Opel 1900 1973 Service Manual page 42

4. Rota&distributor counterclockwise slightly until
contact pbints just start to open. This must be
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 Timing
Contact boint gap (.016" at widest gap) or dwell 50
minus 3 degrees
degrees plus or
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.
6. Tightq clamp bolt securely and recheck timing
mark ahgnment.
7. Reconnect vacuum hoses and adjust engine idle
speed an: mixture.
WIRE INSPECTION
resistance type. These secondary ignition wires
reduce television and radio interference.
done
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
always be
should
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.
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
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
IGNITION
Figure fC-5 Checking Ignition Wire Resistance
bad connection in the starter circuit or a bad
volts).
SYSTEM