Ignition Systems Ignition Systems

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Distributorless Ignition Distributorless Ignition

Distributorless ignition is used Distributorless ignition is used extensively today by many extensively today by many

manufacturersmanufacturers

Instead of using a Instead of using a ……………………, a special coil ……………………, a special coil

is utilized.is utilized.

Distributor

The basic principle is that of the The basic principle is that of the ‘lost spark’. ‘lost spark’.

The distribution of the spark is The distribution of the spark is achieved by two double ended achieved by two double ended

coils which are fired coils which are fired …………………… by an ECU. …………………… by an ECU. Alternately

When one of the coils is fired, a When one of the coils is fired, a spark is delivered to two spark is delivered to two

cylinders, either 1 and 4, or 2 cylinders, either 1 and 4, or 2 and 3. The spark delivered to and 3. The spark delivered to

the cylinder on compression will the cylinder on compression will ignite as normal.ignite as normal.

The cylinder on the exhaust The cylinder on the exhaust stroke will also have a spark stroke will also have a spark

delivered to the spark plug, but delivered to the spark plug, but this will have ………………… to this will have ………………… to the running of the engine, the the running of the engine, the

spark is ……………… spark is ………………

No effect

Wasted

Label the following components Label the following components

DIS Coil

Crank speed and position sensor

ECU with built in MAP sensor

Coolant temperature sensor

Programmed Ignition Programmed Ignition

Another variation of controlling Another variation of controlling the ignition is a system called the ignition is a system called

programmed ignition. programmed ignition. Programmed ignition systems Programmed ignition systems

are also operated by a computer are also operated by a computer (ECU). (ECU).

This system has several This system has several ………………… over the basic ………………… over the basic

distributor systems. distributor systems.

Advantages

The ……………… timing can be The ……………… timing can be altered to accurately match a altered to accurately match a

wide range of engine ………… wide range of engine ………… and ………… conditions, which and ………… conditions, which are stored inside the memory of are stored inside the memory of

the ………… using what is the ………… using what is known as ‘maps’. known as ‘maps’.

Ignition

Speed

Load

ECU

The illustration below shows the The illustration below shows the components used in a programmed ignition components used in a programmed ignition

system; name the numbered components.system; name the numbered components.

1 – ECU

2 – coolant temp. sensor

3 – knock sensor

4 – crank sensor

5 – coil

6 – ignition switch

7 – distributor

Questions Questions

1. What is different about the DIS coil?

2. What happens to the wasted spark?

3. What is the reluctor ring?

4. What is the function of the knock sensor?

5. What is the function of the crankshaft sensor?

6. What ignition component is replaced by the DIS coil?.

Answers Answers

1. It produces two sparks at the same time2. The wasted spark is introduced into the

cylinder on the exhaust stroke, it is wasted3. A reluctor ring is what excites an inductive

sensor4. The knock sensor, senses knocks in the

cylinder caused by pinking, then signals the ECU to retard the timing

5. Tells the ECU the speed and position of the crankshaft

6. The distributor