Back Probing

This is a practice to be able to get a reading from a back of a plug specially in the situation where we need this plug connected but also want to get a reading while its connected to its counter part .... We do this process so that we don't damage terminals, connectors and also wires.
To do this we use a sewing pin to gently insert it to the back of the plug so there is a contact with metal so we can obtain a reading.

1. Turn the multimeter on and put the setting to it would read Ohms (resistance)
O/L : is the result when the leads not in contact with each other , O/L stands for over load which confirms that we have an open circuit and the resistance between the leads are too high for our multimeter to show hence O/L.

2. Obtaining Ohms reading with leads connected.
0.5 Ohms which tells us the internal reasistance of the Ohms meter and the leads... we need to take this resistance out of any resistance we measure with this meter so we could have an accurate reading .

3. I used a plug which had one side of the pulg and the wire still attached so I back probed the plug and measured the resistance from the plug to the end of the wire which was 1.1 ohms
so 1.1 -0.5(internal resistance)= 0.6 ohms which is the correct resistance readings

I tired to back prob my distibutor so I could get a reading but the plastic around the wire was solid due to years of extereme heat .
I back probed Toyota soarer O2 sensor so I can get a reading after it was warmed up and working , real easy because it was single wire so 1 lead to the O2 sensor and the other to the -negative battery terminal (0.7 votls)

WS8

Firing voltage : the voltage (push) that is needed for the spark to jump the spark plug gap.

Burn voltage : the voltage need ed to maintain an arc between the spark plug electrodes so it can burn all of the fuel in the combustion chamber.

Burn time : the length of time which the arc is maintained between the spark plug electrodes

this is normally used to check the secondary circuit components eg. spark plugs , HT leads , secondary ignition coil, distributor cap , rotor and king lead .

Dwell time : the length of time which the primary circuit is grounded (turned on) before each cylinder firing so it can build strong enough magnetic field so then secondary winding can create a strong enough spark to jump the spark plug gap .

Primary Ignition Pattern : It is a very good way to check our primary ciruit and also to see firing voltage and burn time ... the higher the firing voltage the shorter the burn time this uses string theory so as the firing voltage decrease our burn time inceases .

Secondary Ignition Pattern : This pettern is a reflection of the primary ignition and has the same charactristic , its produced by the primary circuit collapsing on its self and inducing a voltage very similar to the primary pattern but the firing voltage is lower . After a snap acceleration we can see the firing voltage decreases and burn time increases which proves the string theory.

Toyota corolla FXGT 4AGE

All of these readings are normal ( checked against manufactorer spec)

We can see here as I am flicking thru all 4 cylinders that they are very similar and if there is an odd one then we know there is a problem with that spark plug , lead ... a very good way for diagnosis.

We can see in the above video dwell time increases as the engine RPM increases , this is so that it still can provide a strong enough spark due to the coil being earth out earlier before the cylinder reaching TDC in the compression stroke.

In the table below we can observe the string theory in action ... as the cylinder 4 has been grounded to the body the firing voltage decreases because it does not need as much voltage as in a sprark plug but this causes the burn time to increase

Again we can see in the table below that because the gap in the tester is smaller than the spark plug gap then firing voltage has decreased , the burn time has increased

WS7

CO:

Carbon monoxide is a indicator of rich air/fuel mixture and shows there is not enough oxygen in the combustion chamber. The lower the better because it is a very dangrous gas and lethal for humans because of it properties and also indicating not a efficent combustion due to too much fuel and not enough oxygen.

HC:

Hydro carbon levels show the amount of unburnt or partly burnt particals in the exhaust. misfire due excessive lean and also rich air/fuel ratio ,misfire can also be due to ignition problems.The lower the levels of HC the more efficent the fuel is being burnt in the combustion chamber . It is also a green house gas and related to global warming.

CO2:

Carbon dioxide is a good by product and indicates good combustion inside the engine and is produced when the fuel is oxidised , a good rule is the higher the CO2 level the more efficient the engine works .Even tho this is a a good gas for an engine it is also concidered a green house gas and related to so called ''Global warming''. Air/ fuel imbalances , misfires and mechanical problems in the engine will decrease the amount of CO2 produced because ideal combustion will produce high levels of CO2 and water vapor. A good way to measure combustion effiecency.

O2:

high levels of oxygen is a good indication of lean air/fuel mixture because O2 increases as the air/fuel mixture gets leaner , it also can indicate misfire but we have to look at HC to come up with this conclusion .

CO: 5.8 HC: 521 CO2: 11.53 O2: 0.28 Cold engine idling

CO is high which shows rich air/fuel mixture because the engine is cold , High HC again indicates not an efficient combustion and high levels of fuel not getting burnt completely. in comparison with the level of CO2 when the engine is warmed up this indicated not a very efficient combustion . O2 levels are low as the air/fuel mixture is rich .

CO: 7.1 HC: 506 CO2: 10.6 O2: 0.20 Warm engine idling

CO level still high wich indicates rich air/fuel mixture, HC is also high which tells us there is high number of fuel particals not being burnt due to rich air/fuel mixture and not enough oxygen being present to help burn all the fuel off. CO2 is also low which cofirms rich mixture and finally low O2 which can also tell us rich air/fuel ratio.

CO: 0.4 HC: 123 CO2: 14.6 O2: 0.47 Warm engine 2500 RPM

Low CO shows a good air/fuel ratio , low HC which indicates more efficiency , High CO2 tells us a good and efficient combustion and a little higher O2 readings which tells us the air/fuel mixture is not as rich as the 2 readings before .

CO: 1.6 HC: 250 CO2: 13.21 O2: 2.38 Idle, Rich mixture

High CO levels and high HC reflect on the rich mixture , CO2 levels a little less than the above reading which shows not as much efficiency in the combustion and high O2 shows not all the Oxygen is getting burnt .

CO: 0.07 HC: 230 CO2: 11.88 O2: 4.9 Idle, Lean mixture

Low HC and high O2 levels indicates Lean air/fuel mixture , even lower CO2 levels shows us the effiency is decreasing .Low and good CO readings.

CO: 3.349 HC: 1188 CO2: 9.09 O2: 9.34 Blipping throttle

High CO due to very rich air/fuel mixture , High HC shows us not all the fuel is being properly burnt , low Co2 which shows the effiency of the engine is deceasing and high O2 shows us a very very rich mixture and probably the most inefficient part of a normal operation .

CO: 0.157 HC: 2672 CO2: 7.28 O2: 11.03 Disconnect one spark plug

High HC , O2 shows us the fuel and air not being burnt in one cylinder , CO2 decrease shows the combustion effiency is falling ,CO levels are a little bit high but thats because a cylinder with no spark doesnt effect the CO levels.

CO: 0.068 HC: 188 CO2: 6.94 O2: 11.72 Disconnect one Injector harness

Good and low CO reading , low HC and high O2 shows us there is too much oxygen not being burnt and even lower CO2 levels indicates a very poor combustion .

CO: 0.550 HC: 195 CO2: 14.02 O2: 1.58 under load

A little bit high CO levels due to the rich air/fuel mixture , a bit higher than average HC which is because of the rich mixture , highest CO2 level which indicates the most efficient combustion period for this engine , higher than normal O2 reading can indicate that this not too much of rich mixture and still has enough Oxygen to burn all the fuel properly.

WS6

Toyota Soarer 1994 single wire ziconia switching sensor:

I back probed the plug coming from this sensor and which was located on the left hand side of the enigne on the exhaust manifold.

After engine has warmed up and in closed loop which we can tell this as it is in nomal cycling .

Maximum voltage is around 0.8 Volts

Minimum voltage is 0.2 volts

Cross counts were 7

Below we can see as we made the air /fuel mixture rich by a couple of sudden acceleration becuase usually this will make the system pump more fuel into the cylinder and makeing mixture rich.

The highest voltage I got was 0.85 Volts which was within manufaturer specs. each division is 0.5 Volts and time is 1 second.

Below we made the air/fuel mixture lean by reving the engine up to 3000 RPM and then a sudden deceleration will make the system to go into lean mixture. the lowest point was 0.05 volts and we can see the how it is going back to the normal cycle just at the end there .

Below we want to see how quickly the O2 sensor responds to changes and the easiest way is to do a sudden acceleration and see how quickly it changes ... we can see the voltage increasing from less than 0.2 Volts to higher than 0.8 Volts in less than 100ms which I think is a very good results

We can see that this sensor is in good working condition as all the results were within the specifications and had a response time and also clearly showed us and reflected the lean or rich conditions .

WS5

MAZDA FAMILIA 2000



Above are the information we could obtain from this vehicle .

Fault codes :
I checked on the scan tool but there were no fault codes recorded .

after lecturer intoduced the faults :
1st: turn on the car and check for fault codes 100 MAF , 110 IAT this will indicate the area .
2nd: turn on the vehicle and now compare the reading with the previous reading which we did earlier ... IAT was 25.46 deg/C and now 19.85 deg/C . MAF was 1.87 V and now 0 Volts
3rd: visual check the sensors and wires and noticed MAF and IAT sensor plug was not plugged in properly
4th: Repaired the fault by connecting the plugs properly and clear the fault codes using the function on the scan tool .
5th: Recheck the live data to make sure they are back to normal IAT 25.46 deg/C and MAF 1.87 Volts .
6th: recheck the system for any faults and none were recorded .

Live data is a very important, usefull also easiest ways to diagnosis a problem specially if there is no fault codes recorded . It is a good way to check the performance of the vehicle under different conditions where some faults could be hiding in ...

Parameters are as important as the live data because how would you know if this data you are getting is within the manufacturer specs (normal) ??? you'll have to compare the live data with the parameters to make sure that they are within the parameteres that is concidered normal for this vehicle .

Scan tool can aid us to check the live data against the parameters and point us in the direction we need to be looking ... it might not pin point where the problem is but its a good start for direction and even if the sensor is faulty after checking the circuit for bad connections , bad earth ... by comparing the live reading against the parameters

WS4

First locate a fire extinguisher close by incase of an accident

There are several different ways to relieve the pressure before installing a pressure gauge , I personaly prefere this method myself ... Remove fuel pump relay then start engine till it run out of fuel and stops then to double check crank the engine to make sure no fuel is left in the fuel lines ... This is a very tidy , quick and not messy and also not dangrous to get rid of pressure in fuel lines .

Hook up the fuel prssure gauge , turn on the car briefly and stop to check for any fuel leaks. we didnt have any fuel leaks so we move to the next stage ...

Fuel pressure with key on and engine off was 284 Kpa.

After turn on the engine for a couple of minutes and the pressure was 260 Kpa.

Also with the engine running clamp the fuel return line to record maximum pressure 490 Kpa.

To similuate wide open throttle we disconnected vacuum line going to fuel pressure regulator 310 Kpa.

To check residual or rest pressure we turned off the engine and watched fuel pressure for 5 minutes 250 Kpa.

To check the flow of fuel in the fuel lines and to make sure enough fuel is getting to our injectors 2.2 L per minute and also to check if it is within manufacturer's specification because too low will cause a lean combustion and too much would make it run rich .

Now follow the same step as the top to get rid of fuel line pressure so we can disconnect our gauges and put the vacuum lines and fuel lines back where they belong . double check for leaks and make sure the vehicle is safe and runs fine.

Symptoms :

Low fuel pressure :

This will cause the engine to run rough and cause it to misfire due to lean mixture and increase emissions of HC.

Low fuel flow :

This could be caused by a blockage in the line eg. fuel filter blocked , this will cause the vehicle to have a poor performance specially under high loads or quick throttle response is poor also as the injector runs out of fuel to inject in to the cylinder

High fuel pressure :

This would cause black smoke out of the vehicle exhaust which indicates rich mixture and high HC (unburnt fuel) to enter the atmosphiere ... engine would run rough at idle. it also can be caused by faulty fuel pressure regulator .

Faulty fuel pressure regulator :

This will also result in black unburnt fuel to come out of the exhaust and very rich air/ fuel mixture . Bad fuel economy , high HC emissions . it also can damage the cat convertor and O2 sensor if this problems carries on for a long period .

WS3B-4

Ignition primary against Injector pattern

Volt division primary : 50 Volts
Volt division Injector : 20 Volts
Time division : 5 mili seconds

The frequency of these two pattern is in ratio to each other because as the RPM increase so does the frequency of primary pattern and hence the increase frequency of the injector to provide the engine with fuel at the right time so it can increase the efficiency of the engine ,also correctly be ignited to provide maximum performance and produce minimum amount of emmissions .

WS3B-3

Oxygen sensor against Injector signal (petrol)

Volt division oxygen sensor : 0.5 Volts

Volt division Injector : 20 Volts

Time division : 5 mili seconds

When the O2 sensor voltage increase the ECU would see this as a rich mixture and to counter this decrease the dwell time (opening time) of injectors so less fuel is being injected( injectors staying open) and the mixture would become leaner

WS3B-2

RPM signal against Injector signal (petrol)

Volt division RPM: 10 Volts
Volt division Injector: 20 Volts
Time division: 5 mili seconds


As the we rev the engine up the amplitude and frequency of the RPM signal increases the dwell time of injector and frequency of the signal increases so it can provide right amount of fuel and at the right time inside the combustion chamber.

WS3B-1

Map Analogue voltage against injectors petrol

As the manifold pressure increases so does the injector dwell time and as the RPM increases so does the frequency of injectors working ... hence engine provides more fuel because there is more air inside the manifold , as the pressure increases inside the manifold so does the MAP output voltage.

Signal name: MAP analogue vs Injector pattern digital

Volt division: (MAP) 2 Volts

Volt division: (Injector) 20 Volts

Time division: 5 mili seconds

WS3A-5

WS3A-4

ECT

WS3A-3

WS3A-2

MAF analogue signal:

WS3A-1

WS3-7

Idle air control :

This is a solenoide which is controlled by the ECU . This solenoide controls the amount of air bypassing the throttle butterfly and entering the intake manifold to keep the car running when the engine is at idle and the throttle fly is not open to allow air inside the intake manifold so it can have sufficient air to keep the car running smoothly. It is a PMW and the frequency increases as the engine RPM increases and the On time gets smaller.

WS3-6

MAP Digital :

This sensor calculates the pressure inside the intake manifold so the ECU knows how much air is going inside the engine so it can adjust the air/fuel ratio accordingly . Some people like refering to this sensor as Vacuum sensor . We can see in the photo above there is high vacuum in the manifold therefore a low output volatge but as we rev the engine up the air inside the intake manifold increases due to the throttle butterfly allowing more air past it this means less vacuum inside the manifold or more pressure inside the intake manifold , consequently this will increase the output voltage of signal wire back to the ECU. which we can see as the peaks on the graph above.

WS3-5

RPM Hall Effect Crank or Cam position sensor:

This sensor provides the ECU information about the position of the crank and Cam shaft and in relation with the TDC . ECU would know which cylinder is in which cycle and where abouts are they in their stroke cycles by this sensor input and the TDC reference mark . It produces a digital signal same as the above and also dtermines the dwell time of the primary circuit and also the firing period . as the engine RPM rises the frequency increase and dwell time and firing preiod decreases.

WS3-4

O2 sensor:
The O2 sensor works in comparing the amount of oxygen in the exhaust and amount oxygen in the ambient air ... above we can see the oxygen sensor is operational which normaly has to reach 300 deg/C and after that ECU goes in to closed loop which means the ECU uses oxygen sensor to see if the air/fuel mixture is lean or rich and if rich it will make it leaner and when lean it will make it rich and we can see this cycle in the above photo.

WS3-3

Ignition Primary pattern :


This pattern is a good way to check the condition of the ignition circuits . It also uses string theory so as the firing voltage increase the burn time decreases and vice-versa.

Firing voltage: The voltage or push needed for the spark to jump the spark plug gap .

Burn voltage: Voltage needed to maintain an arc or spark between the spark plug electrodes so it can burn all of the fuel in the combustion chamber.

Burn time: The length of time in which the arc or the spark maintained , its a good indication of the state of the secondary circuit components (spark plugs , HT leads , King lead , distributor cap , rotor and secondary ignition coil )

Dwell time: The length of time in which the primary circuit is grounded (turned on) for prior to the each spark . It is to build enough magnetic field in the primary so then after collapsing it can induce a high enough voltage in the secondary windings .

WS3-2

RPM magnetic pick up distributor:

The frequency and the ampiltude of the voltage changes as the magnetic teeth speed increases or decreases . As the teeth magnetic field approaches the sensor it creates negative voltage first then as it gets next to the magnet there is no vltage created because no magnetic field are being crossed , as the magnetic teeth field starts going away from the magnetic pick up sensor it craetes positive voltage which we see on the graph above or the video below will show as we rev the engine up the frequency and amplitude increases rapidly.

WS3-1

Petrol Injectors:
At the voltage supply the injectors are closed because they havent been earthed out by the ECU yet at the point where we have injector opening the ECU earths out the injector and the solenoide inside is energised to open the injector and the Back EMF is produced as the magnetic field collapses on itself which creates a hight peak ... to keep the injector open only a little bit of energy is needed compare to when they need to be opened . after the injector is closed the voltage goes back to supply voltage till the next time its earthed out by the ECU to be opened and this opening and closing is also known as PWM. which is sent from ECU .

WS2

-Toyota 4Age

By looking at the vehicle workshop manual we can obtain the correct pin to bridge and with the key on we can put the car into diagnostic mode , I really like this as we dont need expensive scan tool only a jumper wire , also so easy to use as in which direction you should be looking at , It does not always tell you what we exactly need to check or where to look but its always a good start .

- After looking at the workshop manual ... it states the ignition should be in the ON position and bridge terminal TE1 and E1. and this puts the car into diagnostic mode and we can use the car's own ECU it can tell us what faults it has logged on its memory .

- After fault codes were put in by the tutor we put the car in to diagnostic mode and the codes we found were : 2 & 7 these faults made the car run very rugh and keep turning off at idle .

There were also 3 & 5 which we got because we had the ignition module unplugged ( code 3) and unpulging engine RPM sensor inside the distributor ( code 5)

- By looking at the list below we can see what does each code number means

- After doing the visual inspection at faults found : I found the TPS sensor plug was not in properly and also the vacuum sensor plug was not in properly so the ECU was not getting good signal from these sensors .

- I repair these faults by making sure they were plugged in properly .

- To check and make sure I turned the car on and now it was running with out a problem and was running smoothly at idle and also when reved up .

- To clear the fault codes I disconnected the battery and left it for a couple of mins and then connected the battery back to the vehicle . I put the jumper wire back in TE1 and E1 and turned the ignition on .

code 1 means everything is normal and there are no faults detected by the ECU

- Code 2: Interupted signal from the manifold vacuum sensor . This fault will cause the vehicle to not run smoothly as the ECU doesnt know what the vauume pressure inside the intake manifold is ... also how much engine load we have specially when driving , not so much at idle and how much load its carrying and might struggle going up hill since it has no value from the vacuum sensor . It will cause the engine run poorly and to make the engine emission to rise because its not running at the optimum condition .

- Code 7: Interupted signal from the TPS . This fault will cause the engine run very poorly as the ECU has no idea what the driver intend is and how much air is coming inside the intake manifold and whether the diver is accelerating fully or half way and what he wants to do exactly . This will cause the engine to run poorly at idle or even more when driving and cause the emissions to rise as the ECU can not find the optimum condition for the vehicle.

- We can also check the supply wire voltage , check the ground by Voltage droping the earth wire with a good ground e.g negative post of the battery . also we can check the signal wire and make sure it is changing in the right manner and check all these information with manufator spec to see if it is within specified spec.

WS1

Petrol Fuel Injector Testing :

Checking the voltage at the injectors and the battery

Make : Toyota Model : 4AFE (Grouped injection)

- After turning the engine on we can listen to the injectors opening and closing which sounds more like ticking than any thing else . I put the end of the screw driver on the body of the injectors and the plastic handle of screw driver on my ear and could hear ticking from the injectors . This shows each injector is opening and closing and as long as there is fuel available to the injectors , it also means that they are injecting fuel into the cylinders and they are opening and closing . All injectors OK and could hear ticking from all 4 .

- Bychecking the voltage at the injectors we can also make sure they are getting the right voltage which is the battery volatge ( 13.50 Volts) and this will show if there is high resistance in the circuit and no poor connections. These results are within the manufactorer spec which is good under 0.1 volts from the battery supply .

- Another way of checking to see if injectors are working properly is to back probe each injector and hook up a LED tester to it ... as the ECU grounds each injector so those the LED tester and it consequently turns the LED on ... this happens so quickly that makes it look like the LED is always on especially when we rev the engine up . This can show if the injector is repetetive is in order and is getting a good PWM.

- By using the multimeter set to duty cycle we back probe the injectors and connect our multimeter to the injectors . we can see how much of the time they are staying open at idle . shows that the injectors are staying opened roughly around 2.2-2.4% of the time to spray petrol in the engine . which shows that the engine is running lean at idle.

- Having the multimeter on the same setting and back probed to the injectors we rev the engine up to see if the duty cycle changes and by how much . This results show that when we rev the engine up our injectors are staying open longer to spray more petrol as we need more to be able to increase the RPM , ECU does this to comply with the driver intend which picks up from TPS , MAF ... My results show when we accelerate the engine with a short fast throttle , the injectors are staying open 34-37 % of the time which shows more of a richer mixture than idle .

- Now by setting the multimeter to Hz and still having it hooked up to the back of the injectors
we can see the frequency of how many times per second our injectors are opening and closing . we first do this at idle . Our results show that the injectors are opening and closing 47.5-48.2 Hz times they are opening and closing per second . This shows a lean mixture.

- We now repeat the steps above but reving the engine for a short time to see if the frequency of the injectors are changing or not and by how much . Our results show that the frequency has more than doubled and that also tells us the injectors are opening and closing 112.7-116.1 Hz times per second . this tells us that we have richer mixture since the frequency of the injectors opening and closing has more than doubled .

- Now using this formula " Pulse width ms = (% duty cycle x 100)/frequency"
would show us how long in ms the injectors are staying opened .

since we have grouped injection I am doing cylinder 1&3 and 2&4 together .

At idle :

Cylinder 1 & 3 :

Pulse width ms = (2.2 x 100) / 47.5
= 4.63 ms

Cylinder 2 & 4 :

Pulse width ms = (2.4 x 100) /48.2
= 4.98 ms

Reving up :

Cylinder 1 & 3 :

Pulse width ms = (37 x 100) / 112.7

= 32.83 ms

Cylinder 2 & 4 :

Pulse width ms = (28 x 100) / 116.1

= 24.11 ms

Conclusion :

This is a very good way to check how good they are working . Easy and faster way to check injectors with out pulling them all out and if we dont have pattern tester or flow rate tester then there is actually no other way to test weather they are working and how long they are being opened for in realtion with RPM .

Building a simplify ignition module

Wiring up an ignition system

Above also similar to 3rd diagram is a coil over ignition system which each spark plug would be using their own coil , and sometimes even their own ignition module (darlington pair ) built in one and located on top of each spark plug .

Above is a wasted spark ignition system consisting of function generator to trigger the module , and darlington pair (ignition module) wasted spark coil and 2 spark plugs.

Above is an ignition module (darlington pair) functin generator to trigger the module , coil and a spark plug .

Above we have an ignition module (darlington pair) disributor to trigger the module , coil and a spark plug .

Testing ballast resitors

Checking ballast resistors is very easy ... unfortunatly the ones we used didnt have any idetification still written on them so we couldnt get any specs .
Ballast No1 measured resistance was 1.4 Ohms.
Ballast No2 measured resistance was 1.5 Ohms .
most of the ballast resistors have a similar resistance so if significantly higher than 1.5 Ohms or signifiacntly less can tell us there is an issue with this resistor but ofcourse if we had the spec it would have been much easier to do this ...
Also none of these ballast resistors are serviceable.

Wasted spark coil pack

checking the resistance of secondary windings because it was not possible to check the primary

Coil #1 secondary was 6.91 Kilo Ohms

Coil #2 secondary was 6.82 Kilo Ohms

Pin outs :

1= + positive supply 12 V

2= - negative earth

3= Signal 1

4= Signal 2

Testing ignition coils off-car

Above shows how to check the internal resistance of the primary windings.

Below shows how to check the internal resistance of the secondary windings.

Testing Ignition coils : I could only get these information of the coils and the primary and secondary spec was not visable and only the number and volatge rating was still on the coils




Using a multimeter I recorded the default error of the multimeter which was 0.1 Ohms and took it out of the readings I got so I could get an accurate reading. I first checked the primary windings and recorded it and then the secondary winding following the diagrams above ... then did the earth leakage test from negative terminal to the body of the coil and the result was OL which shows there is no circuit between earth and the body so no leakage (good). Its very hard to be able to tell if these coils are in good condition as we dont have the manufaturer specifications to compare them with our findings and also to see if they are within the manufaturer specs . I dont think these coils need serviceing.

Injector testing off-car

Testing injectors:

To check the injectors and to see if they are in good working condition we measure the resistance in their windings to make sure they are in good condition. The manufacturers specification for the types we were using (without resistor) was 14-17 Ohms. they all seemed to be in good working condition. Earth leakage by checking the resistance between the earth terminal and body of the injector , This should be OL which means the there is no part of the injector(specialy windings) has not been earthed out thru the body injector. If there is a reading between the earth and the body that means the injector is faulty and is shorting out thru the body which means it needs to be replaced.

Now we have wired up the injectors to a power supply and I can hear them ticking as I turn the power on and off. This shows that they are opening and closing in the right manner and internal parts are in working condition.

Other engine problems that could give us the same results as an injector not working could be :

Fuel pump siezed or not working , Fuel filter blocked , Fuel line broken or no petrol in the tank.

Next test is injector spray pattern test to make sure they are spraying an even cone shape without any distortion , this is to make sure the fuel is getting fully atomised and fuel is not just running in the manifold.

Next test is to check the Delivery volume of the injector and to compare this results against the manufaturer spec but a little variation between the injectors is ok. If the flow is restricted within the injector, the delivery volume is reduced therefor that cylinder will run lean.

An other and the last test we did was the injector leakage(dribble) test. We do this by applying full line pressure to the injectors without operating them . Fuel leakes and passes the seats and will drip from the injector nozzle... Most of the manufaturer spec specifies only 1 drop per minute is acceptable and any more that is not and needs to be rectified .

Hall effect type sensor off-car

Hall effect type sensor which enables the ECU to know the position of the camshaft and also tells ECU where the reference point (TDC) is .
It only consists of 3 major parts , Magnet, steel chopper plate, Hall integrated IC.
As the window (gap) in the plate comes between the magnet and Hall integrated IC which are only milimeters apart it creates voltage a digital signal . Depending on the manufaturer the primary Ignition is depended on the sensor . dwell time could be when the gap between the magnet and Hall IC is blocked and the fireing time when there is a window between the magnet and Hall IC... therefor this signal is vital for this types of engine to even start.