Toyota Tundra Service Manual: On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. PERFORM SPARK TEST

(a) Check for DTCs (See page ).

NOTICE:

If any DTC is present, perform troubleshooting procedures for that DTC.

(b) Check if sparks occur.

(1) Remove the ignition coils and spark plugs (See page ).

(2) Install the spark plug to the ignition coil and connect the ignition coil connector.

(3) Disconnect the 8 injector connectors.

(4) Ground the spark plug.

(5) Visually check that sparks occur while the engine is being cranked.

NOTICE:

• When performing the inspection, be sure to ground the hexagonal portion or the threaded portion of the spark plug.
• Do not crank the engine for more than 2 seconds.

  For vehicles with a cranking hold function, turn the ignition switch off during cranking to stop cranking.

• If an ignition coil assembly is struck or dropped, replace it with a new one.
• If a spark plug is struck or dropped, replace it with a new one.

2. INSPECT IGNITION COIL AND SPARK PLUG

(a) Spark test flowchart.

(1) Check that the wire harness side connector of the ignition coil with igniter is securely connected.

(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.

(3) Check the power supply to the ignition coil with igniter.

1. Turn the ignition switch to ON.
2. Check that there is battery voltage at the ignition coil positive (+) terminal.

(4) Inspect the spark plug.

1. Replace the spark plug with a normal one.
2. Perform a spark test.

NOTICE:

• If an ignition coil assembly is struck or dropped, replace it with a new one.
• If a spark plug is struck or dropped, replace it with a new one.

(5) Connect the 8 injector connectors.

(6) Install the ignition coils and spark plugs (See page ).

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.

(1) Using a megohmmeter, measure the insulation resistance. Standard Insulation Resistance: Tester Connection Condition Specified Condition Spark plug (terminal part) - Body ground Always 10 MΩ or higher If the insulation resistance is below the specified range, replace the spark plug. HINT: If a megohmmeter is not available, perform the following simple inspection instead.

(b) Alternative inspection method:

(1) Start the engine.*

(2) Quickly accelerate the engine to 4000 rpm 5 times.*

NOTICE:

*: Do not perform this step if P0300 (misfire detection) or a related DTC is stored.

(3) Remove the spark plug.

(4) 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 threads and insulator.

If there is any damage, replace the spark plug.

Recommended Spark Plug:

(d) Check the spark plug electrode gap.

Maximum electrode gap for a used spark plug:

1.3 mm (0.0512 in.)

If the gap is more 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:

If adjusting the gap of a new spark plug, bend only the base of the ground electrode. Do not touch the tip. Never attempt to adjust the gap of a used plug.

If the electrode has traces of wet carbon, allow it to dry and then clean it with a spark plug cleaner.

Standard air pressure:

588 kPa (6.0 kgf/cm2, 85 psi)

Standard duration:

20 seconds or less

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.