Fuel Injection part1

Need to find out the purpose and how they work of the following components...

ECU - electronic control unit

The ECU is an electronic unit that controls all things electronic in your engine from how much fuel is being injected to ingnition timing. They are connected to all sensors such as ones below. It then absorbs all that information and makes the car run to the best of its ability with things such as fuel effinacy and firing times.


Mass air flow sensor?

Differant types of mass air flow sensors

This sensor is there to measure how much air is goin into the cylinder so that the ECU can then deliver the correct amount of fuel into the cylinder with the air. All these sensors have a built in intake air temputure senor which is also there to help work out an acurate reading of the mass air flow.


Air Temp sensor?
http://www.youtube.com/watch?v=dM4zUa9-Ib4&feature=fvwrel here is a video that describes the operation of  the Air Temp sensor. The purpose of an air temperature sensor is to help the computer calculate air density. A change in temperature changes the resistance in the sensor. Simply stated, the higher the air temperature gets the less dense the air becomes. As the air becomes less dense the computer knows that it needs to lessen the fuel flow.


TPS - throttle postion sensor?
http://www.youtube.com/watch?v=vyxNLrCMk3I here is a video the explains how a TPS works and a few of the advantages and disadvantages. This sensor is there to moniter the position of the throttle. the sensor is usally a potentiometer (three terminal resistor with a sliding contact which creates a adjustable voltage divider) which provides a variable resistance depending on the position of the valve.

 

Throttle body?

In older engines the throttle body is the body of the carb which has all the air flow go through. In fuel injected engines it is part of the air intake system which controls the amount of air going into your engine.