How to Check a good Ignition Coil

Description:
Ignition timing is controlled by the electronic control ignition timing system.The standard reference ignition timing data for the engine operating conditions are preprogrammed in the memory of the ECM (Engine Control Module).
The engine operating condition, are detected by the various sensor.Based on  this sensor signals and ignition timing data,signal to interrupt the primary current are sent to the ECM. the ignition coil is activated, and timing is controlled.
On Vehicle Inspection = Spark Test

1. Remove the Ignition coil connector.
2. Remove the ignition coil.
3. Using a spark plug socket, remove the spark plug.
4. Install the sparkplug to the ignition coil.
5. Ground the spark plug to the engine.
6. Check is spark occurs while engine is being cracked.
   
   Note:
   Before Cracked the engine it is necessary to remove the fuel pump relay from the fuse box. And the engine will crack within 5-10 seconds only.
7. Inspect the spark plugs.
8. Using the sparkplug socket install the sparkplug.
9. Install the ignition coil.
10. Reconnect the ignition coil connector.
    Spark Test

Spark test
Check the connection of ignition coil connector --–Bad---> Connect securely.
                    
                    OK

Check the ignition -----------------------------------Bad----->Replace the ignition coil.

                    OK

Check the power supply of ignition coil
1) Turn ignition switch on.                  ------------Bad------> Check wiring between ignition switch
                                                                                   and ignition coil
2) Check that there is battery voltage
    at ignition coil positive terminal.

                    OK

Check the camshaft position sensor-------------Bad-------> Replace camshaft position sensor.
                   OK
Check the crankshaft position sensor-----------Bad------> Replace crankshaft position sensor.
                  OK
Check ignition signal from ECM-----------------Bad------> Check wiring between ECM and ignition coil
                                                                             and then try another ECM.
                 OK
Try another ignition coil.

Inspect the Spark plug
1) Remove the ignition coil connector.
2) Remove the ignition coil.
3) Using a spark plug socket, remove the spark plug.
4) Inspect the electrodes and ceramic insulator.

Condition	Dark deposits	White deposits
Description	Fuel mixture too rich -low air intake	-fuel mixture too lean -Advanced ignition timing -Insufficient plug tightening torque

5)Check the electrodes gap.
  
  Standard
Unleaded: 1.0~ 1.1 mm(0.0394~0.0433 in)
Leaded   : 0.8~ 0.9mm(0.0315~0.0354 in)
Inspect the Ignition Coil

1) Measure the primary coil resistance between terminals(+) and (-)
    = Standard value- 0.62 ohms + or – 10%