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At first it was going to be very uncomfortable when i was told i was doing e-learning and kind of lost interest after a bit but then i got the hang of it and now i like it as for the course it is fun and i have learned alot from rob humphreys so i wish all those who are still partaking in the course and i hope you all enjoyed it like i did

Diesel

Who invented the diesel engine and when?

 The first diesel engine was invented by Rudolf Diesel in 1892. The German inventor's invention was subsequently named for its inventor.

What fuel pressure would you get from a diesel pump?

The pressures you would usually get in a diesel pump is 10,300 to 20,700 Kpa.

How does the diesel pump and why do we need to time the pump?

A diesel pump's full name is a diesel injection pump, and like the name suggests, is responsible for injecting fuel into the firing cylinders of diesel engines. It is important to remember that, unlike gasoline-powered engines, diesel engines do not use spark plugs to ignite the fuel in the firing cylinders. They rely entirely on the high compression pressure of the fuel in the cylinder to result in combustion. As a result, diesel injection pumps are extremely important and must be built tough to produce the compression rates of up to 15,000 psi necessary for the engine's functioning. Distributor diesel injection pumps are also called rotary injection pumps. They are comprised of a hollow cylinder called a rotor as it sits on a cam which connects to the ports of the distributor head. The rotor sits between the firing cylinders in the engine block, and has a small hole in one side. Unlike a gas engine, this distributor is more similar to a carburetor in that it pushes blasts of fuel through to the rotor in time with the rise and fall of the engine's pistons. Sitting on a cam as it is, the rotor turns toward the firing cylinder when it's about to fire, aligns its hole with the port on the side of the cylinder, and sprays in the fuel just in time for the combustion, before turning again toward the next cylinder to repeat the process.

How do you time the pump and with what equipment would you use?

First you would mark up the flywheel that way when it is being is being dismantled you wouldn’t have to worry about it. Then you put all your focus on the camshaft and the position it is in and make sure that it is carefully dismantled from the diesel pump. Equipment  I would use is Socket set for bolts and screw driver set for hard to reach places and a spanner set for places that socket set can’t reach.
 
What is the purpose of a glow plugs and how do you test the circuit?

Some engines don’t use spark plugs so they use glow plugs to heat the fuel and air mixture as the stroke is going on the glow plugs start to heat up and in that a starting  a combustion pushing the piston down. How you check glow plugs is first remove them from the engine and using a 12v battery and jumper lids, check that the glow plugs tips glow and be careful not to touch them for it’s really hot. That’s how you check a glow plug but first remember to visually inspect and write down what you see.

Why do we need a lift pump on diesel engine?
It is needed because it helps control the flow of diesel going into the engine not only that it also filters the diesel going in.

Why do we need an electronic fuel shut of valve?

Fuel valve shut off is needed to instantly shut off valve or stop flow of fuel in case of valve or electrical failure.

What is the knock sensor for and where is it situated?

Lets the engine run the ignition timing to the advanced it can go. The knock sensor detects pinging , When this happens the ECU retards the ignition timing just enough to stop the pinging. It is usually located on top of the engine block by the intake manifold. Lets the diesel engine run the ignition in advance so it can adjust or warm-up.

How does the diesel injector work?

The diesel injector is a line distributor pump and takes in fuel with the aid of the lift pump and the pumped pressure is around 4-10Psi.The fuel will flow at a high pressure into the injector tube of the pump and then the injectors spray fuel into the cylinder block to create a combustion.

Why do you need to bleed a diesel engine after replacing a fuel filter or removing the pump?

It’s important to let any existing fuel or air left in the fuel lines out or else your vehicle may have problems starting and may damage your starter motor and flatten your battery.

How do you bleed the system?

Pump the primer and then unscrew the fuel lines just enough for the fuel to get out, then turn the engine over just until you see leak(fuel) at the base of the lines where they are screwed on. Now screwed back on use a cloth or rag to clean excess fuel.

 
How does a turbo work?

A turbo can significantly boost an engine's horsepower without significantly increasing its weight, which is the huge benefit that makes turbos so popular! the turbocharger uses the exhaust flow from the engine to spin a turbine, which in turn spins an air pump. The turbine in the turbocharger spins at speeds of up to 150,000 rotations per minute (rpm) -- that's about 30 times faster than most car engines can go. And since it is hooked up to the exhaust, the temperatures in the turbine are also very high.

What is a supercharger?

A supercharger is an air compressor that sends pressurised air through the intake system to the engine. This also a way to increase power, torque. The downside to the super charger is that the engine powers the super charger itself with a belt so you lose a lot of horse power this is known to be a small parasitic effect.

What’s the difference between a turbo and supercharger?

Well the turbo use exhaust gas requiring better cooling and the supercharger just suck air straight in.

Why do we need a after- cooler or inter-cooler fitted to a diesel engine?

These are a cooling system commonly used with turbo's because of the extremely hot gases generated.
the after cooler is often the last cooling process before the end stage of the cooling before it enters the engine.
Without these your engine would sustain extreme damage and be very dangerous. Hot air expands and that means the engine would get less air so running the air through this make the air more dense. An intercooler is designed for this so is more effective over a normal radiator. These are needed because of the extremely hot gases created by the turbo charger. Also the after cooler

What the difference between  in a direct-injection ( DI,) an indirect-injection ( IDI)?

The layout of the injection system. The indirect injection system has a small swirl chamber above the cylinder where the fuel is injected. The direct injection system has the injection nozzle fixed to the top of the combustion chamber

What is the purpose of a governor?

The go keeps the engine from running faster than the set rate.

What is the difference between a diesel and a common rail diesel?

Common rail: A common fuel pressure rail that feeds all injectors. Common rail is able to supply fuel over a wider range of injection timing and pressure. This is controlled by a solanoid and a computer

FUEL INJECTION

ECU- Electronic control unit?

The ELECTRONIC CONTROL (ECU) is the generic term for embedded system that controls more of the electrical systems then the subsystems in the motor vehicle. There are quite a few a names for the ECU, INCLUDE ECM electronic control module, CCM central control module, and sometime referred to the vehicle computer and controls most if not all the electrical components.

Mass air flow sensor?

A mass air sensor can also be known as air flow sensor and is a component of the fuel injection engine and its function is to measure the amount of air entering the engine , also is a component electronic fuel injection system of a modern automotive vehicle.

Air Temp sensor?

The Air Temp. Sensor is used to measure the temperature of the engine coolant as the temperature changes constantly, and the information the sensor got was monitored by the ECU and then could control the different ignition, how much fuel and control functions, if needed turn on or off the cooling fan.

TPS throttle position sensor?

A throttle position sensor (TPS) this sensor is used to keep track of the position of the throttle in an combustion engine. The sensor is located on the butterfly spindle so it can easily and directly measure and know the position of the butterfly throttle valve. The sensor the is usually if not always a potentiometer and therefore provides a constant resistance depending on the position of the valve and by that also knowing the throttle position.

Throttle body?

In fuel injected engines, the throttle body is apart of the air intake system that controls the amount of air flowing thru the engine, in response to the acceleration pedal being pressed. The throttle body is found between the air filter box and the intake manifold, and it is mostly attached to or close to the mass air flow sensor. The acceleration pedal of many cars the motion of this pedal is communicated thru the throttle cable, so it could activate the throttle linkages, which move the throttle plate. Cars with electric throttle control or better known as Drive-By-Wire, the electric motor controls the throttle links and the accelerartor pedal is nt connected to the throttle pedal but your sensor. Which sends the position of the pedal to the ECU and then the ECU determines the throttle opening based on the position of the pedal and inputs of other sensors.

Temp sensor?

An air temperature sensor are found in and used on fuel injected engines. The function of this sensor is to help the computer or ECU calculate air density. The slightest change in temperature changes the resistance of the sensor, the higher the temperature the less dense it becomes. As the air gets less dense so the computer picks that up and starts to lessen the fuel flow. If fuel is not lessen the engine might get rich, and loss power and taking in more fuel. The air temp. sensor is found in the air inlet tupe.

fuel rail?

Fuel rail is commonly a pipe. Used to control the flow of fuel that is given to each individual fuel injector on a combustion engine. It’s design is to have a pocket for each injector as well as an inlet valve for the fuel to flow in, some fuel rails are incorporate an fuel pressure regulator. Fuel rails are used in engines with multi-point fuel injection systems, even though there a couple engines that still use fuel distributor with individual pipes to injectors.

Fuel pressure regulator?

A Fuel pressure Regulators main job is to keep constant watch over the pressure of the fuel and keep it constant pressure. The fuel pressure regulator is in control of the set fuel pressure of the system.

Injectors?

Injectors are Found in automotive vehicles also with a ECU system. All the fuel injectors are supplied by the fuel rail and then fuel is sprayed with a high pressure into the cylinder head, also injectors replace carburettors because of the changes in emission.

Idle air control?

The idle air control  is electrically operated valve that allows air to get pass the throttle plate, In most fuel injected engines it must regulate the engine idle speed.

O2 sensor ( lambda sensor)?

The O2 sensor is found in the exhaust manifold, is used by the ECU to regulate the oxygen levels in order to adjust fuel ratio.

Map sensor?

The Manifold Pressure sensor (MAP) is one of the sensors used by the ECU system and an internal combustion engine. Most vehicle’s that use MAP are fuel injected. The MAP sensor gives instant pressure readings and information gathered by the MAP is given to the cars ECU system. Then the information is used to determine air density and the engines air mass flow rate,  and then Knows the required fuel for the best combustion. 

References:
www.google.com/images
www.visualdictionary.com
www.ask.com

CARBURETTOR

How does the carb work?
It is a component in which it controls the flow of fuel, air and oil and makes sure the right amount is flowed into the cylinder even though they enter different points it is still controlled by the carburetor. Also when the mixture is in the cylinder it is pushed up by the piston then when the spark plug ignites causing the engine to fire.

What is the purpose of the float in the carburetor ?

The purpose of the float is  to control the airflow coming in and going out and being mixed and also because it is filled with fuel as the level of fuel increases and so does the float begin to restrict the air flow coming in and going out.

What is the purpose and how does  mechanical lift pump work?

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The purpose or main function of the mechanical lift pump is to pump the fuel from the fuel the fuel tank to the carburetor. This kind of pump has lever that is constantly hitting the lobes of the camshaft. The lever will go upward and downward as it hits the lobe as the camshaft rotates there by causing a vaccum effect within the pump.causing a low pressure in the supply line which causes fuel to be drawn up from tank to carb.

What pressures would you get from this type of pump?
2-5 Psi

What does S.I mean ?
It means SPARK IGNITION

What does C.I. MEAN ?
It means COMPRESSION IGNITION

What is the FOUR STROKE CYCLE ?

WWW.VISUALDICTIONARYONLINE.COM/FOURSTROKECYCLE

INTAKE= Phase in which piston goes down the cylinder and at the same time the exhaust port is closed. so as piston is going down sucks in fresh air and fuel and mixes them together and prepares for nest phase.

COMPRESSION= The next phase of the four stroke cycle and the mixture is being pushed up with the movement of the piston moving upwards while the spark plug produces a spark.

COMBUSTION= In this phase the mixture has been ignited by the spark plug therefore pushing the piston down by that causing the camshaft to move.

EXHAUST= This phase is when the piston is moving back upwards to expel burnt air and fuel and in this process exhaust port is open and the and intake closed.

How does the emulsion tube work?

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The Emulsion Tubes control the fuel and air entering to the carburetor. When air enters the tube through the airjet and the fuel enters through the main jet this process emulsifies the fuel going into the carburetor. EMULSION TUBE has a certain amount of wholes from the top to the bottom which control the amount of fuel mixture being used. Also hole allow the air and fuel to enter the main circuit to emulsify the fuel.

How does a manual and automatic choke work?
The mannual choke is a device which are more commonly found on older boats and cars, bikes. Mannual chokes work by increasing thrust or throttle(revolutions) of the motor to get it to warm up, or a working tempreture and the choke must be pressured or pushed. As for the AUTOMATIC CHOKES same principal. But they don't rely on the person driving to push or pull the choke it is controlled automatically by thremostat.

How does a vacuum fuel pump work?
The vaccum pump is a device that uses the suckition of the piston strokes to pump fuel. It also works by using a diaphram

What is the difference between diesel and petrol ?
The difference between petrol and diesel is that petrol can easily start a fire with the smallest spark and is highly flammable. As for diesel it contains more oil and and takes more then a simple spark for it to ignite. Diesel has to be warmed up before ignited.

 Taking apart a carburetor

 Getting out the shaft

 Inspecting Float and main shafts