Automotive notes

1. FUEL DELIVERY AND
IGNITION SYSTEM

2. OBJECTIVES:
■ State the purpose of the fuel delivery system.
■ Discuss the components of fuel delivery system.
FUEL DELIVERY SYSTEM

3. FUEL DELIVERY SYSTEM
The fuel delivery system consists of all the components which
supply the engine with fuel. This includes the tank itself, all
the lines, one or more fuel filters, a fuel pump ( mechanical or
electric ), and the fuel metering components ( carburetor or
fuel injection system).

4. PURPOSE OF FUEL DELIVERY SYSTEM
The purpose of fuel delivery system is to deliver the proper
volume of the fuel at the correct pressure. When the fuel is
drawn by the pump from the fuel tank and passes through
the fuel filter into a high pressure line from where it flows to
the engine –mounted fuel/delivery pipe. The rail pipe
supplies the fuel to the injectors. A mechanical pressure
regulator mounted in the rail/pipe excess fuel to return to the
tank.

5. FUEL DELIVERY COMPONENTS:
■ FUEL TANK
■ FUEL PUMP
■ FUEL FILTERS
■ FUEL INJECTORS OR CARBURATOR

6. FUEL TANK
- Is the main storage for the fuel that runs the vehicle.
- The tank serves as the system RESERVOIR. It is sealed unit
that allows the natural gassing of the fuel to aid delivery to
the pump by slightly pressurizing the system.
- The tank has an electronic “trigger” that conveys
information concerning the amount of fuel to the gas
gauge.

7. FUEL PUMP
- Its purpose is to circulate the fuel thru the system and
pressurized it at the same time.
- Is mounted in the tank and is immersed in fuel. The
location of the pump helps reduce the noise produced by
electric fuel pump motor. It also keep the pump supplied
with fuel which lubricates and cools the pumps motor.
- Its primary function is to draw fuel from the tank and pump
it into the internal combustion engine. There are two kinds
of fuel pumps: mechanical and electric which are used in
vehicles with carburetors and electronic fuel injectors,
respectively.

8. FILTERS
- It is fixed in both the ends of the fuel pumps to separate
impurities from the fuel, Thereby ensuring optional engine
performance.
FUEL INJECTOR
- It is an electronic valve that opens/closes at regular
intervals to deliver the right amount of fuel to the engine.

9. CARBURETOR
- Its main purpose is to mix the right amount of air and fuel
to deliver it to the engine. The carburetor is the predessor
of the fuel injector.

10. IGNITION SYSTEM

11. WHAT IS IGNITION SYSTEM?
- The system in an internal-combustion engine that produces
the spark to ignite the mixture of fuel and air: includes the
BATTERY, IGNITION COIL, DISTRIBUTOR, SPARK PLUGS,
and associated SWITCHES AND WIRINGS.

12. IGNITION FUNCTIONS
■ Produces 30,000 volt spark plug.
■ Distributes high voltage spark to each spark plug in correct
sequence
■ Times the spark so it occurs as piston is nearing top dead
center
■ Varies sparks timing with load, speed, and other
conditions.

13. BASIC IGNITION SYSTEM
COMPONENTS
■ BATTERY
■ IGNITION SWITCH
■ IGNITION COIL
■ SWITCHING DEVICE
■ SPARK PLUG
■ IGNITION SYSTEM WIRES

14. IGNITION PARTS
BATTERY- provides power for system
IGNITION SWITCH- allows driver to turn ignition on and off
IGNITION COIL- changes battery voltage to 30,000V during normal
operation and has a potential to produce up to 60,000V.
SWITCHING DEVICE- mechanical or electronic switch that operates
Ignition coil ( pick-up coil, Crank sensor, Cam sensor).
SPARK PLUG- uses high voltage from ignition coil to produce an arc in
the combustion chamber.
IGNITION SYSTEM WIRES- connect components

15. BASIC IGNITION SYSTEM
• Battery supplies power to
entire system
• Ignition Switch turns engine
on or off
• Coil transform volts
• Switching device triggers
ignition coil
• Spark plug and wires
distribute spark

16. IGNITION COIL
• Transformer
• 2 sets of windings
> Primary windings
> Secondary Windings
• Iron core
• Produces magnetic field

18. IGNITION SYSTEM TYPES
■ Battery Ignition System
■ Magneto Ignition System
■ Distributor less Ignition System

19. BATTERY IGNITION SYSTEM
■ A battery ignition system has 6 or 12 volt battery charged
by an engine-driven generator to supply electricity, an
ignition coil to increase the voltage, a device to interrupt
current from the coil, a distributor to direct current to the
correct cylinder, and spark plug projecting into each
cylinder.
■ Current goes from the battery through the primary winding
of the coil, through the interrupting device, and back to the
battery.

20. The primary circuits consists of the battery, ammeter, ignition switch,
primary coil winding capacitor and breaker points.
The function of these components are:
■ BATTERY- Provided the power to run the system
■ IGNITION SWITCH- allows the driver to turn the system on and off
■ PRIMARY COIL- produces the magnetic field to create the high
voltage in the secondary coil
■ BREAKER POINTS- a mechanical switch that acts as the triggering
mechanism
■ CAPACITOR- protects the points from burning out.

21. The secondary circuits converts magnetic induction into high voltage
electricity to jump across the spark plug gap, firing the mixture at the
tight time. The function of the components are:
■ SECONDARY COIL- the part of the coil that creates the high voltage
electricity.
■ ROTOR- spin around on the top of the distributor shaft, and
distributes the spark to the tight spark plug.
■ SPARK PLUG- take the electricity from the wires and give it an air gap
in the combustion chamber to jump across to light the mixture.

23. MAGNETO IGNITION SYSTEM
● The simplest form of spark ignition is that using a magneto
● An ignition magneto, or high tension magneto is a magneto that
provides current for the ignition system of a spark-ignition engine, such
as petrol engine.
● The engine spins a magnet inside a coil, or in the earlier designs, a
coil inside a fixed magnet, and also operates a contact breaker,
interrupting the current and causing the voltage to be increased
sufficiently to jump a small gap.
● The spark plugs are connected directly from the magneto output.

26. DISTRIBUTORLESS IGNITION SYSTEM
The principles of the operation are basically no different than those for
distributor equipped electronic ignition systems that began appearing
on American automobiles in 1972.
There are 2 obvious differences:
 A DI system does nit have a mechanical distributor
 Most DI systems use one coil for every two spark plugs ( however
some systems have one coil pee cylinder i.e. BHW).

27. Distributorless Ignition System
In operation the only major difference is that DI systems fire all the
engines spark plugs in ONE crankshaft revolution, whereas the old
mechanical distributor type fires all plugs every TWO crankshaft
revolutions.
On all four strokes engines, equipped with out distributors require TWO
crankshaft revolutions (720 ⁰ travel) for the combustion to occur on
each cylinder.
On engines with an even number of cylinders, combustion occurs pin
half of the cylinders in the first revolution ( 360⁰ ) and in the other half
in the second half of the revolution. Each cylinder that has combustion
in the first revolution has a companion cylinder that fires 360⁰ apart
from it during the second revolution.

29. CONTACT POINT SYSTEM
• Distributor turns ½
engine rpm
• Distributor Cam
• Contact points
• Condenser
• Point Dwell ( Cam
angle)
• Basis for all System

30. IGNITION SYSTEM TROUBLE SHOOTING