Carburettor Models; 16-Valve Models - Opel Kadett Owner's Manual

5C•2 Electronic (breakerless) ignition systems
1.6 litre (16SH engine) models and
1.8 litre (18E engine) models
On these models a Bosch (Hall effect)
ignition system is fitted. The system
comprises of the HT ignition coil, the
distributor and the ignition module.
The Hall effect system
incorporates a permanent
detector/amplifier, and four vanes. When a
vane is masking the detector/amplifier no
voltage is induced in the detector, and under
these conditions the module passes current
through the low tension windings of the coil.
Rotation of the distributor will uncover the
detector and cause it to be influenced by the
magnetic field of the permanent magnet. The
Hall effect induces a small voltage in the
detector plate which is then amplified and
triggers the module to interrupt the low
tension current in the coil.
The ignition module in the Hall effect
system incorporates a circuit which switches
off the low tension circuit if the time between
consecutive signals exceeds 1.5 seconds.
The coil and internal circuits are therefore
protected if the ignition is left switched on
inadvertently.
1.6 litre (16SV engine) models
Pre 1988 models
The MZV system is fitted to the 16SV
engine in 1987 and 1988 model years. It is an
electronic system in which the amount of
ignition advance is controlled
microprocessor which receives information on
engine speed, temperature and load. A
correction can also be applied for small
changes in fuel octane rating by means of the
octane rating coding plug. The initial ignition
timing is still determined by distributor
position. The distributor LT pulse generator is
of the inductive sensor type.
A basic adjustment coding plug is provided
for use when checking the initial ignition
timing. When disconnected, this prevents the
control unit from applying ignition advance.
1989 onwards models
The E1 Plus system (also known as EZ Plus)
is a development of the MZV system.
Externally the components are very similar,
but the distributor LT pulses are now
produced by a Hall Effect sensor instead of
inductively. The microprocessor control unit
incorporates a self-diagnosis facility for fault
detection, but this is only accessible to
Vauxhall dealers or other specialists with
dedicated test equipment. The control unit
also limits engine maximum speed by cutting
off the LT pulses to the coil above 6000 rpm.
1.8 litre (18SE engine) models
The E1 61 system (also known as EZ 61) is
fitted to all 1.8 litre engines from 1987 model
year. Like the MZV and E1 Plus systems it
uses a microprocessor control unit to
calculate dynamic ignition advance. LT
signals are derived from an inductive pulse
sensor mounted on the front face of the
cylinder block and a segmented disc attached
to the crankshaft No 1 counterweight.
The distributor in this system serves only to
distribute HT voltage to the correct cylinders.
The distributor position is not adjustable and
distributor
has no effect on ignition timing. The only
magnet, a
alteration possible to the timing is by means
of the octane rating coding plug.
1.4 and 1.6 litre fuel injection
models
The MULTEC CFi engine management
system is described in Chapter 4B. The
system is regulated by an Electronic Control
Unit (ECU) which is continuously supplied
information from various engine, cooling
system and fuel system sensors. The ECU is
then able to make the necessary adjustments
to the fuel and ignition systems in accordance
with the continuously changing demands of
the engine. The ECU also has a diagnostic
function, which can be used in conjunction
with special Vauxhall test equipment, for fault
diagnosis in the ignition system.
With the exception of basic checks to
ensure that
connections are in good condition and
securely connected, fault diagnosis should be
entrusted to a Vauxhall dealer.
2.0 litre models
The Motronic systems are fully described in
Chapter 4B. The ignition side is very similar to
by a
the E1 61 system described earlier. Again, no
alteration to the timing is possible except via
the octane rating plug.
The Motronic M2.5 system fitted to
16-valve models compensates for small
changes in fuel octane rating automatically as
part of the knock control function. The control
unit contains two ignition timing 'maps', one
for high octane fuel and one for lower octane.
If the engine knocks frequently, the control
unit switches to the low-octane map. A steady
period free of knocking will cause a switch
back to the high-octane map. On the C20XE
engine the maps are for 91 and 95 octane
fuel; on the others they are for 95 and 98
octane. 91 octane fuel must not be used in the
engines which are not programmed for it.
2 Ignition system - testing
Warning: Voltages produced by
an electronic ignition system are
considerably higher than those
produced by conventional ignition
systems. Extreme care must be
taken when working on the system with the
ignition switched on. Persons with
surgically-implanted cardiac pacemaker
devices should keep well clear of the ignition
circuits, components and test equipment
all relevant wiring and
Carburettor models and 1.8 litre
(18E engine) models
Note: Refer to the warning given in Section 1
of Part A of this Chapter before starting work.
Always switch off the ignition before
disconnecting or connecting any component
and when using a multi-meter to check
resistances.
General
1 The components of electronic ignition
systems are normally very reliable; most faults
are far more likely to be due to loose or dirty
connections or to "tracking" of HT voltage
due to dirt, dampness or damaged insulation
than to the failure of any of the system's
components. Always check
thoroughly before condemning an electrical
component and work methodically
eliminate all other possibilities before deciding
that a particular component is faulty.
2 The old practice of checking for a spark by
holding the live end of an HT lead a short
distance away from the engine is not
recommended; not only is there a high risk of
a powerful electric shock, but the HT coil or
amplifier unit will be damaged. Similarly,
never try to "diagnose" misfires by pulling off
one HT lead at a time.
Engine will not start
3 If the engine either will not turn over at all,
or only turns very slowly, check the battery
and starter motor. Connect a voltmeter across
the battery terminals (meter positive probe to
battery positive terminal), disconnect the
ignition coil HT lead from the distributor cap
and earth it, then note the voltage reading
obtained while turning over the engine on the
starter for (no more than) ten seconds. If the
reading obtained is less than approximately
9.5 volts, first check the battery, starter motor
and charging system as described in the
relevant Sections of this Chapter.
4 If the engine turns over at normal speed but
will not start, check the HT circuit by
connecting a timing light (following the
manufacturer's instructions) and turning the
engine over on the starter motor; if the light
flashes, voltage is reaching the spark plugs,
so these should be checked first. If the light
does not flash, check the HT leads
themselves followed by the distributor cap,
carbon brush and rotor arm using the
information given in Chapter 1.
5 If there is a spark, check the fuel system for
faults referring to the relevant part of Chapter
4 for further information.
6 If there is still no spark, check the voltage at
the ignition HT coil "+" terminal; it should be
the same as the battery voltage (ie, at least
11.7 volts). If the voltage at the coil is more
than 1 volt less than that at the battery, check
the feed back through the fusebox and
ignition switch to the battery and its earth until
the fault is found.
7 If the feed to the HT coil is sound, check the
coil's primary and secondary
all wiring
to
winding