Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM0000013K8009X
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: 2UZ-FE ENGINE MECHANICAL: ENGINE: ON-VEHICLE INSPECTION; 2007 MY LX470 [08/2006 -        ]

ON-VEHICLE INSPECTION

1. CHECK IGNITION TIMING

(a) When using the intelligent tester:

(1) Connect the intelligent tester to the DLC3.

HINT:

Refer to the intelligent tester operator's manual for further details.

Standard ignition timing:

5 to 15° BTDC @ idle (Shift lever on N)

(2) Disconnect the intelligent tester from the DLC3.

(b) When not using the intelligent tester:

(1) Remove the V-bank cover.

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

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

SST: 09843-18030

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

SST: 09843-18040

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

Standard ignition timing:

5 to 15° BTDC @ idle (Shift lever on N)

(6) Remove the SST from the DLC3.

(7) Disconnect the timing light from the engine.

(8) Install the V-bank cover.

2. CHECK ENGINE IDLE SPEED

(a) When using the intelligent tester:

(1) Connect the intelligent tester to the DLC3.

HINT:

Refer to the intelligent tester operator's manual for further details.

(2) Maintain the engine at 2,500 rpm for approximately 90 seconds.

(3) Check the idle speed.

Standard idle speed:

700 +- 50 rpm

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

(4) Disconnect the intelligent tester from the DLC3.

(b) When not using the intelligent tester:

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

SST: 09843-18030

HINT:

Refer to the intelligent tester operator's manual for further details.

(2) Maintain the engine at 2,500 rpm for approximately 90 seconds.

(3) Check the idle speed.

Standard idle speed:

700 +- 50 rpm

(4) Remove the SST from the DLC3.

(5) Disconnect the tachometer from the DLC3.

3. CHECK COMPRESSION

(a) Remove the V-bank cover.

(b) Remove the air cleaner hose assembly.

(c) Disconnect the throttle position sensor and control motor connector.

(d) Remove the oil dipstick guide.

(e) Remove the 8 ignition coils.

(f) Remove the 8 spark plugs.

(g) Disconnect the 8 injector connectors.

(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:

1,373 kPa (14.0 kgf/cm 2 , 199 psi) or more

Minimum pressure:

1,030 kPa (10.5 kgf/cm 2 , 149 psi)

Difference between each cylinder:

98 kPa (1.0 kgf/cm 2 , 14 psi)

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.

If the cylinder compression is low, pour a small amount of engine oil into the cylinder through the spark plug hole and inspect again.

HINT:

If adding oil increases the compression, the piston rings and/or cylinder bore may be worn or damaged.

If pressure stays low, a valve may be stuck or seated improperly, or there may be leakage in the gasket.

(i) Connect the 8 injector connectors.

(j) Install the 8 spark plugs.

(k) Install the 8 ignition coils.

(l) Install the oil dipstick guide.

(m) Connect the throttle position sensor and control motor connector.

(n) Install the air cleaner hose assembly.

(o) Install the V-bank cover.

4. CHECK 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) Maintain the engine at 2,500 rpm for approximately 180 seconds.

(c) Insert a CO/HC meter testing probe at least 40 cm (1.3 ft.) into the tailpipe during idling.

(d) Check CO/HC concentration at idle and/or 2,500 rpm.

HINT:

  • Complete the measurement within 3 minutes.
  • Check regulations in your area when performing 2 mode CO/HC concentration testing (engine check at both idle speed and at 2,500 rpm).

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

(1) Check the heated oxygen sensor operation 2007 MY LX470 [08/2006 -        ]; 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0136-P0138,P0156-P0158; Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2) .

(2) See the table below for possible causes, and then inspect and repair.

CO

HC

Symptom

Causes

Normal

High

Rough idle

1. Faulty ignitions:

  • Incorrect timing
  • Fouled, shorted or improperly gapped plugs

2. Incorrect valve clearance

3. Leaky intake and exhaust valves

4. Leaky cylinder

Low

High

Rough idle

(Fluctuating HC reading)

1. Vacuum leaks:

  • Ventilation hose
  • Intake manifold
  • Throttle body

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 injector
  • Faulty throttle position sensor
  • MAF sensor