Toyota Pick-ups/Land Cruiser/4Runner 1989-1996

Diagnosis and Testing

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SYSTEM TEST



  1. Disconnect a spark plug wire from a plug.
  2.  
  3. Remove the spark plug.
  4.  
  5. Reattach the spark plug to the wire.
  6.  
  7. Ground the spark plug.
  8.  


CAUTION
Do not attempt to hold the wire with your bare hand. Use as much insulation as possible between the wire and the tool holding it. Do not stand on wet concrete while testing. Do not lean on the bodywork of the car while testing. The electrical charge will pass through the easiest path to ground, make certain its not you. Make sure the metal ground point nearest the cable end is safe; don't choose components that might contain fluids or electronic components.

  1. Check to see if a bright blue spark occurs when the engine is being cranked.
  2.  

To prevent any gasoline from being injected during this test, crank the engine no more than 1-2 seconds at one time.

  1. If the spark does not occur, perform the following:
    1. Check the connection to the ignition coil and igniter, if it is bad, connect it securely. If this is OK then proceed.
    2.  
    3. Inspect the resistance of the wires, it should be 25k ohms. Replace the wires if not to specifications. If the wires are good proceed.
    4.  
    5. Check the power supply to the coil and the igniter. Turn the ignition ON . Check that there is battery voltage at the ignition coil positive terminal. If not, check the wiring between the ignition switch to the coil and igniter assemblies. If this is OK, proceed.
    6.  
    7. Check the resistance of the ignition coils, if not within specifications, replace the coil. If this is not correct replace the coil. If it is good, continue.
    8.  
    9. Check the resistance of the camshaft position sensor (refer to Driveability & Emission Controls ). If this is not correct, replace the sensor. If this is correct, proceed.
    10.  
    11. Check the resistance of the crankshaft position sensor (refer to Driveability & Emission Controls ). If this is not correct, replace the sensor. If this is correct, proceed.
    12.  
    13. If the spark is still not present, check the wiring between the ECM, distributor and igniter. If the wiring is OK, replace the igniter.
    14.  

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