IGNITION COIL (WITH BUILT-IN POWER TRANSISTOR) CHECK <134, 135, 4G1>


Check by the following procedure, and replace if there is a malfunction.

PRIMARY COIL AND POWER TRANSISTOR CONTINUITY CHECK

note
  • An analogue-type circuit tester should be used.
  • Connect the negative (-) prove of the circuit tester to terminal No. 1.
caution
    This test must be performed quickly (in less than 10 seconds) to prevent coil from burning and power transistor from breakage.
Connect and disconnect 4.5 - 9.0 V battery between terminal No. 2 and No. 3, and observe the ohmmeter whether there is continuity or not.
4.5 - 9 V power supply between 2 - 3
 Continuity between 1 - 2
When current is flowing
 Continuity
When current is not flowing
 No continuity

SECONDARY COIL CHECK
note It is impossible to check the secondary coil through the continuity check as a diode is integrated in the secondary coil circuit of this ignition coil. Accordingly, check the secondary coil in the following procedure.
1.Disconnect the ignition coil connector.
2.Remove the ignition coil and install a new spark plug to the ignition coil.
3.Connect the ignition coil connector.
4.Earth the side electrode of the spark plug and crank the engine.
5.Check that spark is produced between the electrodes of the spark plug.
6.If no spark plug is produced, replace the ignition coil with a new one and recheck.
7.If spark is produced with the new ignition coil, replace the old one as it is faulty. If no spark is produced again, the ignition circuit is suspected as faulty. Check the ignition circuit.