TTEC4843 - EFI Of Car

TTEC4843 - Fuels and Fuel Systems -  practical

15/9/2011 tuesday

start = 1.00pm finsh = 4.30pm

Cleaning Injectors

In todays task we got to learn how to check and clean electronic fuel injectors. first we had 4 injectors to check. and we had our mnufacturers specifications in relation. then we put our injectors in the machine. then we checked for injector

•  leake age and we had 0 drips per minute.
• injector flow rate 360 cc per minute flow rate at 2500 hz.

That shows us our injectors we tested were in good condition we had no leaks, the O rings are good, and they spray nicely . so they are servicable

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 airflow sensor condition by comparing the results with the manufacturers specification.

• First thing we did was tested E1 - FC closed had reading of infinity
• E1 - FC open .103 kohms

This shows that if the fuel pump relay is effected on pump operation with a high resistance across the two terminals. this wont give the right measuremnt and the amount of fuel.

Air Temperature sensor Test

In todays task we did testing on a air temeperature senor. and we checked our resistance using a multimeter ( ohms ) first thing we did was check the sensor resistance we did 3 testing.

• Intake air temp. 20'c ( 68'f)      Resistance (kW) 2 to 3 = 1.78 reading
• intake air temp 40 'c ( 104'f)    Resistance (kw) 0.9 to 1.3 = 1.24 reading
• intake air temp 60'c ( 140'f)     Resistance (kW) 0.4 to 0.7 = .07 reading.

this showed us that our air temepature sensor is good and it meet the specifications. but if it didnt meet it spec . replace the air flow meter if the resistance reading are not within specification.

MAP sensor

In todays task we learend how to test an MAP sensor and see if its also holds vacuum.

• first thing we did was get a vacuum pump and a multimeter volts Dc. and see for voltage drop.
• we applied our vacuum pump by putting it in the MAP sensor. and we did five tests  on it.
• First thing we did we applied 10 vacuum mmHg and we had reading of .89 volts
• 20 = 1.51 volts reading
• 30= 2.15 volts reading
• 40 = 2.88 volts reading
• 50 = 3.34 volts reading

That showed us that every time we apply pressure to our MAP sensor our volts start rising up and changing.


Coolant Temperature Sensor Test

In todays task we learend how to check a coolant temperature sensor. first thing we did we had two coolant temerature sensor.  then we added water in a steal bowl and placing a thermometer and gradually heat the water . we had measurements that we had to follow and by using a multimeter (ohms) to check for resistance.

 

Water temperature	Resistance
-20'c	14.6 - 17.8 w
20'c	2.21 2.69 w results= 1.34 ohms
80'c	290 - 35 Results  = 0.44 ohms

This results shows above showing that our resistance droped which we started at 20'c then heated the water too 80'c. that means we got a (N.T.C) negitave  Temperatur coolant. and our results didnt meet the spec . so that means the sensor should be replaced.

Air Flow /Mass Sensor Testing

We tested the hot wire type sensor. and we had a open circuit so we couldnt test it . It was faulty

Throttle position Sensor  (Linear Type)

In todays task we learend how to test a TPS sensor by using a multimeter ohms

 

Clearance between lever and stop screw mm (in.)	Between terminals	resistance (ohms)
0 (0)	vta - E2	200-800 -Results=505 ohms
0.35(0.014) Feeler gauge	Idl - E2	2,3000-or less -Results=70 ohms
0.59 (0.023 Feeler gauge	IDl -E2	infinity -Results=Infinity
Throttle valve fully open	VTa-E2	3,300-10,000 - Results=3300 ohsm
-	Vc -E2	3,000 - 7,000 - Reults=4200 ohms

 

This shows our TPS meet the spec. if the TPS resistance is not correct is by using a screw driver loosn the bolts and gradually turn the sensor clockwise until the ohmmeter deflects then  screw it back with the 2 screws.