Laboratory manual experiment

Setting Ignition Timing

• 
  Setting the ignition timing on the Z32 is simple but VERY vital to good performance and longevity for the engine.
  

• 
  Inductive timing light
  
• 
  10mm wrench or ratchet.
  
• 
  12mm wrench or ratchet.
  
• 
  Short high-tension wire (Honda spark plug wires work great)
  
• 
  A Consult interface (Nissan Data Scan, Consult, ECUTalk, etc) is greatly preferred, but not totally required.
  

• Warm the car up to operating temperature. It must be totally warmed up and should be idling at a normal RPM (around 750 RPM). Then shut it off.

• Disconnect Cylinder 1's coil pack connector.

• Connect a high-tension wire to the coil pack, and the other end to the spark plug. This effectively creates an extension for Cylinder 1's coil pack.

• Loosen the three 10mm bolts on the Crank Angle Sensor, but do not remove them. It should be loose enough to rotate by hand, but not so loose that it will spin by accident.

• Start the engine, and again ensure it's idling normally and is fully warmed up.

• If possible, use a computer to verify that the ECU is timing for 15° (BTDC). When fully warmed up and idling, the ECU will time for 15°BTDC, but in many cases, other factors can cause the ECU to set the timing elsewhere (for example, an improperly adjusted TPS will cause the ECU to modify the timing).

• You can actually still set the timing if the ECU is sitting at, say 20°. It shouldn't be sitting at 20°, but the important thing is that the physical timing matches what the ECU is expecting.

• Connect the inductive pickup of the timing light to the high-tension lead installed on Cylinder 1's coil pack.

• Ensure that the timing light is set for 0° advance (if applicable), and aim it towards the crank pulley from the 10-11 'o'clock position.

• When the trigger of the timing light is depressed, it will flash each time the cylinder fires. As the engine rotates, the mark on the crank pulley passes by the markings on the cover above it. The timing light's flash allows you to see, for a brief instant, when the cylinder is firing in relation to the rotation of the engine, as the mark on the crankshaft aligns briefly with a number on the cover above it.

• Gently rotate the CAS so that the timing mark on the crank pulley "lands" at the 15° mark on the cover above it.

• Shut off the engine.

• Tighten down the 3 10mm bolts holding the CAS to the bracket. It needs to be snug, but keep in mind that the bracket is aluminium.

• Remove the high tension wire, and reinstall the coil pack like normal.

1. 
   Explain the checking of ignition timing.
   
2. 
   Explain the method of checking advance and retard.
   

• 
  To conduct voltage drop test.
  
• 
  To conduct no load test.
  

• 
  Lucas starter motor,
  
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  Fully charged battery,
  
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  Solenoid switch,
  
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  Ignition switch,
  
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  Volt meter,
  
• 
  Tachometer,
  
• 
  Hand tools.
  

• 
  The function of the starter motor is to crank the engine. The performance of the starting motors depends upon the system voltage. But system voltage is affected by underside resistance in the starter circuit in such place as the cable solenoid & grounds.
  
• 
  The most accurate method of analysing the starter circuit for excessive resistance include the use of voltmeter as sown in fig. Voltage roaming of a certain section of the circuit are taken & transposed into interpolation of resistance for the section.
  

• 
  Place the voltmeter leads across the battery according to polarity cranks the starting motor and record the readings keep the mind that higher the voltage drop across the battery it includes the battery performance.
  

• 
  Connect one lead of the voltmeter to the ungrounded terminal of battery and other leads to the terminal of starting motor. Crank the starting motor and tack readings keep in mind that voltage drop across insulate side should minimum. It should be not higher than 0.4 V.
  

• 
  Connect the voltmeter lead on the starter frame. Connect the negative voltmeter lead to the negative battery terminal. Crank the starting motor, which the voltmeter reading should not be above 0.2 V.
  

• 
  If the insulated side is above 0.4V, look for loose or dirty connection in adequate cables or a faulty switch or solenoid somewhere between the points tested.
  

• 
  If the voltage drop starter is less than 9.6V, there may be drowns too much resistance across the insulated side & the ground side check with the test.
  
• 
  If the voltage drop across the ground side is more than 0.2V, there look for loose or dirty ground cables or dirty loose starter mounting.
  
• 
  If the battery reads lower than 10.20V, but not lower than 9V, it may be drawings too much current. The battery need to be recharge.
  

• 
  Connect the starter motor as shown in fig. crank the motor and show the rpm under without load condition with help of tachometer. Measured rpm should be comparing with the manufacturer specifications.
  

• 
  If the current & speed are both low, it is an indication of high resistance in the internal connection. This usually caused by poor brush contact with commutator’s.
  
• 
  If current is high and speed is low it is an indication of drop on the armature, which may be caused by worn bearing, bend shaft, insufficient and play or by excessive bush tension.
  

• 
  Always release the starter switch immediately after completion of test.
  
• 
  Don’t operate the starting motor more than 30 seconds. If engine reduce to start for some minute, then start again.
  
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  During the test, battery should be healthy.
  
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  During the no load test, starter motor should be mounted on a holding fixture or vies.
  

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  When starter is operate and if fails to rotate,
  

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  Discharge or defective battery.
  
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  Excessive voltage drops in starter circuit due to loose or oxidised battery terminal.
  
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  Starter terminal or carbon brushes contact with commutator.
  
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  Defective solenoid switch.
  
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  Defective armature & field coil.
  

• 
  Recharge the battery/ check with complete gauge
  
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  Check & rectify starter circuit, clean the terminal, tighten all connection.
  
• 
  Spot the earth shoot faulty & rectify.
  
• 
  Replace solenoid switch, armature or field coil.
  

• 
  Alternators generate electricity by the same principle as DC generators, namely, when the magnetic field around a conductor changes, a current is induced in the conductor. Typically, a rotating magnet called the rotor turns within a stationary set of conductors wound in coils on an iron core, called the stator. The field cuts across the conductors, generating an electrical current, as the mechanical input causes the rotor to turn.
  
• 
  The rotating magnetic field induces an AC voltage in the stator windings. Often there are three sets of stator windings, physically offset so that the rotating magnetic field produces three phase currents, displaced by one-third of a period with respect to each other.
  
• 
  The rotor magnetic field may be produced by induction (in a "brushless" alternator), by permanent magnets (in very small machines), or by a rotor winding energized with direct current through slip rings and brushes. The rotor magnetic field may even be provided by stationary field winding, with moving poles in the rotor. Automotive alternators invariably use a rotor winding, which allows control of the alternator generated voltage by varying the current in the rotor field winding.
  
• 
  Permanent magnet machines avoid the loss due to magnetizing current in the rotor, but are restricted in size, owing to the cost of the magnet material. Since the permanent magnet field is constant, the terminal voltage varies directly with the speed of the generator. Brushless AC generators are usually larger machines than those used in automotive applications.
  

1. 
   Frame or Housing
   
2. 
   Rotor
   
3. 
   Slip Rings
   
4. 
   Stator
   

• 
  The Diode Rectifier Bridge is responsible for the conversion or rectification the AC voltage into DC voltage. Two diodes are connected to each stator lead. One is positive the other negative, because a single diode can block only the half AC Voltage. Six or eight diodes are used to rectify the AC stator voltage to DC voltage. Diodes used in this configuration will redirect both the positive and negative polarity signals of the AC voltage to produce DC voltage.
  
• 
  This process is called 'Full - Wave Rectification'. Diodes are used as one-way electrical check valves. It passes the current in only one direction, never in reverse. Diodes are mounted in a heat sink to dissipate the heat generated by the diodes. Diodes redirect the AC voltage into DC voltage so the battery receives the correct polarity.
  

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  The regulator will attempt to maintain a pre-determined charging system voltage level. When charging system voltage falls below this point, the regulator will increase the field current,
  
• 
  Thus strengthening the magnetic field, which results in an increase of alternator output. When charging system voltage rises above this point, the regulator will decrease field current, thus weakening the magnetic field, and results in a decrease of alternator output.
  

• 
  It is carried out with the help of testing lamp or multi meter.
  
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  Connect the prods of multi meter with the rotor winding and segment.
  
• 
  Check the multi meter for continuity if it show 1 then it indicates that the winding is continue if it shows 0 then it indicates the winding is distorted.
  
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  Connect the cable of lamp with the rotor and other and to the battery.
  
• 
  If the lamp lights it indicates the winding is continued.
  

• 
  In this test testing lamp is use for ground test.
  
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  Connect the positive terminal of the lamp with alternator winding and negative terminal of the lamp with the field coil.
  
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  If the lamp lights then indicates the alternator is grounded and if lamp doesn’t light then it is ungrounded and it is accurate.
  
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  Multi meter is also use for ground test.
  
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  Connect the prod of multi meter insert the positive prod with terminal of alternator and other negative prod with the body.
  
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  If the multi meter show 1 reading then it indicates the body is grounded.
  
• 
  In this way ground test is done.
  

• 
  The alternator output test checks the ability of the alternator to deliver its rated output of voltage and current. This test should be performed whenever an overcharging or undercharging problem is suspected. Output current and voltage should meet the specification of the alternator. If not, the alternator or regulator may require replacement.
  
• 
  A sun VAT – 40 tester, similar tester, or a separate voltmeter and ammeter can be used. Follow the manufacturer’s instruction when using special tester, although most are operated similarly. The following steps outline a typical procedure for performing the alternator output test using a sun VAT-40.
  

1. 
   Prepare the tester:
   

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  Rotate the load increase control to OF,
  
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  Check each meter`s mechanical zero. Adjust, if necessary.
  
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  Connect the tester load leads to the battery terminals, RED to positive, BLACK to negative.
  
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  Set the selector to INT 18V.
  
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  Set the selector to #2 charging.
  
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  Adjust ammeter to read ZERO using the electrical zero adjust control.
  
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  Connect the clamp-on amps pickup around the battery ground (-) cables.
  

2. 
   Turn the ignition switch to “ON” (engine not running) and read the amount of discharge on the ammeter. This is a base reading for current the alternator must supply for ignition and accessories before it can provide current to charge the battery.
   
3. 
   Start the engine and adjust the speed to about 200rpm. Some models may require a different speed setting.
   
4. 
   After about 3-4 minutes, read the ammeter and voltmeter. Add this ammeter reading and the reading found in step 2 (engine not running).
   

5. 
   Remove ground from terminal.
   
6. 
   With the engine running at specified speed, adjust the load increase control to obtain the highest ammeter reading possible without causing the voltage to drop lower than 12 volts.
   
7. 
   Read the ammeter.
   

• 
  As we know the alternator output we can also check through separate voltmeter and ammeter or using a multi meter. To check the output of the alternator using multi-meter, it can allow this operation without removing alternator from the car. We can follow these steps to check the output of the alternator.
  

1. 
   Check the Battery terminal connection before start the testing, if improper or loose found then tighten them.
   
2. 
   Now start the testing of alternator with the help of multi meter.
   
3. 
   Attach the multi meter negative (-) or black wire to the battery negative terminal and multi meter positive (+) or red wire to the battery positive terminal, and try to avoiding touching our skin to the battery.
   
4. 
   First of all measure the voltage of the battery in vehicles off condition, if it will shows the above 12.2 Volts means battery in charged condition and able to start vehicle and also full filed the another requirements of the vehicle.
   
5. 
   If battery voltage on this stage shows below 12 or 12.2 volts that means battery was in discharged condition so do not carry the this testing further.
   
6. 
   Now start the vehicle, turn on the headlight and also accelerate the engine nearby 2000 rpm which should cause your regulator kick the alternator into high gear.
   
7. 
   After that recheck the reading on multi meter, if voltage should go to at least 13, if varying the RPMs causes the voltage to fluctuate between 13 and 14.5 volts, that means alternator in good condition and give a proper charging output for vehicle.
   
8. 
   On this time if readings are below the 13 volts that means alternator are doing undercharging and if its above 14.5 or 15 volts that means it’s doing overcharging.
   

• 
  Check the alternator gauge if the car is equipped with them. If you have a volt/amp gauge, it will read the alternator output for you. Turn on the blower fan for the AC or Heater, the headlamps, and any other accessories that put a strain on the alternator, and watch the gauge to see if it decreases voltage or amperage. As a rule, if the voltmeter is higher when the engine is running than when the engine is not, you can confidently assume that the alternator is charging.
  

FIG. 1 ALTERNATOR TESTER