Automotive Automotive Ignition Ignition SystemsSystems
Ignition System Ignition System PurposePurpose
Create a high voltage spark Create a high voltage spark Deliver the spark at correct timeDeliver the spark at correct time
HHoow w StStufuff f WWororksks . .cocomm
Ignition TimingIgnition Timing
BTDCBTDC ATDCATDC Engine RPMEngine RPM Engine LoadEngine Load Firing OrderFiring Order RetardRetard AdvanceAdvance
Firing OrderFiring Order
Firing OrderFiring Order
1,3,4,21,3,4,2
1,2,5,4,3,21,2,5,4,3,2
1,5,6,3,4,2,7,81,5,6,3,4,2,7,8
Firing OrderFiring Order
Ignition System CircuitsIgnition System Circuits
Primary CircuitPrimary Circuit (Low Voltage)(Low Voltage)
Ignition SwitchIgnition Switch ResistorResistor Coil Primary Coil Primary
WindingWinding Ignition ModuleIgnition Module Pick-up AssemblyPick-up Assembly
Secondary Secondary CircuitCircuit (High Voltage)(High Voltage)
Coil Secondary Coil Secondary WindingWinding
Coil WireCoil Wire Distributor Cap & Distributor Cap &
RotorRotor Plug WiresPlug Wires Spark PlugsSpark Plugs
Ignition Primary CircuitIgnition Primary Circuit BatteryBattery Ignition SwitchIgnition Switch ResistorResistor Coil WindingCoil Winding Ignition ModuleIgnition Module Pick-up AssemblyPick-up Assembly Low voltage sideLow voltage side
Ignition CoilsIgnition Coils
Step-up Step-up transformertransformer
Primary windingPrimary winding Secondary windingSecondary winding Uses electro-Uses electro-
magnetic induction magnetic induction to operateto operate
Magnetic field Magnetic field must be built up must be built up and then collapsedand then collapsed
Ignition CoilIgnition Coil High Voltage wireHigh Voltage wire + Battery+ Battery - ign module - ign module Primary WindingsPrimary Windings Secondary Secondary
WindingsWindings
Making & Breaking FieldsMaking & Breaking Fields
Ignition ModulesIgnition Modules
Old Systems Used Old Systems Used Breaker PointsBreaker Points
Modules Contain Modules Contain a Switching a Switching TransistorTransistor
Externally Externally MountedMounted
Distributor Distributor MountedMounted
Ignition Pick-up Ignition Pick-up AssembliesAssemblies
Can be mounted in one of five different locations:
#1 Distributor#2 Vibration Damper#3 Flywheel#4 Crankshaft#5 Camshaft
DistributorDistributor
A mechanical A mechanical timing devicetiming device
Drives off engine Drives off engine camshaftcamshaft
Can controls both Can controls both primary and primary and secondary circuitssecondary circuits
May contain May contain advance unitsadvance units
The Rotor at WorkThe Rotor at Work
Rotates around to Rotates around to DISTRIBUTE DISTRIBUTE voltage to each voltage to each spark plugspark plug
http://www.howstuffworks.com/ignition-system4.htm
Ignition Secondary Ignition Secondary CircuitCircuit
Coil WindingCoil Winding Coil WireCoil Wire Distributor Cap & Distributor Cap &
RotorRotor Spark Plug WireSpark Plug Wire Spark PlugSpark Plug
Distributor Cap & RotorDistributor Cap & Rotor
Cap fits on top of the Cap fits on top of the distributor housingdistributor housing
Made of lexon plasticMade of lexon plastic Has an index mark Has an index mark
for proper for proper installationinstallation
Rotor fits on top of Rotor fits on top of distributor shaftdistributor shaft
Also is indexedAlso is indexed
Spark Plug WiresSpark Plug Wires
Very high Very high resistance wire resistance wire 1000 ohms per 1000 ohms per inchinch
Mostly insulation Mostly insulation materialmaterial
Small conductor Small conductor materialmaterial
Must follow firing Must follow firing orderorder
Spark Plug PlacementSpark Plug Placement
Spark PlugsSpark Plugs
Shell w/threadsShell w/threads Ceramic insulatorCeramic insulator Center electrodeCenter electrode Side electrodeSide electrode Plug gapPlug gap Heat rangeHeat range Plug designationPlug designation
Resistor PlugsResistor Plugs
Heat Rages of PlugsHeat Rages of Plugs
The difference between a "hot" and a "cold" spark plug
is in the shape of the ceramic tip.
The difference between a "hot" and a "cold" spark plug is in the shape of the ceramtip.
The carmaker will select the right-temperature plug for each car. Some cars with high-performance engines naturally generate more heat, so they need colder plugs. If the spark plug gets too hot, it could ignite the fuel before the spark fires; so it is important to stick with the right type of plug for your car.
Spark Plugs tell a storySpark Plugs tell a storyNormal Worn Lead Erossion Insulator Breakage
Minor Melting
Over HeatingCarbon
Fuel/Additive Deposits
Lead FouledLead Fouled Oil
Old Breaker Point Old Breaker Point IgnitionIgnition
Used 1920’s - Used 1920’s - 19741974
mechanical switch mechanical switch in distributor in distributor
build-up - collapse build-up - collapse coil magnetic fieldcoil magnetic field
Points wear out Points wear out Must be replaced Must be replaced
each yeareach year
Breaker Point (dwell Breaker Point (dwell angle)angle)
Breaker Point PartsBreaker Point Parts
Making & Collapsing fieldMaking & Collapsing field
Electronic Ignition with Electronic Ignition with Distributor (HEI)Distributor (HEI)
1970’s1970’s Transistor in Transistor in
ignition module ignition module turns coil on/ offturns coil on/ off
Module mounted Module mounted externally or in externally or in distributordistributor
Pick-up in Pick-up in distributordistributor
High Energy Ignition (HEI)High Energy Ignition (HEI)
Trigger Trigger WheelWheel
No PointsNo Points Rotating Reluctor Rotating Reluctor
WheelWheel Fewer Tune-UpsFewer Tune-Ups More EfficientMore Efficient
Optical Trigger (Chrysler)Optical Trigger (Chrysler) Photo Electric Photo Electric
SensorSensor (Photo = Light)(Photo = Light)
CKPSCKPS (crankshaft position (crankshaft position
sensor)sensor) Fewer PartsFewer Parts No PointsNo Points No DistributorNo Distributor No RotorNo Rotor Computer Computer
ControlledControlled More EfficientMore Efficient
Crank Trigger WheelCrank Trigger Wheel
Direct IgnitionDirect Ignition
No DistributorNo Distributor One Coil for Two One Coil for Two
CylindersCylinders Waste Spark Waste Spark
SystemSystem One Plug Fires One Plug Fires
BackwardsBackwards
Wasted SparkWasted Spark
11stst plug fires plug fires forwardforward
22ndnd fires fires backwardsbackwards
Sister cylindersSister cylinders
Direct IgnitionDirect Ignition
Coil OverCoil Over
Business End of the Business End of the Ignition SystemIgnition System
SizeSize ReachReach Heat RangeHeat Range Spark.Air GapSpark.Air Gap
Ignition System Ignition System MaintenanceMaintenance
Replace Spark Plugs every Replace Spark Plugs every 30,000mi/36mo30,000mi/36mo
Inspect Cap and Rotor (replace if Inspect Cap and Rotor (replace if necessary)necessary)
Inspect Spark Plug wires (replace if Inspect Spark Plug wires (replace if necessary)necessary)
Check Firing OrderCheck Firing Order Check Ignition Timing (if necessary)Check Ignition Timing (if necessary)
TimingTiming
Engine WarmEngine Warm At IdleAt Idle Defeat AdvanceDefeat Advance #1 Plug wire#1 Plug wire