TTEC4843 :- FUELS AND FUELS SYSTEM

                TTEC4843:- EFI OFF CAR

CLEANING INJECTORS:-
In this we learned how to check and clean electronic fuel injectors.

• Their were 4 injectors .
• Then we listened each injector with stethoscope while the engine is running..all were audible,so all good.
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*Then we expose the wiring into the back of the injector plug, we take one injector at a time  and connect an LED checker ,then record if the light flashes.

• All 4 LED indicates the pulse present.

*Now, checked the injector operation by the engine speed.

•  yes , there was a 1000rpm drop during a single disconnect of injector.

*Also checked the resistence of each injector winding with the ignition off.

• all 4 winding resistance was 15.4 ohms. 
• So all good as under specification ( 12-16ohm)

*off car injector testing

• we performed it on all the 4 injectors we fitted them into the testing machine and checked for the injectors.
• check if  all fitting are secure before mounting them in the test machine.

*specification:-

• injector leakage:- 1drip per minute.
• injector flow rate 220cc per minute flow rate at 3.0 hz.

All 4 injector need intention=spray pattern flow rate not good fr all 4 injectors and where as injector leakage was also there.
*clean them or replace.

Important Note: 

• when replacing fuel injector do not forget to, replace all top "o" rings and lower "o" rings.
• Ensure injector seals and "o" rings are lubricated and injectors correctly located.
• And all fuels lines and connections  are correctly located without leaks.
  

AIR FLOW METER RESISTANCE TEST - FUEL INJECTION DIAGNOSIS:-

In todays task we checked the resistance on the air flow meter using ohms meter by checking the potentiometer circuits and determine the air flow sensor condition by comparing the result with the manufacturing specification.

• first thing we did was tested E1-FC closed had reading of infinty
• E1-FC open  0.2ohms

And it shows if the fuel pump relay is effected on pump operation with high resistance across the two terminals, this will not give right measurement and amount of fuel.
*As higher is the resistance so lower will be the voltage and fuel pump relay wont get enough current to open the fuel pump.

*AALL OTHER SENSORS HAS BEEN DISCUSED IN REPORT

AIR FLOW/MASS SENSOR TESTING:

• we started by looking for the air flow sensor on the outside of air cleaner.
• it is bolted to the air cleaner with the ducting connected to the throttle body.
• it could be in following shape:L type moving vane,hot wire ,sliding piston(mazda,ford), Karman voltex air pulse (mitsubishi) etc.

*the one we detected was L type moving vane.

*we need to have multikmeter ,heat gun and heat reader laser gun.

Acc. to the stated procedure the sensor could not meets the specification and can not be repaired

AIR TEMPERATURE SENSOR:We tested the air temperature sensor and using multimeter check sensor resistance.

Terminal no.             Tempersture               Reading                      Specification  
E2-THA                       20*C                           2130                            2000-3000 ohm
                                     60*C                           120                                 400-700  ohm






THROTTLE POSITION SENSOR (LINEAR TYPE): LINEAR TYPE IS THE ONE WHICH SENDS READING EVEN WHEN THE BUTTERFLY IS MOVING FROM  CLOSE TO OPEN OR OPEN TO CLOSE

• We check that the throttle leakage move smoothly.
• Check for the vaccum with your fingers at N port while engine start.
•  inspect throttle position sensor.
• inspect throttle body,throttle body valve and clean throttle body.

When we inspected the throttle position sensor, firstly discoonect the sensor, insert the feeler gauge   between the throttle stop screw and stop lever and ohm meter measure the resistance between each terminal.



multimeter:positive:-voltage in  ,                         negative:- fully throttle

TB fully open = 0V

TB closed =infinity

Now multimeter 

positive or red lead=Voltage in.        black lead or negative = on idle position 

TB fully closed =0V

TB open =infinity

THROTTLE BODY CLEANING:

Throttle body gets dirty from engine gas recirculation

(EGR), there is a small hose that spends post combustion gases into the intake.The post combustion gas dirties the throttle body and rest of the intake manifold,so when we clean throttle body oil  and dirt then it promotes engine effeciency.

TYPES OF AIR MASS SENSOR:

• L jetronic type air flow sensor.
• LH jetronic hot wire type sensor .
• D jetronic manifold absolute pressure sensor.
• karman vortex air flow sensor.