1973 OPEL MANTA overheating

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.

6D. 421973 OPEL SERVICE MANUAL
EXHAUST SYSTEMS
ALL MODELS
CONTENTS
Subject
DESCRIPTION AND OPERATION: (Not Applicable)
DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS: (Not
Applicable)
MAJOR REPAIR:Page No.
Exhaust System (All Models). . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICA’TIONS:
Torque Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . .
6D-42
6D-42
MAJOR REPAIR
EXHAUST SYSTEM (ALL MODELS)
Removal1. Remove exhaust pipe from exhaust manifold.
2. Loosen front exhaust pipe to mufller clamp and
pull exhaust pipe out of muffler.
3. Remove muffler damper rings.
4. Remove center exhaust pipe clamp. Remove rearmut&r and tail pipe(s) as an assembly. See Figure
6D-1.5. Remove front exhaust pipe clamp, and remove
front muffler and center exhaust pipe as an assembly,then remove center exhaust pipe from front mufler.
The front mufIler and center exhaust pipe are one
piece on production-built cars but are separate itemsfor service, the tail pipe of the Rallye and GT, has
a dual pipe with one resonator.
InstallationCheck rubber damper rings for muffler and tail pipe
hanger and replace as necessary.
1. Coat I.D. of rear muffler inlet neck and O.D. of
center exhaust pipe outlet (rear of pipe) with exhaust
sealer compound (several brands are currently avail-able on the market).2. Insert center exhaust pipe into rear mufIler and
tighten clamp.
3. Coat I.D. of front muffler outlet neck and O.D. of
center exhaust pipe inlet (front of pipe) with exhaust
sealer compound.4. Insert center exhaust pipe into front mufiler and
tighten clamp.
5. Install muffler and tail pipe assembly on rubber
damper rings and tighten hangers. See Figures
6D-1and
6D-2.6. Install front exhaust pipe into muffler. Do not
tighten clamp.
7. Be sure to install gasket between exhaust manifoldand exhaust pipe. Using bolts with washers, attach
the exhaust pipe to the exhaust manifold. Torque to
15 lb.ft.8. Align exhaust system and tighten all clamps.
9. Check alignment of exhaust system; make sure
that the exhaust system components have at least
3/4” clearance from the floor pan to avoid possible
overheating of the floor pan.
SPECIFICATIONS
TORQUE SPECIFICATIONSExhaust Pipe to Exhaust Manifold
- 15 lb.ft.