Testing Ignition Systems

this practical required me to test components of an igntion system on a car,namely Toyota Cynos 1993. I removed the high tension leads and the spark plugs off the car for analysis. I also had to check the distributor on its condition aswell as setting the timing and testing the vacuum advance.


As required i did all the pre-proceedure tests i.e checking the oil levels through the dipstick located in the engine, the coolant level, the fuel(fuel gauge ofcourse) and the battery condition.


Battery test: Unloaded:12.33Volts.... Cranking:1.05 Volts.... Recovery:12.39 Volts




I carried out a continuity test on the High Tension leads.On inspection, two of the High Tension leads to spark plugs 1 and 3 had faults. Lead 1 had no reading when i did a continuity test on the leads,indicating a short and lead 3's wire had worn out, so they needed replacement to ensure efficiency.  The other two passed with resistances of 15KΩ and 14KΩ. this is crucial as the  secondary side of the ignition system carries a very high voltage.
The distributor check revealed that the contact points in the distrubutor cap had worn out and this was causing bad contact that resulted in misfiring in the engine. The rotor's contact effectively had worn out so i got a new distributor cap and rotor as replacements to fix the problem.


The following video is of me testing the king lead with a spark connected to it directly and measured with a multimeter set to volts,obtaining a reading of 11.58V. this cleared as in good working condition

I then removed the spark plugs with from the cylinder to check the condition visually.it is important to remember to the order in which they came out for when re-fitting them back.By inspecting the condition and colour of the electrodes of the spark plug, the condition of the combustion burning can be determined

 http://www.motorcycleinfo.co.uk/resources/6795/assets/images/FAQs/electrics/check_spark_plug_condition.jpg

the above link is to a chart similar to the one i used to cross reference the spark plugs condition and they were in good working condition so i refitted them as i had taken them out.

Checking The Timing

with help from my class mate,i used a timing light to check the intial timing,looking at the T.D.C timing marks. the light is clamped to spark plug number 1 lead and the battery, while engine is running.It is pointed to the crank pully,as the firing of sparkplug 1 and the crankshaftpulley timing marks are related.Gradually increasing the engines R.P.M's until the timing marks advance from the intial timing mark,till it reaches its maximum advance and return it to normal idle.the number of degrees it moves from initial to maximum is the degree of mechanical advance.if the timing off,to adjust you loosen the distributor clamp so you are able to move it.Turning the distributor clockwise retards the spark; turning it counterclockwise advances the spark. then increase the R.P.M's again then watch the marks on the crankshaft with strobe light.The markin should advance,then turn the distributor to the spec maximum degree advance.return the engine to idle and then shut the engine off and tighten the distributor,the timing should be adjusted after this proceedure.

OFF CAR IGNITION

i measure six high tension cables for their length and their resistance.

33

56.5

57.5

67

82

94

Length in CM’s

12Kohms

13Kohms

14Kohms

15Kohms

15Kohms

15Kohms

Measured Resistance

No faults	No faults	No faults	No faults	No faults	No faults	Visual Inspection
p	p	p	p	p	p	Pass or Fail

Next was to check the ignition coils.below is the results for the two coils i measured.following that is the video of the coil circuit with a switch and another one with the distributor connected. the last video simulates the events in the ignition system on car as the distributor passes on the charge to the spark plugs.

Coil Specifications:

1st Coil Part Number …f-088 2^nd Coil Part Number 16c6..

1st Coil Voltage …12V.……………….. 2^nd Coil Voltage …6V….………………..

1st Coil Primary Ω ….……………….. 2^nd Coil Primary Ω ….…1.4Ω …..

1st Coil Secondary Ω ……………….. 2^nd Coil Secondary Ω ……7.54KΩ

off car i tested an ignition coil with a ballast resistor and high tension lead with a spark plug connected.

the spark of the plug would indicate the coil working.

i also tested the ballasts' resistance and it was 1.4 Ω

VACUUM ADVANCE TEST

 the following videos are of the vacuum test i did off car.

Alternator Testing

I took apart an alternator today to test and repair it. to dismantle the alternator, i removed the "B" nut and insulator and the nuts off the cover exposing the brush holder, voltage regulator and rectifier which i unscrewed and took off to perform the tests.
First test was the rotor winding earth leakage test. with a multi meter,set for 20M Ohms range, i put the positive on the slip ring and negative on the rotor shaft and got a readin of 1 (or infinity) which is a pass.
Following that was a rotor winding continuity test. with the meter on 2 Ohms range with both leads on the slip ring with an actual resistance of 2.8 Ohms,which is a pass.
On the same Ohms range, i measured the stator earth leakage. Placing the black lead on the common terminal of the stator winding,i measure the other 3 windings one after the other, all having a resistance of 0.1 Ohms. After was the stator winding earth leakage test,placing the red lead on the common terminal and measuring the other 3 with the black lead. To pass it had to read infinity on the meter,which it did.

 below is the alternators rectifier. in diode test mode,the common lead goes to the B terminal with the positive touching each of the P diodes for a reading of 0.5V .with the leads reverse it was 1(infinity)
with the common lead on the E terminal ,the red touchin each of the P diodes the reading was 1
with the leads reversed it was 0.7 V

the voltage regulator

for this test i had to match the regulator type in the manual for testing regulators. Using a transpo regulator

tester, i obtained the following results : in field setting A at a voltage of 12, the set point was 14.5V.

Below is a stator winding earth leakage test followed by a stator earth leakage test.

TEST SCHEDULE AND REPORT SHEET

1. Using the vernier calipers supplied check the length of brush protrusion at the centre of the brush holder.

Minimum allowable length 5mm

Actual length 6mm Pass

2. Check the condition of the rotor by carrying out following checks

Rotor winding to ground test1 Pass

Rotor winding internal resistance test 2 Pass

3. Stator winding internal resistance test Reading……0.1…… Pass

Reading……0.1…… Pass

Reading……0.1…… Pass

4. Check stator for grounding Reading…0.1……… Pass 

5. Check bearing condition (Noisy or Quiet)

Front …quiet……….. Pass

Rear…quiet………… Pass

1. heck operation of the regulator Fig 7

Set point……12……… Volts

Reading 14.5 Pass 

Short Circuit Light MUST BE OFF Pass l

Large red light should come on and stay on Pass 

Small red field light should flash continuously Pass 

2. Check the diodes in the rectifier

Positive Bank

Common Lead on “B” (1) ......0.5.V............. (2) ..0.5..V................

(3) .....0.5.V.............. (4) ....0.5..V..............

Positive Lead on “B” (1) ......1.............. (2) ..........1..........

(3) .......1............. (4) ............1........

Pass

Negative Bank Common Lead on “E” (1) ........1............ (2) .....1...............

(3) ........1........... (4) ......1..............

Positive Lead on “E” (1) .........0.5........... (2) .......0.5.............

(3) ..........0.5.......... (4) .......0.5.............

Pass 

TESTING ON CAR


TOYOTA CYNOS 1992.


Required for this are...high rate discharger , digital multimeter and an inductive clamp ammeter.
Preliminary checks i did was to ensure the ignition system was disconnected to ensure the car would start,a visual inspection of the connections and warning lights were functioning properly. 


No Load Test
Battery Open Circuit Voltage -  12.69 Volts


Voltage Regulator Spec( Toyota Cynos) - 14.5 Volts


Voltage Regulator Reading under load - 14.3 Volts

No load Amps output :

used a Clamp Ammeter ,clamped over either the positive or negative terminals

 Carburettor.....   5 to 12amps

Fuel Injected .....10 to 18amps

Reading..... 14 Amps which is a pass

FUELS

TESTING DIESEL INJECTORS

in this practical, i was required to test four diesel injectors.

the tasks that i completed were observing the spray patterns, checking for leakages and repairing any faulty ones.

we used a spray pattern tester which used a hydraulic fluid to simulate diesel

above is one the four diesel injectors used. to perform the test i fitted the injector onto the tester like below

the tester was already preset for this test but it is adjustable to how you want to perform the test.basically the tester applies air pressure to the injector like in a car and the spray pattern which the fluid forced out has shows if it is good for further use. of the for that i tested only one had a pattern that was off,more like a squirt and i changed the needle valve to fix the problem

below are the results i obtained during the test

Injector1	Failed the spray test. Disassembled the injector and refitted needle valve and worked 132 bar
Injector2	Passed spray test 209 bar
Injector3	Passed spray test 174 bar
Injector4	Passed spray test 165bar

EMISSIONS




40% of the planet's air pollution is attributable to the burning of fossil fuels (Petroleum). It is said
that the motor vehicle produces 50% of man-made hydrocarbons, 60% of the carbon monoxide
and 40% of oxides of nitrogen. The modern approach is to reduce the exhaust emissions while still
retaining the maximum fuel efficiency from the engine.(UNITEC-4843 Theory Emissions pdf)
The four main gases looked at for emissions are Hydrocarbons, Carbon Monoxide, Carbon Dioxide and Oxygen


Because of this,regulations have been put into place to reduce emissions and motor vehicle manufacturers are required to follow these. These requirements include catalytic convertors which,without going under change itself converts gases emitted from the engine exhaust into more environmentally friendly gases, e.g carbon monoxide converted to carbon dioxide.

Oxygen Sensors which are mounted to the exhaust manifold calculate the amount of oxygen in the exhaust gases calculates the air-fuel ratio and passes this information to the ECU. Oxygen reacting with the ceramic material that makes up the sensor at high temperature. This what determines if the mixture is rich(low Oxygen,higher fuel) or lean(higher Oxygen,lower fuel).

Positive Crankcase Ventilation(PCV) which routes the gases back into the intake system and to the combustion chamber to burned up.It is a one-way valve placed in the valve

cover or side of the block. It is connected by a tube to engine vacuum at the base of the carburettor or intake manifold.

TESTING FOR EMISSIONS

we carried out emissions tests on a car with a carburetor and EFI. The 4 Gas Analyzer test measure the levels of the emitted gases after combustion.

the pictures were taken as the tests where carried out and the results for the Carburetor and EFI engines are listed after.

TESTING EMISSIONS ON A CAR WITH A CARBURETOR

ACTUAl before adjustment                                                    INDUSTRY STANDARD

H.C.        233 ppm                                                                       5 to 30    H.C ppm

C.O.       1.921 %                                                                    0.05 to 0.5   C.O %

CO₂       8.56 %                                                                         13 to 15.5   CO₂ %

O _{2          7.50} %                                                                        1.00 to 3.00   O ₂ %

Now test an EFI vehicle and record the results

ACTUAL                                                                               INDUSTRY STANDARD

H.C. 159 ppm                                                                           H.C 100 ppm

C.O. 0.720 %                                                                              C.O 0.300 %

CO₂ 14.07 %                                                                                        CO₂ %

O _{2 0.  83}  %                                                                                             O ₂ %

battery testing

Battery testing practical

for this practical, a 12 volt battery, digital multimeter, hydrometer, high rate discharge tester (load tester), digital battery tester, safety glasses, safety equipment were required.

The battery used was a Champion 126HD with 310CCA. First thing I did was a visual inspection of the battery terminals and leads for any corrosion or any leakage. Found none
• next I did a visual check of the electrolyte levels and they were okay.
  
  
• next was an open circuit voltage test. before this test I removed surface charge,turning on the lights for a minute to do so. In the volts DC unit on the multimeter the batterys charge was 11.50 V which is less than 50% charged required to continue testing
  
  
• a specific gravity test was next. This required the use of a hydrometer, inserting it the cell's electrolytes.i wore safety glasses a safety precaution. With the hydrometer inserted in the cell, squeeze the rubber top of it and release to allow just enough water to make the floating indicator float. The reading is taken at level for a precision. 
  the specifications and the results table are listed below 
  
  

  
  1.240 – 1.260 = 100% Charged

  1.210 – 1.240 = 75% Charged

  1.180 – 1.210 = 50 % Charged

   1.150 – 1.180 = 25 % Charged
  
  

  Cell	1	2	3	4	5	6
  Reading	-	1300	1275	-	1280	-
  Colour		murky	murky		murky

  
  
  This battery failed the specific gravity test and the open circuit voltage test so I couldnt use it further
  
  
  To continue the High Rate Discharge Test I then used another battery AA brand with a 330CCA
  Required for this test was a load tester which I would apply a current that half of the battery's cca, i.e 165CCA.:
  Connecting the load tester to the battery terminals positive first,i applied the load,holding it for 20 seconds to get a reading : 11.44 V held the battery passed the test. the result of this test indicate
  the current that is used when the car is switched off.
  
  
  next a parasitic draw test,which requires me to test the battery in series with a digital ammeter.
  The amp draw was 0.02A which was a pass(specification 0.02A-0.05A)
  
  
  Then I used a digital meter test . This is powered by the battery being tested so a failed or very low voltage battery would not be suitable for this test. The battery voltage should appear in this case it was an OCV of 12.68 V. Scrolling up or down with the arrows on the meter, select to put the batterys CCA (330) and select test. Pass indicates a good battery..Ch to charge it or Fail which means that.My result was pass.
  
  
  the above test showed the battery was in good condition and I still use it in my car even today

SOME TERMS OF ELECTRICTY WE HAVE LEARNED

Electrical terms

here are some of the terms we work with through out the course

Volts (V)..the force or pressure required to move electrons in a circuit

Amps (I or A)..unit of current..the more the electrons flowing the larger the current.

Ohms(R)..resistance..the units in the measuring the resistance to the flow of electrons

Ohms laws

if provided 2 of the above values you can calculate the 3^rd using Ohms law.

V= A x R A = V/R R = V/A

Voltage Drop is the amount of voltage that has dropped since leaving the battery.

Power is measured in Watts...

W = V x I V = W/I I = W/V

There are several types of electrical circuits but we are familiar with:

series..created when components of a acircuit are connected one after the other.the current stays the same but the voltage is used up as is flows through the circuit.

Parallel.. each component of this circuit get the same voltage as they are branched off from the source of power.usually of a high current,the amperage is divided by each branch

(http://t3.gstatic.com/images?q=tbn:ANd9GcQ-bQshTCWTN20VqCIZb7p_RJo4536TZVA2NZRmryk66EewMz5qfw&t=1)

Compound...this is part series, part parallel.any calculations for this circuit type requires the parallel part to be measured first.

(http://hop.concord.org/e1/e1ma3.html)