Engine Adjustment: Adjustment
- INSPECT COOLANT, see ON-VEHICLE INSPECTION .
- INSPECT ENGINE OIL, see ON-VEHICLE INSPECTION .
- INSPECT BATTERY SPECIFIC GRAVITY, see ON-VEHICLE INSPECTION .
- INSPECT AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
- INSPECT FAN AND GENERATOR V BELT NOTE: Use of the automatic tensioner has made the tension and flexibility measurements unnecessary.
- Check that the indicator mark on the automatic tensioner is within the A range as shown in the illustration.
- When the mark is out of the standard range, exchange the V belt with new one.
- INSPECT V-RIBBED BELT TENSIONER ASSEMBLY, see MANUFACTURER'S SUGGESTED SCHEDULED MAINTENANCE .
- WARM UP ENGINE
- INSPECT IGNITION TIMING
- When using LEXUS hand-held tester:
- Connect a LEXUS hand-held tester to the DLC3.
- Please refer to the LEXUS hand-held tester operator's manual for further details.
- Start the engine at idle.
- Using a timing light, check the ignition timing.
Ignition timing: 8 - 12° BTDC @ idle
(Transmission in neutral position)
- Disconnect the LEXUS hand-held tester from the DLC3.
- When not using LEXUS hand-held tester:
- Using SST, connect tachometer probe to terminal TAC of the DLC3.
SST 09843-18030
- Connect the tester probe of a timing light to the yellow lead wire of the ignition coil connector for No. 1 cylinder.
- Using SST, connect terminals TC and CG of the DLC3.
SST 09843-18040
- Using a timing light, check the ignition timing.
Ignition timing: 8 - 12° BTDC @ idle
(Transmission in neutral position)
- Remove the SST from the DLC3.
- Disconnect the timing light from the engine.
- Disconnect the tachometer from the DLC3.
- Using SST, connect tachometer probe to terminal TAC of the DLC3.
- When using LEXUS hand-held tester:
- INSPECT ENGINE IDLE SPEED
- When using LEXUS hand-held tester:
- Connect a LEXUS hand-held tester to the DLC3.
- Please refer to the LEXUS hand-held tester operator's manual for further details.
- Race the engine at 2,500 RPM for approx. 90 seconds.
- Check the idle speed.
Idle speed (w/Cooling fan OFF): 750 +/- 50 RPM
- Disconnect the LEXUS hand-held tester from the DLC3.
- When not using LEXUS hand-held tester:
- Using SST, connect tachometer probe to terminal TAC of the DLC3.
SST 09843-18030
- Please refer to the LEXUS hand-held tester operator's manual for further details.
- Race the engine at 2,500 RPM for approx. 90 seconds.
- Check the idle speed.
Idle speed (w/Cooling fan OFF): 750 +/- 50 RPM
- Remove the SST from the DLC3.
- Disconnect the tachometer from the DLC3.
- Using SST, connect tachometer probe to terminal TAC of the DLC3.
- When using LEXUS hand-held tester:
- INSPECT COMPRESSION
- Remove the V-bank cover.
- Remove the air cleaner inlet and intake air pipe.
- Disconnect the throttle control motor connector.
- Remove the oil level gauge guide.
- Remove the 8 ignition coils.
- Remove the 8 spark plugs. I
- Disconnect the 8 injector connectors.
- Inspect the cylinder compression pressure.
- Insert a compression gauge into the spark plug hole.
- Fully open the throttle forcibly by hand.
- While cranking the engine, measure the compression pressure.
NOTE: Always use a fully charged battery to obtain engine speed of 250 RPM or more.
- Repeat steps (1) through (3) for each cylinder.NOTE: This measurement must be done in as short a time as possible.
Compression pressure:
1,226 kPa (12.5 kgf/cm 2 , 178 psi) or more
Minimum pressure: 981 kPa (10.0 kgf/cm 2 , 142 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm 2 , 14 psi) or less
- If the cylinder compression in one or more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps (a) through (c) for cylinders with low compression.
- If adding oil helps 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 sticking or seating is improper, or there may be leakage past the gasket.
- Connect the 8 injector connectors.
- Install the 8 spark plugs.
- Install the 8 ignition coils.
- Install the oil level gauge guide.
- Connect the throttle control motor connector.
- Install the air cleaner inlet and intake air pipe.
- Install the V-bank cover.
- INSPECT CO/HC
HINT:
This check is used only to determine whether or not the idle CO/HC complies with regulations.
- Start engine.
- Hold the engine at 2,500 RPM for approx. 180 seconds
- Insert CO/HC meter testing probe at least 40 cm (1.3 ft) into tailpipe during idling.
- Immediately check CO/HC concentration at idle and/or 2,500 RPM.NOTE:
- Complete the measuring within 3 minutes.
- When performing the 2 mode (2,500 RPM and idle) test, follow the measurement order prescribed by the applicable local regulations.
If the CO/HC concentration does not comply with regulations, troubleshoot in the order given below.
- Check the heated oxygen sensor operation, see DTC P0135, DTC P0141, DTC P0155 OR DTC P0161 and DTC P0136 OR DTC P0156: HEATED OXYGEN SENSOR .
- See the PROBLEM SYMPTOMS (CO/HC) table.
PROBLEM SYMPTOMS (CO/HC)CO HC Symptom Causes Normal High Rough idle - Faulty ignitions:
- Incorrect timing
- Fouled, shorted or improperly gapped plugs
- Incorrect valve clearance
- Leaky intake and exhaust valves
- Leaky cylinder
Low High Rough idle (HC reading fluctuating) - Vacuum leaks:
- PCV hose
- Intake manifold
- Throttle body
- Lean mixture causing misfire
High High Rough idle (Black smoke from exhaust) - Restricted air filter
- Faulty SFI system:
- Faulty pressure regulator
- Defective ECT sensor
- Faulty ECM
- Faulty injector
- Faulty throttle position sensor
- MAF sensor
- DRIVING TEST