Opel Corsa B 1993–2000 Service and Repair Manual: General information

1.3 and 1.4 litre carburettor models

On all 1.3 litre models a Delco breakerless electronic ignition system is used. The system comprises solely of the HT ignition coil and the distributor, the distributor being driven off the end of the camshaft.

The distributor contains an induction sensor (reluctor) mounted onto its shaft and an ignition module (pick-up) fixed to its body.

The system operates as follows.

When the ignition is switched on but the engine is stationary the transistors in the module prevent current flowing through the ignition system primary (LT) circuit.

As the crankshaft rotates, the induction sensor moves through the magnetic field created by the module. When the teeth are in alignment with the module projections a small AC voltage is created. The module uses this voltage to switch the transistors in the unit and complete the ignition system primary (LT) circuit.

As the teeth move out of alignment with the module projections the AC voltage changes and the transistors are switched again to interrupt the primary (LT) circuit. This causes a high voltage to be induced in the coil secondary (HT) windings which then travels down the HT lead to the distributor and onto the relevant spark plug.

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 distributor incorporates a permanent magnet, a 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 by a 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 has no effect on ignition timing. The only 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. 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 all relevant wiring and connections are in good condition and securely connected, fault diagnosis should be entrusted to a Vauxhall dealer.

2.0 litre models

The Motronic systems. The ignition side is very similar to 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.