TTEC4843 :- FUELS AND FUELS SYSTEM

Date:-19/9/2011

IDLE SPEED DEVICE:
In this task we tested the idle speed device.

• First thing was asked to check which type of cold or fast idle speed control does our vehicle use?- our was "stepper motor".
• And the base idle speed is adjusted here by ECU. 
• Here the cold / fast idle speed is control activated by "ECU".
• The correct procedure for checking this control is- ,firstly check the resistance winding test, then test duty cycle and frequency (spec 9-14v) and connect the bridging wire on terminal TE1 and E1 to check control.
• our result for the resistance in winding: used multimeter n used to find btw two pins.
  RSO-EO1=33 OHMS
  RSC-EO1=24 OHMS
• Then we used the digital meter to measure the duty cycle and frequency that operates the IACV- OUR RESULT WAS ... !DUTY:-Open 51% & close 49% 
  Frequency:- 244(open) & 244 (close) hz

Report: Our engine was in all good condition , the ECU adjust the base ideal speed where as idle speed control is determined by engine temperature and the time engine is cold means more air flow. Then we checked the continuity, we measured the resistance windings by keeping the black & red probe on RSO (open) & RSC (close)..which was 33 ohms and 24 ohms. Then had our duty test which was 51% & frequency came to be 244hz , that showed us how many times it turns on/off.

Checking Fuel Lines:

Firstly we checked the condition of fuel hoses, :- firstly had a visual check on the fuels lines on the vehicle, then checked for any cracks or perished rubber hoses, are the lines tight,check for any leaks ,check if its lose or bend.

RESULT:- PASS,.... OUR VISUAL CHECK ON FUEL HOSES IS ALL GOOD , THERE IS NO LEAKS AND EVERYTHING IS TIGHT & GOOD CONDITION.

CHECKING FUEL PUMP(fuel injection high pressure):

It is an electrical pump which can be mounted either inside or outside the fuel tank.

Here we learned how to work with the high pressure fuel. Firstly we use manual book to follow the procedure..as follow.

• we check the running pressure at idle.
• we also check the running pressure under full engine load.
• Then check the maximum output pressure of the fuel pump
• And in last check the residual line pressure.

SAFETY PRECAUTION TO BE OBSERVED: Check for the rsidual pressure when car is off, decrease the pressure by disconnecting the fuel relay,while the car is on.

MANUFACTURER'S SPECIFICATION: 

Ignition on: 265-305kpa

jumper disconnected: 206-255kpa

ignition off:147kpa

OUR TEST RESULT:

Pressure at idle:270kpa

WOT pressure:340kpa

Max Pressure:560kpa

Residual Pressure:255kpa

All, good the pressure were within specification.So, all good.

CHECKING FUEL PUMP FLOW:
After the pressure checks ,we can check the fuel flow through the system. Firstly after droping the residual line pressure, remove the pressure gauge from the fuel system. Then with the help of the manufacturer we'll check the fuel flow *after the pressure regulator for normal pump & *before the regulator for maximum pump flow.


Then ,it shows us the flow rate in minute for the pressure regulator for the fuel pump.

MANUFACTURER'S SPEC: 195-MAX FLOW & 135-NORMAL FLOW

OUR TEST RESULT:
                                                                              NORMAL
10SEC-540ML(.54L)                                        10SEC- .39L
60SEC-3240ML(3.24L)                                      60SEC- 2.34L
1HOUR-194400ML(194.4L)                               1HOUR- 140.4L

LOCATE AND IDENTIFY SELF TEST CODES AND ISOLATE CAUSE.

In this we learned how to identify and do self test code.
The vehicle we started with was Toyota 4AFE , flashing light on the dash board is the method used to display the diagnostic codes.

SPECIAL TOOLS AND EQUIPMENTS WE USED : jumper wire , scan tools to check the faulty codes and scope to check wave pattern.

*Firstly we bridge the wire from TE1 TO E1 terminals and then count the number of blinks of engine light on the car dash board.

The fault detected from us was 22,31,24
22- water temp.circuit (coolant sensor)
31-vacuum sensor circuit(MAP).
24-Intake air temp.sensor.

*THEN ,we rectified the faults , firstly we checked the connection on sensors.

• MAP sensor- were checked using vacuum pump and voltage regulator
• Coolant sensor temp.switch- checked by using heat gun water and thermometer.
• Air temp.sensor - heat with heat gun & check temp.with leaser sensor.

FINALLY:
The faults were solved with d help of the blinking light we recognized the above codes...and started finding the problem.in there , All the above codes were solved by reconnecting the circuits or wire, which were unplugged, And during in between the lights use to confuse us by blinking differently ,for this after every fault solved we should take the key off and start after little while.

SERVICE AN AIR CLEANER:
 It is really important that the air filter should be clean and working properly .It is not filtering the air entering  the engine dirt and particles as it will cause damage to the engine, and if itz blocked then it gonna affect the emission and fuel consumption.
Firstly we removed the air filter and and checked for damage or excessive dirt or any oil contamination to the filter element.
*all was good,it passed the inspection
*condition still all good and can run till the next service without any problem.

PCV VALVE:
we performed on the testing of pcv valve, first thing we did  was ,we clamp the rubber hose(using a brake hose clamp) going to the pcv valve does the idle change?YES(SO,PASSED)

*Then we checked for clicking sound which can be checked by listening,so as to knew that the plunger can move freely? yes

AS DURING CLAMPING THE RUBBER HOSE THERE WAS AN IDLE  SOUND CHANGE , WHICH SHOWS PCV IS IN GOOD CONDITION. SO, NO FAULTS AND ALSO THERE WAS CLICKING SOUND WHICH MEANT THE PLUNGER IS MOVING FREELY.
ALL GOOD.


VACUUM OPERATED EGR VALVE:
Today we tested vacuum operated EGR valve.


Record the EGR test result:

• Did the engine idle smoothly at normal operating temperature?-YES
• Did the idle speed change with vacuum applied to the EGR valve? -YES
• Did the valve show any signs of air leaks through the stem seal? -NO
• Is the EGR system working to specification? -YES

OUR RESULT:
No service require yet, all working good as manifold doesn't suck gases on idle and an crusing gases started being vacuum into NOX area in manifold.

The EGR is used to control/reduce NOX emission by introducing exhaust gas back into inlet ,there by reducing the combustion temperature.

ADJUSTMENTS AND EMISSIONS:
 In this we learned about adjustments and emission, firstly we tested a vehicle with carburetor and without a catalyic converter and then recorded the result.

• Firstly we bring the engine to operating temperature.
• Then we prepared the infra-red gas analyzer as required.
• Then calibrate the gas analyzer gauges.
• After which we set it to zero and adjust the span settings (analogue gauges).
• Fitted the sampler hose into the exhaust of the vehicle.
• In last we took the exhaust gas sample.

 And our result was:


ACTUAL BEFORE ADJUSTMENT                                   INDUSTRY STANDARD
H.C. - 159 ppm                                                                       H.C.  - 50 to 500 ppm
C.O. -0.528 %                                                                         C.O. - 0.5 to 1.5 %
CO2 - 14.24 %                                                                         CO2 - 13 TO 14.5 %
O2 - 0.18%                                                                               O2 - 0to 2.0 %


RESULT : YES, all good reading within specification.


EFI VEHICLE TEST:


ACTUAL                                                 INDUSTRY STANDARD

H.C. - 178 ppm                                           H.C.  - 50 to 500 ppm
C.O. -0.824 %                                           C.O. - 0.5 to 1.5 %
CO2 - 13.84 %                                          CO2 - 13 TO 14.5 %
O2 - 1.14%                                                  O2 - 0to 2.0 %


*THE RESULT WAS ALL GOOD.
The difference we noticed in two sets of reading as follow:

• HC it alwayz should be lower , as if its high then the specification it refer that the fuel is not buring properly.
• CO  is also same as HC , they may  too cause rich mix 
• if CO2 is high , it means engine burns efficiently , however if O2 is high , it means the mix is  too lean and its not good.

REMOVAL & REPLACEMENT OF DIESEL FUEL INJECTORS:

We learned how to check diesel injectors and inspect.

we firstly removed the diesel fuel injectors, then using harbridge test master machine we tested each injector.Then putting each injector one by one on the machine check for the spray pattern.And if there is any problems with them we set our machine to 18 psi, then pumped the injectors and we could not meet the specification as the spec fr ATM WAS 118 to 125 bt the result was all out. So need to change all four injector as they couldnt meet the specification n have not gud spray pattern evn thr was leakage.

BLEED AIR FROM A DIESEL INJECTION SYSTEM:-

HERE WE LEARN HOW TO BLEED THE AIR FROM DIESEL INJECTION SYSTEM.Remove the fuel pump filter to bleed from the hand , then loose the fuel line and disconnect it from the fuel distributor, then put the fuel filter back and start pumping the filter from this the fuel will start comiing out from fuel line , first it will not be soo flued because of air pressure bubles inside but once it get fluent, put the fuel line back .start the engine and checked., all good.

Decribe the location of the air bleed screw on d engine??

ANS- it was on the fuel pump top close to the fuel return.

TESTING ELECTRONIC SHUT OFF VALVE:-
 

We tested the electronic shut off valve with the ignition on, then we have to use the multimeter to test the voltage coming from ignition switch to the electronic shut off solenoid.

voltage- 12.4 v

Resistance of solenoid winding- 9.5 ohms

 OPERATION O SOLENOID:

Solenoid is not NA, but we checked the one which is attached on the engine diesel pump. So, when we connect the wire of solenoid then the clicking sound indicates the solenoid working properly And our result 12.4v shows that the solenoid is working as voltage is detected & the resistance confirms us the coil is working properly.

DIESEL INJECTOR PUMP TIMING:

HERE WE LEARNED HOW TO TIME A DIESEL INJECTOR PUMP.

DTI-Remove the cam belt and rotate the pulleys to TDC and reset them to there points , put the belt back and tight the pulleys back & tight the belt , taking care to have the timing makes aligner and  engine on TDC firing number one.
SPILL TIMING- done all good, jst have to remove the full injector lines , and adjust it.

Special tools- DTI gauge, socket tools , allen key /hen key tools.

TESTING GLOW PLUGS:

We tested the glow plugs.

                    glow plug1        glow plug2         glow plug 3         glow plug4

current draw         8amps                    8amps                    8amps                       8amps


colour of glow        turns red                  turns red               turns red                 turns red

plug tip. 

RESULT: Firstly we removed the 4 glow plugs and earth them to the ground to check weather they are working or not , we checked 4 of them all were pass as the top of them turns to be red.As they turn red that means there are working properly and there wont be any trouble.this shows us that the plugs are useable and cn be charged.