The ignition system - the spark in your vehicle

The ignition, i.e. the ignition of the fuel takes place with the ignition system of the car. Fire residues and mechanical wear are unavoidable in this system. Therefore it is worthwhile to check and maintain the ignition system regularly. In our shop you will find high-quality spare parts for both petrol and diesel engines. Additionally we explain all components and the functions of the individual parts in the lower part of the page!

Differences between an annealing and an ignition system
Fully electronic ignition system
The components of the ignition system / glow system briefly explained
Detect defects in the ignition system and glow system

Glow plugs

Ignition sets

Ignition cables

Spark plugs

Ignition locks

Ignition coils

Distributor

The differences between a glow and an ignition system briefly explained

With a petrol engine, a fuel-air mixture is sucked in. This is then compressed and the spark plug ensures ignition. The hot gas sets the piston in motion towards the crankshaft. Via the connecting rod, this movement is converted into the rotary movement of the crankshaft. The diesel engine, on the other hand, only sucks air into the cylinder. This is mixed with the fuel only in the combustion chamber. The very high pressure in the combustion chamber causes the mixture to ignite. Thus the piston is pressed down here as well. Because of the different working methods, the diesel engine is also referred to as the annealing system.

The differences between the two motor drives once again briefly compared:

The stationary ignition (fully electronic ignition system)

Modern gasoline engines today are equipped with fully electronic ignition systems. This means that each cylinder has its own ignition coil. This is connected to the ignition distributor, which in turn distributes the voltage to the individual spark plugs. The fully electronic ignition system has no more mechanical parts and is therefore less susceptible to wear.

The following components belong to an ignition system in a petrol engine:

• Spark plugs
• ignition coil / ignition modules
• Ignition distributor
• Ignition switch
• Ignition leads / ignition cables

An annealing system for diesel engines includes the following components:

• Glow plugs
• Control unit / preheater relay

The components of the ignition system / glow system briefly described

1. Ignition coil / ignition modules:

• The technical structure is similar to a transformer
• Its task is to convert a low voltage (on-board voltage) into a high voltage
• It contains an iron core and two windings of copper wire (primary and secondary winding)
• Each cylinder has its own ignition coil with spark plug
• Current flows through the primary winding and thus a magnetic field is created around the iron core
• The secondary winding has many more turns, so a high voltage is generated
• The current is switched off, thereby the magnetic field collapses and the ignition spark occurs
• Ignition coils bring the on-board voltage from 12V to 15.000 to 30.000 Volt

2. Ignition distributor:

• In modern, fully electronic ignition systems the ignition distributor is no longer installed
• It transmits the current of the ignition coil always alternately to the individual spark plugs
• Rotating distributor rotor transmits current to the respective distributor caps
• Thus the sparks are forwarded to the spark plugs
• One rotation of the ignition distributor corresponds to the rotation of the camshaft

3. Ignition cables/ignition leads:

• They transmit the voltage generated by the ignition coil to the spark plug
• They must withstand very high temperatures and vibrations
• Even small defects can cause the engine to run unevenly
• In modern vehicles, single spark ignition coils are often installed, these are located directly on the spark plug

4. Spark plugs:

• In the ignition system they emit the spark from the energy generated in the ignition coil
• The ignition spark jumps over between the middle and ground electrode
• Thread length, heat value and electrode distance must comply with manufacturer's specifications
• They must be inserted correctly when replaced with a torque wrench

5. Glow plugs:

• They are installed exclusively in the annealing system of diesel engines and heat up the combustion chamber when the engine is started (so-called preheating)
• It reaches a temperature of over 1000 °C in a very short time and thus helps to heat the air
• It is particularly helpful for rapid self-ignition during cold starts at low temperatures
• Modern diesel engines with direct injection achieve a very fast preheating time
• The afterglow time for modern glow plugs takes up to 3 minutes until the cooling water temperature has reached approx. 70 °C. Emissions are thus reduced

6. Ignition switch

• The ignition starter switch is the contact part at the ignition lock, which switches the current
• It activates the starter and the ignition coil of the petrol engine
• With diesel, the ignition switch activates the magnetic valve, which in turn opens the fuel supply
• The ignition lock also protects against theft
• The ignition starter switch usually has four possible settings (the display varies from car to car):
• "0" or "Lock": Switched-off power supply
• "R" or "ACC": Consumers with low power consumption are released, e.g. radio
• "1" or "On": All other consumers are released
• "2" or "Start": This is used to start the engine

Detecting defects in the ignition system and in the glow system

As mentioned above, the components wear out over time. The following symptoms indicate a defect:

• The motor does not start or only starts with difficulty
• Increased fuel consumption
• The car has misfires in the ignition
• Poor acceleration and power loss
• Engine indicator lamp / indicator lamp for glow system starts up
• With diesel engines: the "nailing" sounds even when the engine is warm and smoke develops

Properly functioning ignition coils prevent fuel from running into the catalytic converter and thus protect the vehicle from consequential damage. A defective spark plug can be recognized by its appearance, for example. If it is sooty, oily, white or broken, a specialist should take a look at it. In this way, other damage can also be detected and repaired at an early stage. Other components such as the ignition cables can also wear out due to aging and the enormous heat. If the engine runs unevenly, you should not continue to drive under any circumstances. For this reason, the individual parts of the ignition system should be inspected regularly during maintenance.

For all components of the ignition system the replacement intervals of the vehicle manufacturer should be observed. The higher the quality of the parts, the more reliably they will last until the next replacement interval. With glow plugs, the better the quality, the longer the service life. Therefore you will find only high-quality branded goods in OEM quality at a reasonable price. For many petrol engines we have also put together suitable ignition system sets where you can save money directly. When you select your vehicle, you will be shown suitable offers, which then only need to be checked against the vehicle-specific requirements. If you are not sure which parts are suitable for your ignition system or for your glow system, you are welcome to contact our customer service.