Bridgwater College

Electronic Ignition - Programme Ignition Bridgwater College

PROGAMME IGNITION SYSTEM PROGRAMME IGNITION PART I

PROGRAMMED INGNITION WITH KNOCK CONTROL PROGRAMME IGNITION SYSTEM COMPONENTS 9 12 10 2 4 6 1 3

PROGRAMME IGNITION WIRING Please complete your handout by drawing in the missing wires and the names of each of the system components. You will see a number of wires appear on the next set of screens.

PROGRAMMED INGNITION WITH KNOCK CONTROL 2 1 9 12 10 2 4 6 1 3 8 9 4 3 1 2 3 4 5 6 7 8 9 5 6 7

PROGRAMMED INGNITION WITH KNOCK CONTROL 2 1 9 12 10 2 4 6 1 3 8 9 4 3 1 BATTERY 2 IGNITION SWITCH 3 IGNITION COIL 4 ECU 5 6 7 8 9 5 6 7

PROGRAMMED INGNITION WITH KNOCK CONTROL 2 1 9 12 10 2 4 6 1 3 8 9 4 3 1 BATTERY 2 IGNITION SWITCH 3 IGNITION COIL 4 ECU 5 CRANKSHAFT SENSOR 6 7 8 9 5 6 7

PROGRAMMED INGNITION WITH KNOCK CONTROL 2 1 9 12 10 2 4 6 1 3 8 9 4 3 1 BATTERY 2 IGNITION SWITCH 3 IGNITION COIL 4 ECU 5 CRANKSHAFT SENSOR 6 KNOCK SENSOR 7 8 9 5 6 7

PROGRAMMED INGNITION WITH KNOCK CONTROL 2 1 9 12 10 2 4 6 1 3 8 9 4 3 1 BATTERY 2 IGNITION SWITCH 3 IGNITION COIL 4 ECU 5 CRANKSHAFT SENSOR 6 KNOCK SENSOR 7 COOLANT ‘TEMP’ SENSOR 8 CHOKE ECU 9 CHOKE ECU 5 6 7

PROGRAMME IGNITION INTRODUCTION This system incorporates standard constant energy features, except timing is controlled using digital electronic techniques, instead of the conventional mechanical and vacuum advance. An electronic control unit (ECU) determines the correct ignition timing by receiving information from the following sensors:- 1. Crankshaft sensor (Crankshaft position and engine speed) 2. Temperature sensor (Coolant temperature) 3. Knock sensor (Combustion detonation ‘pinking’) 4. Carburetor vacuum pipe (engine load) A major advantage of this system is a knock sensing facility, enabling the engine to run close to it’s limits of ignition advance. This improves efficiency, without detonation occurring.

RELUCTOR DISC RELUCTOR DISC Secured to the flywheel. The disc contains a number of teeth spaced at 10 degree intervals, however there are two positions 180 degrees apart where teeth are missing, these positions will inform the computer TDC No 1 and 4 cylinders. The missing teeth will provide basic ignition timing and all the other teeth will inform the ECU crankshaft position and engine speed. MISSING TEETH 180 DEGREES A PART TO IDENTIFY TDC, CRANKSHAFT POSITION AND ENGINE SPEED STARTER RING GEAR RELUCTOR TEETH

KNOCK SENSOR The knock sensor is a piezo electric accelerometer which produces an output voltage, to the ECU proportional to the sensed vibration. This vibration is produced by general mechanical noise and combustion detonation. Sophisticated electronic processing is used to recognized the latter from mechanical noise. The sensor will inform the ECU that a knock has been detected. For example the knock could have been detected from No1 cylinder, the ECU will note the knock, and on a 4 cylinder engine it will count 4 firing pulses, this will then be back to the cylinder with the knock, the ECU will retard the ignition timing by 5 degrees until the knock is eliminated. The ECU will then advance the timing for that same cylinder in steps of 0.625 degrees every 8 engine revolutions.

KNOCK SENSOR VM 1 0

KNOCK SENSOR VM 1 0 . KNOCK

KNOCK SENSOR VM 1 0 .

KNOCK SENSOR VM 1 0 . KNOCK

KNOCK SENSOR VM 1 0

COOLANT TEMPATURE SENSOR Coolant temperature correction This function is provided to ensure optimum driveability at low temperatures by either advancing or retarding the basic ignition and the data is stored subject to a load correction value below +70 degrees C coolant temperature.

CRANKSHAFT SENSOR The crankshaft sensor contains a magnet and a coil of wire when the reluctor teeth pass the sensor an AC pulse of electricity is produced an d this pulse is passed to the ECU. The next few screens will simulate it’s operation. 0 _ + Reluctor tooth is approaching the crankshaft sensor

ELECTRONIC CONTROL UNIT This unit consists of a plastic case which contains the electronic components mounted on a printed circuit board. All connections are via a 12 pin plug and socket assembly which are protected against short circuit and reverse polarity. The ECU has three main functions:- 1. To control ignition timing electronically using information received from the crankshaft sensor (engine speed and position), inlet manifold depression (engine load), knock sensor and coolant temperature sensor. 2. To provide a constant energy drive to the ignition coil, controlling both coil on and off. 3. a) Provide flat ignition timing for idle speed control on vehicles equipped with fuel injection. b) Provide an output for a turbo boost gauge. c) Provide an output for a coolant temperature gauge on vehicles without automatic choke control.

MAPPED IGNITION TIMING The computer memory MAP will store information for advancing and retarding the ignition timing according to engine speed and load IGNITION ADVANCE IGNITION RETARD SPEED LOAD

PROGAMMED INGNITION WITH KNOCK CONTROL V1 9 12 10 2 4 6 1 3 8 9 V2 ENGINE CRANKING

PROGAMMED INGNITION WITH KNOCK CONTROL V3 9 12 10 2 4 6 1 3 8 9 V4 OHM

DIAGNOSTICS With an increase in vacuum the ignition should advance STROBE CRANKSHAFT PULLEY VACUUM PUMP

STROBE CRANKSHAFT PULLEY VACUUM PUMP

PROGAMME IGNITION SYSTEM PROGRAMME IGNITION PART II

PROGAMME IGNITION WIRING FOR LATER MODELS WITHOUT KNOCK CONTROL Please complete your handout by drawing in the missing wires and the names of each of the system components. You will see a number of wires appear on the next set of screens.

PROGRAMME IGNITION SYSTEM LAYOUT 11 10 15 30 25 30 20 33 31 32 13 14 29

PROGRAMME IGNITION SYSTEM LAYOUT 14 3 1 2 11 10 15 30 7 25 30 20 33 31 32 13 14 29 4 11 1 2 3 4 5 6 7 8 9 10 11 12 13 14 7 6 8 5 10 13 12

PROGRAMME IGNITION SYSTEM LAYOUT 14 3 1 2 11 10 15 30 7 25 30 20 33 31 32 13 14 29 4 11 1 FUSIBLE LINK 2 FUSE No 1 10A 3 IGNITION SWITCH 4 BATTERY 5 6 IGNITION COIL 7 ECU 8 9 10 11 12 13 14 7 6 8 5 10 13 12

PROGRAMME IGNITION SYSTEM LAYOUT 14 3 1 2 11 10 15 30 7 25 30 20 33 31 32 13 14 29 4 11 1 FUSIBLE LINK 2 FUSE No 1 10A 3 IGNITION SWITCH 4 BATTERY 5 REV-COUNTER 6 IGNITION COIL 7 ECU 8 9 10 11 12 13 14 7 6 8 5 10 13 12

PROGRAMME IGNITION SYSTEM LAYOUT 14 3 1 2 11 10 15 30 7 25 30 20 33 31 32 13 14 29 4 11 1 FUSIBLE LINK 2 FUSE No 1 10A 3 IGNITION SWITCH 4 BATTERY 5 REV-COUNTER 6 IGNITION COIL 7 ECU 8 FUEL PUMP RELAY 9 10 11 12 13 14 7 6 8 5 10 13 12

PROGRAMME IGNITION SYSTEM LAYOUT 14 3 1 2 11 10 15 30 7 25 30 20 33 31 32 13 14 29 4 11 1 FUSIBLE LINK 2 FUSE No 1 10A 3 IGNITION SWITCH 4 BATTERY 5 REV-COUNTER 6 IGNITION COIL 7 ECU 8 FUEL PUMP RELAY 9 10 CRANK ANGLE SENSOR 11 12 13 14 7 6 8 5 10 13 12

PROGRAMME IGNITION SYSTEM LAYOUT 14 3 1 2 11 10 15 30 7 25 30 20 33 31 32 13 14 29 4 11 1 FUSIBLE LINK 2 FUSE No 1 10A 3 IGNITION SWITCH 4 BATTERY 5 REV-COUNTER 6 IGNITION COIL 7 ECU 8 FUEL PUMP RELAY 9 10 CRANK ANGLE SENSOR 11 DIAGNOSTIC SOCKET 12 13 14 7 6 8 5 10 13 12

PROGRAMME IGNITION SYSTEM LAYOUT 14 3 1 2 11 10 15 30 7 25 30 20 33 31 32 13 14 29 4 11 1 FUSIBLE LINK 2 FUSE No 1 10A 3 IGNITION SWITCH 4 BATTERY 5 REV-COUNTER 6 IGNITION COIL 7 ECU 8 FUEL PUMP RELAY 9 10 CRANK ANGLE SENSOR 11 DIAGNOSTIC SOCKET 12 THROTTLE PEDAL SWITCH 13 14 7 6 8 5 10 13 12

PROGRAMME IGNITION SYSTEM LAYOUT 14 3 1 2 11 10 15 30 7 25 30 20 33 31 32 13 14 29 4 11 1 FUSIBLE LINK 2 FUSE No 1 10A 3 IGNITION SWITCH 4 BATTERY 5 REV-COUNTER 6 IGNITION COIL 7 ECU 8 FUEL PUMP RELAY 9 TO DISTRIBUROR 10 CRANK ANGLE SENSOR 11 DIAGNOSTIC SOCKET 12 THROTTLE PEDAL SWITCH 13 COOLANT ‘TEMP’ SENSOR 14 MAP SENSOR 7 9 6 8 5 10 13 12

DIAGNOSTICS V1 V2 11 10 15 30 25 30 20 33 31 32 13 14 29 V3

DIAGNOSTICS 11 10 15 30 25 30 20 33 31 32 13 14 29 SCOPE

DIAGNOSTICS 11 10 15 30 25 30 20 33 31 32 13 14 29 OHM

PROGRAMME IGNITION COMPLETE

1 2 11 10 15 30 25 30 20 33 31 32 13 14 29 4

Bridgwater College