Last Modified: 11-29-2007 1.6 G
Service Category: Engine/Hybrid System Section: Engine Mechanical
Model Year: 2008 Model: Sequoia Doc ID: RM000002BO100FX
Title: 2UZ-FE ENGINE MECHANICAL: ENGINE: ON-VEHICLE INSPECTION (2008 Sequoia)

ON-VEHICLE INSPECTION

1. INSPECT ENGINE COOLANT

2UZ-FE COOLING: COOLING SYSTEM: ON-VEHICLE INSPECTION (2008 Sequoia)

2. INSPECT ENGINE OIL

2UZ-FE LUBRICATION: LUBRICATION SYSTEM: ON-VEHICLE INSPECTION (2008 Sequoia)

3. INSPECT BATTERY 2UZ-FE BATTERY / CHARGING: CHARGING SYSTEM: ON-VEHICLE INSPECTION (2008 Sequoia)+

4. INSPECT AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

(a) Visually check that the air filter is not excessively damaged or oily. If necessary, replace the air filter.

5. INSPECT V-RIBBED BELT TENSIONER ASSEMBLY 2UZ-FE ENGINE MECHANICAL: DRIVE BELT: ON-VEHICLE INSPECTION (2008 Sequoia)+

6. INSPECT FAN AND GENERATOR V BELT 2UZ-FE ENGINE MECHANICAL: DRIVE BELT: ON-VEHICLE INSPECTION (2008 Sequoia)+

7. INSPECT IGNITION TIMING

(a) Warm up and stop the engine.

(1) Allow the engine to warm up to a normal operating temperature.

(b) When using the Techstream:

(1) Connect the Techstream to the DLC3.

(2) Start the engine and idle it.

(3) Push the Techstream main switch ON.

(4) Enter the following menus: Powertrain / Engine / Data List / IGN Advance.

Standard ignition timing:

5 to 15° BTDC at idling (transmission in neutral position and A/C switch OFF)

HINT:

Refer to the Techstream operator's manual for further details.

(5) Disconnect the Techstream from the DLC3.


(c) When not using the Techstream:

(1) Connect the tester probe of a timing light to the wire of the ignition coil connector for the No. 1 cylinder.

NOTICE:

Use a timing light that detects primary signals.

(2) Using SST, connect terminals 13 (TC) and 4 (CG) of the DLC3.

SST: 09843-18040

NOTICE:

Confirm the terminal numbers before connecting them. Connecting the wrong terminals can damage the engine.

(3) Using the timing light, check the ignition timing.

Ignition timing:

5 to 15° BTDC at idling (transmission position)

(4) Remove SST from the DLC3.

(5) Disconnect the timing light from the engine.

8. INSPECT ENGINE IDLE SPEED

(a) Warm up and stop the engine.

(1) Allow the engine to warm up to a normal operating temperature.

(b) When using the Techstream:

(1) Connect the Techstream to the DLC3.

NOTICE:

Switch off all accessories and the A/C before connecting the Techstream.

(2) Race the engine at 2500 rpm for approximately 90 seconds.

(3) Push the Techstream main switch ON.

(4) Enter the following menus: / Engine / Data List / Engine Speed.

Standard idle speed:

650 to 750 rpm (transmission in neutral and A/C switch OFF)

HINT:

Refer to the Techstream operator's manual for further details.

If the idle speed is not as specified, check the air intake system.

(5) Disconnect the Techstream from the DLC3.


(c) When not using the Techstream:

(1) Using SST, connect the tachometer probe to terminal 9 (TAC) of the DLC3.

SST: 09843-18030

NOTICE:

Confirm the terminal numbers before connecting them. Connecting the wrong terminals can damage the engine.

(2) Race the engine at 2500 rpm for approximately 90 seconds.

(3) Check the idle speed.

Idle speed:

650 to 750 rpm (transmission in neutral and A/C switch OFF)

If the idle speed is not as specified, check the air intake system.

(4) Disconnect the tachometer from the DLC3.

9. INSPECT COMPRESSION

(a) Warm up and stop the engine.

(1) Allow the engine to warm up to a normal operating temperature.

(b) Remove the 2 nuts and throttle body cover.

(c) Remove the air cleaner hose assembly.

(d) Remove the air cleaner cap.

(e) Disconnect the 8 injector connectors and 8 ignition coils.

(f) Remove the 8 bolts and 8 ignition coils.

(g) Remove the 8 spark plugs.


(h) Check the cylinder compression pressure.

NOTICE:

Check each cylinder's compression pressure in the same way.

(1) Insert a compression gauge into the spark plug hole.

(2) Fully open the throttle.

(3) While cranking the engine, measure the compression pressure.

Standard compression pressure:

1373 kPa (14.0 kgf/cm2, 199 psi) or more

Minimum pressure:

1030 kPa (10.5 kgf/cm2, 149 psi)

Difference between each cylinder:

98 kPa (1.0 kgf/cm2, 14.2 psi) or less

NOTICE:

  • Always use a fully charged battery to obtain an engine speed of 250 rpm or more.
  • This measurement must be done as quickly as possible.

(4) If the cylinder compression is low in one or more cylinders, pour a small amount of engine oil into the cylinder with low compression through its spark plug hole. Then inspect the cylinder compression pressure again.

HINT:

  • If adding oil helps boost the compression, it is likely that the piston rings and/or cylinder bore are worn or damaged.
  • If pressure stays low, a valve may be stuck or seated improperly, or there may be leakage in the gasket.

(i) Install the 8 spark plugs.

(j) Install the 8 ignition coils with the 8 bolts.

(k) Connect the 8 injector connectors and 8 ignition coils.

(l) Install the air cleaner cap.

(m) Install the air cleaner hose.

(n) Install the throttle body cover with the 2 nuts.

10. INSPECT CO/HC

HINT:

This check is used only to determine whether or not the idle CO/ HC complies with regulations.

(a) Start the engine.

(b) Keep the engine speed at 2500 rpm for approximately 180 seconds.


(c) Insert the CO/HC meter testing probe at least 40 cm (1.31 ft.) into the tailpipe during idling.

(d) Immediately check CO/HC concentration at idle and/or 2500 rpm.

HINT:

When performing the 2 mode (2500 rpm and idle) test, follow the measurement order prescribed by the applicable local regulations.

(e) If the CO/HC concentration does not comply with regulations, troubleshoot in the order given below.

(1) Check the A/F sensor and heated oxygen sensor operation.

(2) See the table below for possible causes, and then inspect and correct the applicable causes if necessary.

CO

HC

Symptom

Cause

Normal

High

Rough idle

  1. Faulty ignitions:
    • Incorrect timing
    • Plugs (contaminated, shorted or gaps are defective)
  2. Incorrect valve clearance
  3. Leaky intake and exhaust valves
  4. Leaky cylinder

Low

High

Rough idle

(Fluctuating HC reading)

  1. Vacuum leaks:
    • PCV hose
    • Intake manifold
    • Throttle body
    • Brake booster line
  2. Lean mixture causing misfire

High

High

Rough idle

(Black smoke from exhaust)

  1. Restricted air filter
  2. Faulty SFI system:
    • Faulty pressure regulator
    • Defective ECT sensor
    • Faulty ECM
    • Faulty injectors
    • Faulty throttle position sensor
    • Faulty MAF meter