WS8 primary & secondary ignition patterns

toyota soarer 1994

Primary Voltage Patterns::
The primary pattern shows us how long it is grounded for, how much voltage is used to cross the gap (burn voltage) and how long it takes to cross (burn time) This is good to help with diagnosis because it shows how strong the burn voltage is and the time it takes to cross. (a good way is string theory) higher burn voltage short burn time, low burn voltage long burn time.


Secondary Voltage Patterns::
The graph shows us a similar pattern as the primary jus the firing voltage isnt as high but the burn time is the same. In the secondary pattern it shows At snap acceleration you notice straight away the burn voltage goes down and it has a longer burn time. This is as expected

NOTE: The primary curcuit colapses on it self inducing a voltage in the secondary of similar voltage. same pattern.

WS7 exhaust gas analysis

mazda 323 wagon 2000


Engine idling: cold- CO= 5.8 HC= 521 CO2= 11.52 O2= .28
This is a rich mixture causing high CO there is too much fuel and some is unburnt causing high HC CO2 level is good for emissions but not the car and O2 levels are good indicating no oxygen in the exhaust.

Engine idling: warm- CO= 6.970 HC= 493 CO2= 10.78 O2= .19
The CO reading indicates low oxygen because the O2 level is low also the HC are low indicating fuel is getting burnt. The CO2 reading is good but bad 4 global warming.

Engine warm 2500rpm: CO= .4 HC= 123 CO2= 14.6 O2= .47
These are good readings. similar to idle so it indicates that even reving it the car still functions okay under load.

Idle lean mixture: CO= .07 HC= 230 CO2= 11.88 O2= 4.9
The CO reading tells us that its a lean mix because it matches up with the O2 indicating there is heaps of oxygen and a little bit high HC means some unburnt fuel but thats caused by too much oxygen and the flame cant get across.

Blipping idle: CO= 3.349 HC= 1188 CO2= 9.09 O2= 9.34
These readings are no good. The CO indicates too much fuel which should lead to a low oxygen reading but it doesnt indicating we have an air leak somewhere. Heaps of HC meaning fuel isnt getting burnt an the low CO2 is related to heapz of CO and O2 not joining together.

Disconnected 1 spark plug: CO= .157 HC= 2672 CO2= 7.28 O2= 11.03
The O2 and CO relate meaning this should be a lean mix but the HC levels are so high which means there is unburnt fuel. This is caused by the 1 spark plug not firing (weak spark) leaving unburnt fuel behind.

Disconnected injector harness: CO= .068 HC= 188 CO2= 6.94 O2= 11.72
With the 1 injector not functioning the CO show that there is not enough fuel (lean) the HC shows theres a lil unburnt fuel which maybe caused by all the extra oxygen

under load: CO= .550 HC= 195 CO2= 14.02 O2= 1.58
CO showz the mixture is a lil lean but the HC also tells us that most of the fuel is getting burnt and the O2 readings are good meaning theres no air leaks or extra air and the CO2 are good showing good emissions but bad for the economy

WS6 O2sensor on vehicle

Toyota soarer 1994

On the vehicle I tested the oxygen sensor was located on the exhaust manifold. The oxygen sensor has one black wire which is a signal wire. The oxygen sensor is a zirconia switching sensor. I back probed the Oxygen sensor and attached an oscilloscope and got a signal. When revving the vehicle at 2500rpm the signal voltage reached 1volt and the lowest was 0.03volts. It has 9 cross counts. Its cycling normally.

WS5 scan tool diagnostics

mazda capella wagon:
Trouble codes found were 100 & 110 MAF & IAT respectively. These components wern't working properly. Using the scan tool the codes that changed were IAT 19.85degrees & MAF 0volts. Using the scan tool information I did a visual inspection and found air flow cold box meter sensor not properly pluged in and MAF sensor plug was also not plugged in properly. To repair the fault I plugged both connector bak in and now working fine. (good readings).
Recheck Data:
IAT 25.46degrees & MAF 1.87volts
Clear codes: removed scan tool for a couple minutes then plugged it back up and searched for codes. No fault codes found.

The importance of live data is that you can get information about the can then and there when its operating. For example you might get an O2 reading of 0volts and you might thick thats ok but when you check live data itl stay O2 sensor open loop and the voltage should be .45v.

The need for parameters when checking live data is that all signals come in and are calculated then an outcome is made, if one signal was faulty it could be affecting another components so we have parameters so we can monitor an idividual component.

A scan tool can aid you when fault finding because its current data and its telling you exactly whats happening and the fault codes it gives is a good indication on what and where the fault might be. (always start from the battery)

WS4 fuel pressure & flow

nissian primera 1992

There are no leaks. With the key on engine off the fuel pressure is 264kpa. On idle for a couple of minutes the fuel pressure is 260kpa. With the engine idling and then the fuel line is clamp the fuel pressure rises to 490kpa. When the vacuum line is disconnected and plugged on idle the fuel pressure rises to 310kpa. The rest fuel pressure was recorded at 250kpa after the engine is truned off and fuel pressure was watched for 5 minutes. The flow of fuel was 2.2l a minute.
After test equipment ws taken off and fuel lines hooked back up properly I check for leaks before it was turned on and after engine was running.
It is important to know a vehicle fuel pressure/flow to ensure that fuel is reaching the injectors and tat the right pressure so the car won't be running rich/lean.To much pressure could cause a hose to burst and to little could cause low combustion. Faulty fuel pressure regualtor could cause to much fuel pressure in the fuel rail and cause the car to use to much fuel and it won't be economical.

WS3B dual trace patterns

toyota 4A-FEMAP against Injectors:
As the MAP voltage increases the dwell time for injectors increase also. Therefore the injector increases more fuel due to more air entering the intake manifold. If the MAP voltage doesn't increase and the injectors increased in frequency the engine will run rich use heaps of fuel and poor emissions. (poor emissions is bad for the economy)

RPM against Injectors:
As the cam speed increases the dwell time will increase and the injectors will increase in frequency. If the cam speed increased the engine load will increase also and if the injectors stayed at the same frequency (1ms) you would get a poor combustion (weak) and it may even be early combustion and result in poor performance and eventually damage the engine.

Oxygen sensor against Injectors:
The oxygen sensor fluctuates at idle. As the engine RPM increases the fuel increases in the injectors. As more fuel enters the combustion chamber a rich mixture is burnt and a hi number of oxygen partical are left to flow past the O2 sensor. The O2 sensor can affect the injectors by, if the O2 sensor was reading hi oxygen levels the ECU will tell the injectors to lean off the mix therefore the injectors wont be working in relationship properly with the RPM sensor.
With a high voltage at the O2 sensor the engine is running rich.

Ignition primary against Injectors:
On idle the relationship between the two are the frequency that they are operating at stay the same and as the engine revs up both frequencys increases equally. If the ignition primary was out it would affect the injector by not igniting the air fuel mix properly or on time.

WS3A

Map (Analog) 2v 1sec
As the voltage increases the vacuum decreases. so at idle voltage is 2volts and increases from there as engine rpm increases. If there was a fault in this component or circuit it could effect the engine load. For example if there was high resistance (corrosion) in the earth wire itl effect the output voltage because voltage would be used to push through the corrosion to get to earth.

ECT eng cold .720v eng hot .538v
note: slowly decrease voltage as engine warms up. An ECT is a NTC thermistor. As the engine haeats up the signal voltage drops. If there is a fault with this component it could make the vehicle run rich if the signal voltage is high and the engine is hot. This faulty reading is not good for the car. A faulty reading can be caused by a faulty component. you can also get a faulty reading if you have a bad earth.


IAT 2v 10ms
Hot = 1.495v Cold= .5v
This records the air temp as it passes through the intake manifold. low voltage reading is when the air temp is cold. A high voltage is hot air passing through the the intake manifold. If there is a fault with the IAT like a bad earth you could result in in no signal voltage or high signal voltage if the IAT was faulty but stil had continuity.

TPS Closed throttle 5v Open throttle .5v
In the photo for TPS the low voltage reading of around .5v is the throttle closed on idle. As the voltage readings get high this shows us that the throttle is getting more and more open until it reaches W.O.T. If there is a fault with this component or circuit it can result in the vehicle not responding to the drivers intent. Bad resistance in this circuit will cause incorrect signal voltage. eg.. Vs x (R1+ R2) / R2 = Vout (normal equation) If there is extra resistance the equation would be Vs x (R1 + R2 + R3) / (R2 + R3)= Vout which would be different.

MAF digital
This component reads how much air is coming through to the intake manifold. If there is a fault with this component it can effect the engine load. For example if the variable resistor inside the MAF sensor is faulty the incorrect signal will be given or maybe no signal if it doesn't have continuity. For example if the MAF sensor was half open and sending a signal of .6v instead of 1v that .6v signal might tell the ECU to put less fuel in when infact it should be injecting more fuel.