Primary and secondary ignition patterns

I had to use a lab scope to get the primary ignition patern with the engine on idleing.I did these following tests on the 4A-FE engine.My task was to record the average firing voltage,the avarege burn voltage,average burn time and the average dwell time.I had to do this for each cylinder.

                              cyl1         cyl2          cyl3        cyl 4
firing voltage          248v        248v        248v       248v
burn voltage          55.6v       55.6v       55.6v      55.6v
burn time              1.48ms     1.48ms     1.48ms   1.48ms
dwell time             6.2ms       6.2ms       6.2ms     6.4ms

all these voltage reading are normal because they are all the same or when not the same they are very close together.This shows a good steady primary ignition voltage.

In this oscilloscope patern it shows the charge and discharged pattern of the coil.As seen in this pattern it drops shows the dwell the it rises by alot,this shows the burn time.The burn and dwell time is both measured in ms.the voltage division of this pattern was 5v and time was 1s.

Using stacked display is an advantage because it makes the pattern more accurate can see the voltage the voltage drop and rise more acuratly.
Next task was to view secondary ignition patern.I was asked to record the firing voltage and the burn time for each cylinder.The first one I had to do was under snap accelaration.

                                cyl1            cyl2                cyl3            cyl4
firing voltage            5.4kv          6.2kv              5.9kv         6.2kv
burn time                 1.1ms          1.8ms             0.65ms       0.71ms
snap acceleration     9.8kv           8.4kv             9.8kv          9.0kv

In this result it shows that the secondary is not as consistant as the primary but not bad either.Also shown is that it does not hav the dwell time.

The picture above is the pattern of the snap acceleration secondary ignition.The middle part were it goes up is the part were we reved the engine.This is were the firing voltage is calculated.This picture is of cylinder1.This is similar to the primary but the fact that secondary does not read dwell time makes them different

Next on was with a spark tester.Do this by ataching a spark tester to sparkplug wire

                           Cyl1           cyl2           cyl3        cyl4
 firing voltage       13.9kv        6.4kv        6.4kv      6kv
 burn time            0.7ms          1.41ms     1.12ms    1.4ms

In this results it shows that the voltage goes verry high on cyl 1 but the drops and stays steady and at this time the burn time is lower.This is because the spark tester was on cyl 1

voltage division in this one was 4kv and time was 8.7ms.In this picture it shows that it has one spike.this is where it sparked and where the voltage was higer and the time was lower.

exhaust gas analysis

This was done on a 1992 nissan primera.To do these test I had to use a exhaust analyser.Before I could use it I had to warm it up and calibrate it.When this process was done I put the analyser probed in the tailpipe.First I ha to know what everything means:CO2=carbon dioxide.These readings indicate that the catilatic converter is working.CO=carbon monoxide.These readings indicat catalatic converter is not working and if car is rich, HC=hydro-carbon.this shows about the misfire in the engine.O2=oxygen.this shows if car is rirch or lean.

The first test I had to do was start the car and let it idle cold and record the readings.It usaly takes about 30seconds for a acuarute reading to show.I got readings of:
CO:49%  HC:340ppm  CO2:12%  O2:0.6%
The engine getting warmer but the catalytic converter stil cold that is the reason for the CO reading being higher than normal.The HC is also high this indicates a high number of missfire.this is also because car i still cold.

The next reading i had to take was when the car is warmed up.
CO:6% HC:171ppm CO2:12.8% :O2:0.08%
This result indicates that the catalytic converter is not working efficiently.The hc number has come down alot because the car is at a good tempreature and steady went into closed loop so idles better.

Next reading was at 2500 rpm
C0:39%  HC:245ppm  CO2:12.8%  O2:0.16%
The HC number has gone up again because we increased the revs so the misfire count went up because it is at higher rpm more strain on engine.CO is still high shows the catalytivc converter is not working properly.

Next task was to make the car run rich and record reading.I did this by spraying a little carberator cleaner into the intake.
C0:7.7%  HC:1800ppm  CO2:14% O2:-O.O2%
The CO has still not realy improved.The hc in this one is verry high which sows a verry high amount of misfire.The O2 is verry low.this show that the car is running rich.

Next I had to make the car run lean.I did this by removing a vacuum hose.
CO:0.3%  HC:1400ppm  CO2:7.8%  O2:9.8%
In this one the CO is good.The HC is still very high because it is running lean the missfire number is high.The O2 is realy high.This shows that the car is running lean.

I had to accelerate for a short time and record readings when CO is reading highest.
CO:4.2%  HC:240ppm  CO2:13%  O2:0.15%
The CO at its highest reading is not verry high.This shows that the cat is working.the missfire number pretty high because rpm increased.The O2 reading is good car not running to lean or rich.

Next I had to disconnect a spark plug and ground it.
CO:15.2  HC:1900  CO2:13.7  O2:0.9
In this task the missfire number was verry high because it is only running on 3 cylinders.The CO is getting higher this indicates the catalytic converter is trying to work.

I had to disconect one injector.
CO:1.8  HC:282  CO2: 10.3  O2:5.3
Cat converter working pretty good in this test.O2 reading hig indicates that the engine is running lean because with the one injector disconected engine is not getting enough fuel

Made other changes do see diference.The changes i made was I turned the aircon on.
CO:3  HC:240  CO2:13.1  O2 0.14
Only thing that quite hig in this test was the HC but not to high.

If I did all these test on a vehicle without a catalytic converter the readings for CO and O2 will be higer because it will run lean.lambda O2 sensors has 4-5 wire because extra wires are used for signal wires.

This is a picture of what it looks like to get the reading on the analyser.

oxygen sensor on car

I did the following tests on the 1zz engine.On this engine this sensor was located on the exhaust manifold just when it goes into one pipe.This sensor has 4 wires:
colour                                 use
white                                  signal
white                                  O2 sensor
white                                  ground
black                                 power heater

The sensor I was working with was a zirconia switching sensor.I had to hoock up a oscilloscope to the sensor to get a patern.I did this by back-probeing the signal wire and putting my oscilloscope to it.My first task was to get a pattern at 2500rpm.With this pattern I found that the higher the voltage gets the richer it is.

The voltage goes as high as 0.715v and it goes as low as 0.1v.The average voltage was 0.6v,the oscilloscope had a function to calculate this.This sensor had 3 cross count.One cross count is when it goes from low to high or high to low.

My next task was to get a pattern of the oxygen signal at idle in closed loop.Closed loop is when car is warm and the ECU uses actual information to adjust sensor and not a set map like open loop.

In this one the voltage only went up to 0.2v and went to as low as 0.1v again.0.15 was my average voltage and again it had 3 cross counts.

In the next task I had to make my oxygen sensor go rich and get the pattern.I did this by giving it a quick accelaration.

This gave out a higher voltage of over 0.85v.If this did not give a high voltage the voltage will be changed and will not give a good wave form.

Next thing I had to do was make the oxygen sensor go lean.I did this by running the rpm to 3000 then sudenly dropping the throttle.

The voltage dropped from 0.8v to 0.1v.This shows us the lower the voltage the leaner the car is running.If the voltage is not high the waveform will be bad and wont go down as low as it should.

Next thing I did was measuring the response time I did this by sudenly acceleratin to see how quickly the sensor went from lean to rich.

The voltage went from 0.1v all the way up to 0.8v the bottom is at idleing the goin up is at accelerating and the top is when it is rich.It took the sensor 100ms to go from rich to lean


The zircronia sensor is based on a solid-state elctrochemical fuel cell called the nernst cell.On this system when the voltage is 0.2v this indicates a lean mixture and at 0.8v it indicates a rich mixture.It is most sensitive near stiochmetric point and less sensitive when rich or lean.

this is a good picure of http://www.wikipedia.org/ to show how the sensor works.

scan tool diagnostics

We did this on the 1zz engines.We were given a scan tool.

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first I had to know what the folowing means

Type of information(PID=Parameter Identification)	Letters to describe it	Value of data	Units for data
Engine Load(how much air comes in)	AFM(MAF)	2.58	Gm/s
Engine RPM	Engine speed	700	RPM
Throttle angle	Throttle position	11	%
Engine coolant temperature	Coolant temperature	71	C
Intake air temperature	Intake air temperature	22	C
Fuel Injection opening pulse	Injector pulse width	2.7	ms
Transmission select position	shift	4
Vehicle speed	0	0	Km/h
Oxygen sensor(s)	O2 sensor B1 S1	0.89	V
Fuel Trim	Short fuel trim#1	-20.3	%
Idle control	IAC duty ratio	37.5	%
Power steering condition	PS	off
Air Conditioning condition	A/C cut signal	on
Exhaust Gas Recirculation(EGR)	-	-	-
Fuel Evap or Purge condition	EVAP VCV	OFF	-
Malfunction Indicator Light	Warning light/MIL	on	on
I got this information from http://ttec4826-vlad.blogspot.com/2011/05/scan-tool-diagnosatics.html

I plug the scantool in to the diagnostic plug the I got the lecturer to create a fault.He did this and after selecting the vehicle and engine on the scantool the fault code came up.The code number was po120 I looked it up and found that it was the tps.The lecturer switched this of.By doing this he had caused a circuit malfunction.After this I had to find out what parameter identification of system voltage(pid)has changed. the type of informayion is throttle position letters to describe this is tps value of data is 0 units for data is % I did this with ignition on.I did a visual inspection to find the fault.To do this I checked for corotion,I checked plugs to make sure they are in properly.I checked all the wires and chech yhe voltage.I found that there was a circuit malfunction and when i could not repair it I got lecturer to turn back on.On the tps the yellow wire is the 5v supply the brown is the reference and the green is the signal wire.To clear the codes I said clear codes on scantoolI turned the ignition of. to recheck the codes I turned ignition on again and no codes came up.Live data is important because it shows faults and changes in the system and what is happening with the faults in the system.parameters is needed when checking live data because it shows changes and what is hapening in the system.A scan tool can aid you when fault finding because it is acurate and tels you what is wrong to be able to fix the car faster.

Dual trace oscilloscope

Doing the dual pattern works the same as doing the normal one but you just get two paterns.I still used the same oscilloscope but but went to menu and turned patern b on this makes it posible to see two patterns.hooking it up was not hard.I used one earth that went in the bat- terminal on the 1zz engine and then I had two red wires in two diferent terminals of the osciliscope then I put them in the terminals of the sensors patern that i wanted.When i got goo paterns I pased them and got the result.This can also be done with two oscilloscopes if needed.

The first pattern I got was map against injectors.The voltage for the map was 1v and voltage for injectors was 20v.For this one I used two oscilliscopes.The reason for this was because the map is alot slower than the injectors so I couldnt realy get a good reading for them together.So I used two earhts and started them same time and paused them at the same time aswell to get a good afective pattern

The left side is the injector and on the right hand side is the map.on injectors bottom line is burntime and goin up is charging and on the map as it goes up its getting more air.The two components relate to eachother because.When the map sensor goes up it means it is getting more air.This means the injector will spray more fuel because the ECU can see there is more air so there has to be more fuel.There is also more frequency at the injector when there is more air.the higher the map signal is the bigger the burntime of the injector would be because when it goes higher it gets more air so it needs more fuel.The components affect eachoter because if the map is faulty the air reading might be wrong so it wont spray right amount of fuel and it would make the car run badly.

The next pattern I did was for rpm crank vs injector.For this one I used one iscilloscope because it was all i needed.The voltage for the rpm crank was 10v and the voltage for the injector was 50v.When I first did this it did not work then I realized the crank sensor was not connected so I moved to another engine.

The bottom pattern is the rpm and the top patern is the injector.I had the time on 2ms.in the injectors were it goes doen between that and before it goes up again is burntime.with the rpm top is peak point.If I ad throttle the gaps between waves of rpm wil opn more.These components relate to eachother because as soon as the crank meets the o point the injector switches on.The slower the time which was 2ms in this time the bigger the burntime of the injector.This means that the components can affect eachother in a big way because if the crank sensor is faulty the injectors wont turn on when it should and cause the car to run badly.

The next pattern was for oxygen sensor against injectors.I did this one on a 4a-fe engine.

I had the oxygen sensor voltage on two volts and the injector voltage on 10v and the time on 5ms.the injector stil same. the oxygen sensor does not do much because the o2 sensor not as fast as injecor.These components relate to eachother because the oxygen sensor measures the gases and sends to ecu and makes injectors spray more or less.If there is a faulty O2 sensor the injectors might spray too much or too little fuel.this would cause the car to run lean or rich and could cause it to use more fuel.

The next pattern I did was for ignition primari against injectors.

I had the voltage of the injectors on 20v and the ignition on 5v with the time on 5ms.In this pattern the two wave forms are directly above eachother like the burntime of the injector is even with the ignitions time.when we rev the car the ignition goes up aswell as the injector pattern.these relate to each other because when ignition goes up injector sprays.This means if the ignition faulty the burntime of the injector will be wrong and the car will run badly might also run rich and use more fuel.

The last patern I did was ignition primary voltage against ignition primary current

The current rises as the primary circuit is completed as it show in this pattern the top one is the current and the bottom is the voltage of the primary ignition.I used a ohmmeter that i hoocked up with the oscilloscope to get the current pattern.

oscilloscope patterns

To get a oscilliscope patern I toock an osciloscopeand on the side of the engine was all the sensor terminal to make it easier to measure.I took the red terminal of the oscilloscope and put it into sensor I want to get the patern for and the black terminal in the bat- terminal and start the engine.then I change the voltage and time to get a better patern I did this throughout all my oscilloscope patterns.

The first oscilloscope pattern i did was with ECT.the voltage was 4.5-5v

With this one i put the time on 5seconds and the voltage on 2v for a good pattern.At cold temp the thermistor has a higher resistance.This would cause a high input signal at the ecu as the engine warms up the resistance gets lower and the voltage can change from around 4.5-5v.There are some electrical faults that can make this sensor operate incorrectly like,if it has a bad earth,could have a faulty thermistor,dirty plug or a lose connection.The reason these things will make the sensor malfunction is.If we had a high resistance of 1kohm int the earth it would cause a high voltage output to the ecu.this will cause the car to run rich and use more fuel.If this would happen the pattern would have gone up faster than it is going up at the moment.

second pattern was map sensors pattern.The voltage range was from 0.5-3.5v

Doing this pattern i had the time on one second and the voltage on 2v for a acurate pattern.The bottom of the pattern shows idling.The top of first wave shows quick acceleration.The top of second wave shows cruising when accelerating the voltage goes up to about 3.5v under snap acceleration.when just on idle the voltage is about 0.5v this increases when more throttle is applied.There are some electrical faults that could cause this sensor to work incorrectly like,if the map plug is not in properly,when plug gets dirty,if there is not a 5v input or could also be a bad earth.This could cause a malfunction because if not getting a 5v input because of high resistance the ECU will think the engine is still on idle  and wont open the injectors enough so it will be running lean and have a lack of power.If there was a pattern of this it would show that the wave wont be very good. this could make the car have a lack of power.

The next pattern I did was with a tps with a voltage range of 0.5-4.5v

On this one I again had to have the time on 1second and the voltage on 2v.The top of the wave is wide open throttle and bottom line show idle.This pattern sows us when increaseing throttle the voltage increases.at the bottom where it a straight line the voltage would be about 0.5v and the top where it wide open throttle would be about 4.5v and line going up would be between that but increasing as throttle gets applied.This sensor could have electrical faults like bad earth,lose connection or plug might not be in properly.If these things occur the tps wont work or wont operate properly and the ecu wont get the right signal.If this would happen the patern waveform would have gap in it.this could cause the car to have a flatspot when driveing not just on acceleration but also on deaccelaration and if the fault realy bad could even cause car to not drive at all.

The next pattern was of a IAT sensor.

Doing this one I had to put the time one one second and the voltage on 2v to get a good acurate patern.At the highest point in this patern it is cold and at the lower point it is hot.In this pattern the higher the voltage the more air it is getting through the system.A bad coonection or dirty plug will cause this unit to operate incorectly.if this sensor would be faulty we will get a unconsistant patern.This will cause the car to run badly and jerk as the throttle is applied.

The next patern I did was rpm cam.

In this one I set the voltage to 2v again but the ime was alot different at 50ms the reason for this is because it is a patern that is usaly alot faster.In this pattern the waves all look similar but when adding more throttle the middle part of the wave gets bigger.This is the burn time.When just on idlle all the wave should look quite similar.A lose connection faulty magnet will cause this sensor to operate incorrectly.If it has a fault magnet the sensore wont me able to ground properly and will cause it to send the wrong voltage.This would make the pattern unstable and unconsistant This will make the car have a posible flat spot and could also have a lack of power.

My next pattern was of rpm crank

On this pattern I made voltage 5v and the time 2ms for a acurate pattern.This is a nice consistant pattern all of the waves about same when rev the car all waves change together.The top of the waves is the peak point on acceleration.bad earth could cause this unit to operate badly and give a bad pattern that is unconsistant.This will cause a bad drive with possible flatspots.

The next pattern was of a oxygen sensor.

For this one I had the voltage at 0.5v and the time on 2seconds.As this sensor heats up the voltage gets highe therefore the pattern gets higher all the way through.the funny looking bit at the start is quick accelaration.

The next pattern was of the injectors.

I had this one on 10v and 2ms for a good pattern.The bottom line shows the burn time then the line going up to top is charge time right at the top is the peak point and then coming down again it gets discharged.

input sensors and actuators on car

The tests I did for this were done on a 4a-Fe engine commonly used in a 1992 Toyota corolla.The first test I did was to measure the voltage to the fuel injector,I did this by back probing the wire to the fuel injector with a pin.I got a result of 14v which is a good result.It is important to check the voltage of the fuel injectors because if the voltage is to low the injectors wont operate properly which will cause the car to run badly.If the voltage at the injectors are lower than the battery voltage the injectors wont open properly and wont be fast enough.This could be cause by bad connection going to the supply.I was asked to draw a circuit of the fuel injector.

The picture above is a picture of the circuit I drew with all the components named.

The next sensor I did was tps (throttle position sensor).The tps has a 5v reference in this case it was the yellow wire.The reason for a 5v reference is because it is the power to the sensor this is to provide a good signal to the tps.Sometimes the reference voltage could be wrong.This could be caused by a high resistance in the feed because it is a straight feed.The next test I did was testing the ground at tps sensor.I used a pin to back-probe the sensors earth.I used a multimeter I put the red terminal on the pin and the black terminal on the engine to ground it I put my multimeter on dc volts and got a result of 0.002v.This result shows me that there is a good earth.This is important because if there is a bad earth the car wont run properly.A broken earth wire can cause the ECU to have a bad earth.I located a tps input and back-probed the wire measured voltage with a multimeter with the ignition on and got a result of 0.384v.I opened the throttle half way and got a reading of 2.23v then i opened the throttle all the way and got a reading of 3.789v.I did a test by slowly opening the throttle fully from closed and watched the reading increase slowly this means it is good result.A tps sensor works by using a input voltage and a variable resistor around a shaft to send a output voltage from .5-4.5v depending on relationship between shaft and variable resistor.The ECU should usually get a voltage of 0.5v at idle from the sensor to 4.5v at wide open throttle.There are some things that can prevent the tps from sending the correct voltage like faulty earth,faulty input and also faulty tps.I was asked to draw a circuit diagram

The picture above is the circuit I had to draw.The reason there is a output needed for the ECU to properly run the engine is because the ECU needs to adjust all the sensor to what the driver is doing for example:when the driver is driving a wide open throttle the car needs more fuel therefore the injectors needs to spray more fuel.

The next sensor I tested was the engine coolant temperature sensor.

I found the ect on this engine then I back-probed the supply wire to the ect.I turned the ignition on and used my multimeter to measure the voltage at this point and I got a result of 3.58v.The engine is at normal temprutare at this point.I started the engine and measured voltage again and I got a result of 1.1v.This result shows the sensor is good because the voltage decrease whhen the engine tempreture increases.The ect works with a set resistance in the ecu that make the use able to adjust sensor to the engine.The ect voltage can also affect the fuel injection because a higher output from the ect at cold tempreature gives a higher voltage to the ecu causing it to ground injectors for longer.A faulty thermister or a faulty earth will give the ecu the wrong voltage which could cause the car to run badly.I back-probed the black wire which is earth and measured voltage with multimeter and got a result of 0.1mv this result shows sensor has a good earth.A lose connection could cause a bad earth.

The picture above is a picture of a circuit diagram I got this of google images.

The next sensor I did was the rpm sensor.
To test this sensor I back-probed a rpm signal wire with a pin and put my multimeter on ac volts.I strarted the engine and measured the voltage and got a reading of 90mv.I increased the rpm to about 2500 and got a reading of 197mv.I switch the multimeter to dc volts and at idle I got a reading of 1.2v.I then again increased the rpm to 2500 and got a reading of 16mv.I then switched the meter to Hz and got a reading of 5kHz after increasing rpm again I got a reading of 7.5kHz.These result shows that Ac voltage was the best way to see if the rpm sensor is working.The 4a-fe engine I was using had a hall effect type rpm sensor.This type of sensor works with a magnet and a plate plate pases through the magnet then it grounds and sends a voltage out the sensor wire.It is good to use diferent functions of the meter to get acurate results it gives us an idea of what the patern would look like because we know the size and power amount of it.


The next sensor i did was map or maf sensor.
I backbrobed the map sensor and measured the voltage with the ignition on and got a result of 1.8v.I started the engine and let it idle measured it and got a reading of 0.48v.Then i gave it a quick short accelaration and got a result of 1.8v.The map sensor works with presure and measures it and sends it to ECU with the signal wire and the ECU adjust the engine to that result by using other sensors.the readings i got was correct because it went up when short acceleration because there is more preasure.bad conection or pipe not on could give ecu bad reading

This is a circuit diagram of a map sensor.

The next sensor I tested was the IAT(intake air temp)
I had to back-probe the sensor and turn the ignition on and measured voltage and got a result of 3.3v.This reading is 0.2v less than that of the ect.This show that the iat is hotter than the ect.The IAT works by measuring the temp goin through the intake and sending it to the ecu.The IAT voltage effects the ecu for fuel injection in the same way as the ect if it is wrong the injotor time would be wrong.The sensor signal sends out a higher signal if the tem rises.A bad connection or bad earth can cause the incorect signal for the ECU

Next sensor was camshaft position sensor
I had to measure the cmp in 4different settings to find the best one.
DCvolts:19.5mv
ACvolts 1.2v
hertz:0.09kz
%duty cycly:14.1%
duty cycle best way to measure this.

fuel presure and flow

This test was done on a 4a-fe.Before these test can be caried out it is inportant to know where the fire extinguishers are i only found one wich was located on the lefthandside of the door when you are entering the room.The presure specifications on this engine was 38-44psi.When i caried out these test i used psi for all my  pressure readings.The first test i did was to measure the fuel presure with engine at idling and got a result of 36 psi the engine had a gauge for this so just had to read the gauge to get a result.Next test was to use a speacial clamp given to me to clamp the fuel return for a short while and get the reading.I got a result of 89psi.My next test was to disconect the wacuum line going to fuel regulator and record reading.I got a result of 45psi.I had to turn the engine of and watch the reading after 5 minutes I got a result of 40psi.It is inportant to know the vehicles fuel presure because it can give you a indication of what is wrong with your car and if your car is smoking it mitght be because it is running rich then you will be able to check this if you find owt your fuel preasure.When a car has got low fuel preasure it could have a leak somewhere in the fuel system that is causing this.When the car has got high fuel preasure it could be caused by a block in the fuel lines and this could also cause it to leak because it is getting to much presure and could cause it to run rich.When the car has a faulty fuel regulator this could be caused be diferent things depending on what is wrong with the regulator.If the regulator is stuck open it wil have a low fuel preasure and have same symptons and when stuck closed it will have a high fuel preasure.When the car has low fuel flow it can run a bit lean and feel like there is a lack of power this could be caused by a dirty fuel filter or a faulty fuel regulator

Flash codes

This test was on car and the engine I used was a 4a-fe out of a 1992 toyota corolla.I was given a jumper wire with a fus to prevent blowing anything up.The tutor made some faults on my engine,I had to use the jumper wire in the diagnostic plug to try and find the fault.I used the manufacturers manual and found that I had to use my jumper wire between TE1 and E1 to get a code.The code apears on the dash as the engine light.If the engine light flashes 2times then stops and flashes 4times then the code is 24. In the manufacturers manual it has all the codes and what they mean.I was given 3 faults on my engine and found them.

code number                           system affected                        condition described
24                                           intake air temp                          effect air fuel ratio
31                                           vacuum sensor                         running real bad
41                                           tps                                           bad idle

After i found these faults i did a visual inspection on the engine at these sensors and found that all those sensors were unpluged so to repair these faults all I had to do was plug the plugs back in.To clear these codes you turn the ignition of and back on again.To recheck the codes i fixed the faults and reset the codes and it was clear.The faults I found can effect the performance of the car because with vacuum sensor wiil run rich and use more fuel and with the tps it will hav a flatspot and also with the iat but difrent more jerking type.after test are done just had to make sure are lights on dash are off

Backprobing on the bench

Before we where aloud to work oncar we had to fill out a booklet with simpel test in it to make sure we know how to backprobe without dameging the wires.The first test there was to do was to turn the multimeter on put it on ohms make sure leads not touching anythig and record the reading.The reading was OL this means open circuit.Next test was to put the meter on ohms again and touch the leads together and record the readings I got a reading of 0.4ohm.This result tells us there is a resistance of 0.4ohm in the multimeter.The next I had to do wasbackprobing wires.I was given a hard shell conector to do the test on.I used a needle and put it in gently on the one side of the wire and then on the fron of the plug and measured the resistance and got a result of 0.5ohm.I know i had a good conection because the resistor was less than one above the internal resistance.

this picture shown above I got of google but it is similar than what I have done in my testing

Distributor

The first test I had to do was measure the resistance in the distributer I was given the specifications for this distributer:
     name                           specifications                    actual           
g pickup coil                   185-275                             241.5ohms
ne pickup coil                 370-550                             492.7ohms

The first one I tested was the speed sensor(g picup coil)

I got the pins for this plug to find out which of the pins goes to the speed sensor then I wired it up and checked the resistance across it and like shown on the multymeter I got a result of 241.5Ohm.The second one i tested was the position sensor.

I already had to get the pin out for the plug to do the speed sensor and it is the same distributor so used same information and wired it up for the position sensor and measured the resistance and got a result of 492.7ohm wich is a lot higer than the speed sensor reading.this distributor is reuseable because both the result was wel within manufacturers specifications.


The second test i did was adjusting reluctor air gap on magnetic distributor.I used a feeler gauge to measure the air gap between pick up coil projection and the reluctor tip

The picture above shows the test being carried out.Thespcifications was given to me.

specifications                                                           actual                                     serviceable
g pickup coil        0.2-0.4mm                                  0.305mm                                yes
ne pickup coil      0.2-o.4mm                                  0.305mm                                yes

This ditributer is reusebale because it meats the specifification that was given to me.In this test you can see i took the feeler gauge and put it between the pickup coil and the reluctor tip.The pickup coil is the black box loocking object on this side and the reluctor tip is the tip sticking out of the top.I aded more sleaves of the gauge untill i had a good fit check what it was and this is how i got my result.

The third test that had to be done was to hook up the distributor to an osiliscope and record the patern

This is the patern I got on the osciliscope.I wired up the distributor to an osiliscope then i turned the distributor by hand and this is the patern that i got.

The next test I did was with a hall efect distributor.I wired up a hall efect distributor with a 5v supply then turned it by hand 45degrees at a time to see what hapens with the voltage

degrees turned                               voltage
0                                                   1.08v
45                                                 4.5v
90                                                 1.08v
135                                               4.5v
180                                               1.08v

these result shows it only realy has two voltage output there for if you pick up the ditributor 0degrees can be anywhere then u turn it voltage goes up turn it again voltage drops.

This is the wavform I got with the hall effect sensor.
The third tistributor I tested was a optical distributor.The distributor has three wires red for 12v supply black for earth and blue for signal out I did the same test as with the hall effect and got results of

position(degrees)                  voltage
0                                          5v
30                                        4.5v
60                                        5v
40                                        4.5v
120                                      5v

The results are the same as with the hall effect but with a lower voltage drop.Every time when it has a voltage drop with both the hall effect and the optical distributer it is when the engine fire when this is put into actual play in an engine.

oxygen sensor

We did not do test this sensor but the tutor did do a demonstration on it infront of the class.He used a vice-grip to hold the sensor and wired it up by having the negative of the volmeter on the case and the positive on the output wire.He used a propane torche to het up the sensor he did this for about 20 seconds and we got a reading of 0.8v he removed the tourch and we got a reading of 0.09v after that he heatedd it for two minutes voltage droped.After doing all these test we found that this sensor was a good and reusable because it met all the necesary specifications

This is a picture i got of google that show a good example of what the tutor showed us in class

knock sensor

To test this sensor I had to hoock it up to a oscilloscope and gently tap the end of the sensor and observe the waveform.It took me a long time to get the osciliscope set up perfectly because i was reading it to fast and when i changed it was to slow and cooldnt get a good reading.it gets a voltage reading even though it wasnt hoocked up to a supply.the reasone for this is beacuse it has crystals inside it caled peso crystals and when they move around and hit when you hit the sensor and it causes a voltage

This is what my wafe form loocked like after i taped the sensor against the desk.You can also see a good picture of the actual sensor in his hand.This patern also shows that this is a good knock sensor because a bad sonsor wont give a complete patern like this one because it wont have a voltage.A knock sensor Iis the sensor that makes you hear the pinging noise that your car makes when timing is wrong or runing the wrong octane fuel for your car.

thermister and thermo fan switch

To test the thermister I had to heat the water and check the temp with a thermometer and check for resistance.I did this and got results of

water temp              resistance
33°c                        1.36kohm
35°c                        1.33kohm
40°c                        1.14kohm
45°c                        0.96kohm
50°c                        0.78kohm
55°c                        0.68kohm
70°c                        0.407kohm
75°c                        0.390kohm

The results above shows that the higher the temp of the water the lower the resistance is in the thermister. the thermister i tested was a ntc type wich satnds for negative tempreture coefficient.This thermister is called this because the resistance decreases with increasing temperatures.Thermister is basicly just a resistor and its resistance changes with temperature.

THERMO FAN SWITCH
I put the switch in the water and set up the temp my task was to measure the resistance between the terminals at diferent temp to see wat happens with the resistance in the switch.

temperature                                       resistance
room temperature                              70.5 ohm
45°c                                                    0.8 ohm
50°c                                                    0.7ohm
55°c                                                    0.9ohm

This fan switch does not meet manufacturers specifications becaus acaurding to the specifications the fan is meant to switch at 80°c but the switch that i tested switche before 40°c i know this because when it switche the tem drops to under 1°c.The thermo fan switch should not be confused with a thermistor because it is not one.The switch has two resistors inside it,it switches from one resistor to the other when the fan switches on thats y the resistance is so much diferent from when it switches on and when it of.

vane type air flow meter

I wired up a airflow meter to find out what the diferent voltage outputs are with the diferent vane angle

vane angle        voltage out
0                        2.2v
20                     4.7v
40                     6.8v
60                     7.6v
80                     8.1v
100                   8.5v
120                   9.4v

The result shows that the more angle aplied to the air  flow meter the more voltag out.When i did some research on this airflowmeter to get the specification I used google and put in the partnumber(bp0513210)i found that this airflow meter came out of a mazda 323 it measure airflow with a spring loaded flap

This is an example of a vane type air flow meter