3600
Vacuum Advance, Engine Degrees and
In. of Vacuum
Start Advance, at In. of Vacuum
................................................................-5 at 2.9-4.1 In.
Maximum Advance, Degrees at In. of Vacuum
........................................l-5 at 4.5-5.0 In.
VacuumRetard,EngineDegreesatClosedThrottle
............................................................-5CondenserCapacityinMicroFarads
...............................................................................15-.20Breaker Spring Tension in Ounces
..............................................................................14 to 19
Breaker Point Gap in Inches
..............................................................................................,016Dwell angle in Engine Degrees
....................................................................................50 + 3
Firing Order
....................................................................................................................l-32-2
SparkPlug or CoilCable,Max.Resistancti in Ohms
..................................................10,ooO
SPARK PLUGSMake and Model
-Production................I....................................................................AC42FS
Make and Model
- Replacement...................................................................................AC42FS
Ifcarbonfouling
occurs,use.....................................................................................AC43FS
SparkPlugTorqueinLb:Ft.
............................................................................................22-29Spark Plug Gap in Inches
...........................................................................................028-.03 1

CHARGING SYSTEMlD- 33
Figure lD-17 Checking Rotor for Ground
Eigure lD-18 Checking Rotor for ShortFibwe 1 D-l 9 Checking Stator for Ground16. Check stator windings for a short, using a low
reading ohmmeter. Check two phases at a time by
holding ohmmeter prods alternately on winding
ends. Ohmmeter should read between
.26 and .29ohms. See Figure lD-20.
301 D20Figure 1 D-20 Checking Stator for Short
17. Clean slip rings with fine emery cloth and polish
them. To avoid generating flat surfaces on slip rings,
spin rotor on a lathe when cleaning and polishing.
Slip rings that are not concentric can be turned down
to a diameter of
l-1/4 inches. When doing this,
remove only enough material to just clean up the
worn surface, then polish slip rings and blow clean
with compressed air.
18. If alternator current output is low one or more
of the nine diodes may be defective. See Figure lD-3.
19. If a defective diode is suspected, test diodes.
Before testing diodes, disconnect them, otherwise it
is not possible to determine which diode is defective.
Use a test light supplied with a DC voltage of not
more than 24 volts.
20. To test a diode, place one test light prod on diode
connection and other on diode housing, then reverse
test light prods. Test light should light brightly in
,
CONNECTIONCONNECTION
I(ANODE)
(CATHODE)
IURRENTCURRENT ,I
CURREN’
FLOW+
+ HOUSING(CATHODE)HOUSING
(AN&E) 3lMD2Figure 1 D-2 1 Positive and Negative Diodes

1 E- 381973 OPEL SERVICE MANUAL
4. Turn switch on to see if wiper niotor will function
with wiper linkage’detached. If wiper motor will ndt
run, disconnect connector at wiper motor and co?-
nect hot lead from battery to terminal No. 53 onwiper motor. If wiper motor runs, the wiper switch
is faulty or there is an break in the lead wire. If wiper
motor still will not run, remove and bench test.
MAJOR REPAIRWIPER TRANSMISSIONS
Removal (1900 and Manta)1. Remove wiper blade (2).
2. Remove the wiper transmission retaining nut,
washer, and rubber seal ring. See .Figure lE-1.
Figure lE-1 Crank Arm Retaining Nut3. Remove instrument cluster housing.
If only left wiper transmission is to be serviced, it can
be done without removing any ‘other instrument
panel components. If the right side, or both, trans-
missions are to be serviced, then
it will be necessary
for complete instrument panel removal. On the Ral-
lye models, the gauge carrier must also be remove&Qn all
1900 and Manta Models the defroster ducts
are secured to the instrument panel cover, by two (‘2)
spring clips, and should not be removed from
dayhcover. Remove cover and duct as, a unit.
4. Remove retaining clips from transmission co;-netting rod pins. Pull connecting rods off pins. See
Item “A”, Figure lE-2.
5. Remove the screws securing the wiper transmis-
sion to the inner side of the cowl (Items “B”, Figuie
13), and remove the transmission assemblies.I
Figure lE-2 Connecting Rod Retaining Clips
Installation1. Place wiper transmissions into position at cowl
and install holding screws.
2. Push connecting rods onto transmission cranking
arm pins and install retaining clips. See Figure lE-2,
Item “A”.
3. Reinstall dash and instrument cluster parts.
4.
1nst:all the rubber seal ring, washer, and transmis-
sion retaining nut. See Figure IE-1.
5. Install wiper blades and check the position of the
blades in the park position. See Figure lE-3.
Figure lE-3 Wiper Blades in Park Position
Removal and Installation of GT W/per Transmission1. Remove nuts and remove both wiper
arms. See
Figure lE-4.
2. Remove three (3) bolts from each windshield