Mechanical

CO/HC EM-1

COMPRESSION EM-3

VALVE CLEARANCE EM-4

IGNITION TIMING EM-13

IDLE SPEED EM-14

TIMING CHAIN EM-15

CYLINDER HEAD EM-36

ENGINE UNIT EM-70

CYLINDER BLOCK EM-85

EXHAUST SYSTEM EM-115

CO/HC

INSPECTION

HINT:

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

1. INSTALL CONDITIONS

(a) Engine at normal operating temperature

(b) Air cleaner installed

(c) Air pipes and hoses of air induction system connected

(d) Ail accessories switched OFF

(e) Ail vacuum lines properly connected

(f) SFI system wiring connectors fully plugged (g} Ignition timing check correctly

(h) Transmission in neutral position

(i) Tachometer and CO/HC meter calibrated by hand

2. START ENGINE

3. RACE ENGINE AT 2,500 RPM FOR APPROX. 180 SECONDS

4. INSERT CO/HC METER TESTING PROBE AT LEAST 40 cm (1.3 ft) INTO TAILPIPE DURING IDLING

5. IMMEDIATELY CHECK CO/HC CONCENTRATION AT IDLE AND/OR 2,500 RPM

Complete the measuring with 3 minutes. HINT:

When doing the 2 mode (idle and 2,500 rpm) test, these 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 heated oxygen sensor operation (See page Dt-49).

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

CO

HC

Problems

Causes

Normal

High

• Incorrect timing

♦ Fouled, shorted or improperly gapped plugs

* Open or crossed high-tension cords

2. Incorrect valve clearance

3. Leaky intake and exhaust valves

4. Leaky cylinders

Low

(Fluctuating HC reading)

1. Vacuum leaks:

• Intake manifold •Throttle body

• Brake booster line

2. Lean mixture causing misfire

High

(Slack smoke from exhaust)

1. Restricted air filter

2. Plugged PCV valve

3. Faulty SFI systems:

• Faulty pressure regulator

• Defective ECT sensor •Defective (AT sensor -Faulty ECM

• Faulty injectors

• Faulty throttle posilion sensor

ENGINE MECHANICAL

COMPRESSION

COMPRESSION INSPECTION

HINT:

If there is lack of power, excessive oil consumption or poor fuel economy, measure {he compression pressure.

1. WARM UP AND STOP ENGINE

Allow the engine to warm up to normal operating temperature.

2. REMOVE IGNITION COIL (See page IG-6)

3. REMOVE SPARK PLUGS

4. INSPECT CYLINDER COMPRESSION PRESSURE

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

(b) Fully open the throttie.

(c) Whiie cranking the engine, measure the compression i pressure. I

HINT:

Always use a fully charged battery to obtain engine speed of 250 rpm or more.

(d) Repeat steps (a) through (c) for each cylinder. NOTICE:

This measurement must be done in as short a time as possible.

Compression pressure: 1ZZ-FE 1,500 kPa (15.3 kgf/cm2, 218 psi) 2ZZ-GE 1,400 kPa (14.3 kgf/cm2, 203 psi) or more Minimum pressure:

1ZZ-FE 1,000 kPa (10.2 kgf/cm2,145 psi) 2ZZ-GE 1,000 kPa (10.2 kgf/cm2,145 psi) Difference between each cylinder: 1ZZ-FE 100 kPa (1.0 kgf/cm2,15 psi) or less 2ZZ-GE 110 kPa (1.1 kgf/cm2,16 psi) or less

(e) If the cylinder compression in one more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hoie and repeat steps (a) through (c) for cylinders with Sow 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.

5. REINSTALL SPARK PLUGS

6. INSTALL IGNITION COIL (See page IG-7)

VALVE CLEARANCE

ADJUSTMENT

HINT:

Inspect and adjust the valve clearance when the engine is cold. 1. REMOVE CYLINDER HEAD COVER (See page EM-18)

Toyota Diesel Timing Marks

2. SET NO. 1 CYLINDER TO TDC/COMPRESSION

(a) Turn the crankshaft pulley, and align its groove with the timing mark ,:0" of the timing chain cover.

Toyota Timing Marks

(b) Check that the point marks of the camshaft timing sprockets are in straight line on the timing chain cover surface as shown in the illustration. If not, turn the crankshaft 1 revolution (360°) and align the marks as above.

Valve Clearance

3. INSPECT VALVE CLEARANCE

(a) Check only the valves indicated.

Using a feeler gauge, measure the clearance between the valve lifter and camshaft. Record the out-of-specification valve clearance measurements. They wilt be used later to determine the required replacement adjusting shim. Valve clearance (Cold): 1ZZ-FE:

Intake 0.15 - 0.25 mm (0.006 - 0.010 in.) Exhaust 0.25 - 0.35 mm (0.010 - 0.014 in.) 2ZZ-GE:

Intake 0.15 - 0.25 mm (0.006 - 0.010 in.) Exhaust 0.35 - 0.45 mm (0.014 - 0.018 in.)

1ZZ-FE:

Pti8

Was this article helpful?

0 0
Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

Get My Free Ebook


Post a comment