Ignition System: Testing and Inspection
1NR-FE ENGINE CONTROL: IGNITION SYSTEM: ON-VEHICLE INSPECTION
1. INSPECT PERFORM SPARK TEST
(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.
NOTICE:
If any DTC is present, perform troubleshooting in accordance with the procedure for that DTC.
(b) Remove the 4 ignition coils and 4 spark plugs Removal.
(c) Disengage the clamp and disconnect the wire harness from the cylinder head cover sub-assembly.
(d) Disconnect the 4 injector connectors.
(e) Install a spark plug to each ignition coil and connect the ignition coil connector.
(f) Ground the spark plug.
(g) Check that spark occurs while the engine is being cranked.
(h) Check whether sparks occur.
NOTICE:
* Install and test each spark plug and ignition coil individually, disconnecting the ignition coil and removing the spark plug when each test is complete.
* Ground the spark plugs when checking them.
* Do not crank the engine for more than 2 seconds.
* For vehicles with the cranking holding control system, cranking will not stop unless the ignition switch is turned to OFF.
* Do not use a ignition coil and spark plug that has been dropped or subjected to a strong impact.
(i) If spark does not occur, perform the following procedure.
2. REMOVE IGNITION COIL AND SPARK TEST
(a) Perform the spark test in accordance with the following procedure.
(1) Check that the wire harness side connector of the ignition coil with igniter is securely connected.
Result
(2) Perform a spark test on each ignition coil with igniter.
1 If there is a cylinder where sparks do not occur, replace its ignition coil with the ignition coil of a cylinder where sparks occur normally.
2 Crank the engine and visually check that sparks occur at the cylinder with the normally operating ignition coil.
Result
(3) Perform a spark test on each spark plug.
1 If there is a cylinder where sparks do not occur, replace its spark plug with the spark plug of a cylinder where sparks occur normally.
2 Crank the engine and visually check that sparks occur at the cylinder with the normally operating spark plug.
Result
(b) Connect the 4 injector connectors.
(c) Engage the clamp and connect the wire harness to the cylinder head cover sub-assembly.
(d) Install the 4 ignition coils and 4 spark plugs Installation.
(e) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(f) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.
3. INSPECT SPARK PLUG
NOTICE:
* Do not use a wire brush for cleaning.
* Do not attempt to adjust the electrode gap of a used spark plug.
(a) Check the electrode using a megohmmeter:
(1) Using a megohmmeter, measure the insulation resistance.
Text in Illustration
Standard Insulation Resistance:
HINT
* If the result is not as specified, clean the spark plug with a spark plug cleaner and measure the resistance again.
* If a megohmmeter is not available, perform the following simple inspection instead.
(b) Alternative inspection method:
(1) Quickly accelerate the engine to 4000 rpm 5 times.
(2) Remove the spark plug.
(3) Visually check the spark plug.
If the electrode is dry, the spark plug is functioning properly. If the electrode is damp, proceed to the next step.
(c) Check the spark plug for any damage to its thread and insulator.
If there is any damage, replace the spark plug.
Recommended Spark Plug:
(d) Reference:
(1) Check the spark plug electrode gap.
Text in Illustration
Maximum Electrode Gap for a Used Spark Plug:
1.3 mm (0.0512 in.)
If the gap is greater than the maximum, replace the spark plug.
Electrode Gap for a New Spark Plug:
1.0 to 1.1 mm (0.0394 to 0.0433 in.)
NOTICE:
Never attempt to adjust the gap of a used plug.
(e) Clean the spark plug.
If the electrode has traces of wet carbon, clean the electrode with a spark plug cleaner and then dry with compressed air.
Standard:
HINT
Only use the spark plug cleaner when the electrode is free of oil. If the electrode has traces of oil, use gasoline to clean off the oil before using the spark plug cleaner.