EZK Ignition System With Tach and Timing Socket

EZK Ignition System W/Tach And Timing Socket Diagrams:

EZK Ignition System W/Tach And Timing Socket Components:

Locations of components

1 Battery
In the engine compartment on the right-hand side

3 Earthing point
In the facia

4 Starter motor
On the left-hand side of the engine (intake side)

5 Ignition coil
On the cross-member above the radiator

6 Ignition distributor
At the front of the engine

7 Earthing point
On the radiator cross-member

22 Fuse box
In the electrical distribution box in the engine compartment, on the left-hand wheel housing

47P CHECK ENGINE warning lamp
In combined instrument 47 in the instrument panel

57 3-pole connector
In the engine compartment, on the right-hand side, at the air intake

59 2-pole connector
In the engine compartment, on the right-hand side, at the air intake

60 Single-pole connector
In the electrical distribution box in the engine compartment, on the left-hand wheel housing

67 6-pole connector
In the engine compartment, on the right-hand side, at the air intake

73 Timing service instrument socket (TSI socket)
In the electrical distribution box in the engine compartment, on the left-hand wheel housing

75 Distribution block
In the engine compartment, on the right-hand side

110 Tachometer
In combined instrument 47 on the instrument panel

145 Test tapping, EZK
In the engine compartment, on the left-hand wheel housing, forward of the electrical distribution box

146 Amplifier for electronic ignition system
In the engine compartment, forward of the left-hand wheel housing

147 Ignition pulse amplifier
In the electrical distribution box in the engine compartment, on the left-hand wheel housing

152B 29-pole red connector
In the electrical distribution box in the engine compartment, on the left-hand wheel housing. The connector is accessible from the interior of the car

157 Spark plugs
On the engine

158 Negative distribution terminal
In the electrical distribution box in the engine compartment, on the left-hand wheel housing

159 Distribution terminal +15
In the electrical distribution box in the engine compartment, on the left-hand wheel housing

176 Control unit for EZK ignition system
In the engine compartment, forward of the left-hand wheel housing

178 Knocking sensor for the APC/EZK system
On the engine, between the two centre intake ports

200 Control unit for the LH system
Forward of the right-hand front door, below the facia (behind the trim)

201 Engine earthing point
At the engine lifting lug

203 Throttle angle transmitter - LH system
On the throttle housing

204 Test connector - LH system
In the engine compartment, behind the right-hand wheel housing

Operation
The EZK ignition system is fitted on 1986 models with 16-valve engines without turbocharger. This breaker- less ignition system is equipped with a Hall sensor. It is controlled by a knocking sensor, which permits the highest possible engine performance on each grade of fuel. This provides good fuel economy and cleaner exhaust gases.

When the ignition switch is in the start or drive position, +15 is supplied to ignition coil 5, amplifier 146 and EZK control unit 176.

Control unit 176 receives ignition pulses via a shielded cable from the Hall sensor in ignition distributor 6. The frequency of the pulses is equivalent to the engine speed. The control unit then adjusts the timing in accordance with the following factors:

engine speed
engine load
any knocking tendencies

The pulses supplied from terminal 16 of the control unit are amplified and adjusted in amplifier 146. A high-tension pulse is generated in the secondary winding each time a pulse breaks the primary circuit of the ignition coil. The high-tension pulse is then supplied to the corresponding spark plug (157) via distributor 6.

The ignition is set at 50 when the engine is started. This ignition setting is dependent on the speed of the engine, and starts at around 700 rpm. It is adjusted in accordance with the values stored in the control unit. (The distributor has no centrifugal or vacuum advance mechanisms.)

Fuel system control unit 200 provides the ignition system with information on the engine load. Throttle angle transmitter 203 is connected (earthed) when the butterfly valve is closed, i.e. when the engine is idling. When the load exceeds the value stored in the control unit, the timing will be retarded by around 60 on all cylinders. The timing returns to normal in steps of around 10 after the load has ceased to increase.

The control unit receives information on knocking in any of the cylinders via knocking sensor 178. The timing is then retarded on the knocking cylinder only, in steps of around 30 This will continue until the knocking ceases, or until the timing has been retarded by a total of around 130. The timing returns to normal in steps of 0.35°.

EZK test connector 145 is intended for special test equipment. Terminal 13 of the control unit delivers a pulse for each knock detected. (Positive voltage is supplied to the connector when the ignition switch is in the drive position.)

Should a fault occur in the control unit, a signal (earth) will be delivered from terminal 3, which will cause CHECK ENGINE warning lamp 47P to flash. (This lamp can also be activated by the fuel injection system.)

Ignition pulse amplifier 147 has been introduced to provide more accurate control of the systems which are dependent on ignition pulses, such as the fuel system and the APC system.

Ignition pulses are supplied from terminal 16 of the control unit to the TD-I input of ignition pulse amplifier 147. A "pure" 12 V square-wave pulse is then supplied from the TD-0 output of the amplifier to timing service instrument socket 73, tachometer 110 and other systems that are dependent on ignition pulses.

Tachometer
Tachometer 110, located in combined instrument 47, is supplied across fuse 7 and the red 29-pole connector 152B. The control pulses required for displaying the engine speed are supplied from ignition pulse amplifier 147.

Timing service instrument socket
Timing service instrument (TSI) socket 73 is intended for a special ignition service instrument and has the following terminals:

1. Positive supply direct from battery 1

2. Earth

3. Solenoid (terminal 50) of starter motor 4

4. Positive supply from the ignition switch when the latter is in the start or drive position

5. Ignition pulses from ignition pulse amplifier 147

6. Not used

Fault-tracing hints
As a general rule, the connector to the control unit should always be disconnected when measurements are made on the ignition system cable harness. Use an ohmmeter not a buzzer.

The ignition system will be energized when the ignition switch is in the drive position.

1. Check that terminal 15 of the ignition coil and terminal 4 of the timing service instrument socket are live.

2. Check that terminal 4 of amplifier 146 and terminal 6 of control unit 176 are live.

3. Tachometer: Check fuse 7 first and check that the supply to it is live. Check that terminal 3 of the circuit board for tachometer 110 is live, and that ignition pulses are being supplied from ignition pulse amplifier 147.

4. Ignition pulse amplifier: Check fuse 22, and check that terminal 15 of the ignition pulse amplifier is live, and that ignition pulses are being supplied from the amplifier output. (Measure in the TSI socket.)

5. Check all connectors, cable harnesses and earth connections.