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EC0H3−02
−
EMISSION CONTROL THREE−WAY CATALYTIC CONVERTER (TWC)
SYSTEMEC−15
628
Author: Date:
1996 LAND CRUISER (RM451U)
THREE−WAY CATALYTIC CONVERTER (TWC) SYSTEM
INSPECTION
1. EXHAUST PIPE ASSEMBLY INSPECTION
(a) Check connection for looseness or damage
(b) Check clamps for weakness, cracks or damage
2. TWC INSPECTION
Check for dents or damage
If any part of the protector is damaged or dented to the extent that it touches the TWC, repair or replace it.
3. HEAT INSULATOR INSPECTION
(a) Check heat insulator for damage
(b) Check for adequate clearance between TWC and heat insulator.
4. FRONT TWC AND REAR TWC REPLACEMENT (See page EM−11 0 )
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EM1E0−04
−
ENGINE MECHANICAL CO/HC
EM−1
504
Author: Date:
1996 LAND CRUISER (RM451U)
CO/HC
INSPECTION
HINT:
This check is used only to det ermine whether or not the idle CO/
HC complies with regulations.
1. INITIAL CONDITIONS
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected
(d) All accessories switched OFF
(e) All vacuum lines properly connected
HINT:
All vacuum hoses for EGR systems, etc. should be properly
connected.
(f) SFI system wiring connectors fully plugged
(g) Ignition timing set 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 SE-
CONDS
4. 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
HINT:
When doing the 2 mode (2,500 rpm and idle) test, follow the
measurement order prescribed by the applicable local regula-
tions.
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EM−2
−
ENGINE MECHANICAL CO/HC
505
Author: Date:
1996 LAND CRUISER (RM451U)
6. TROUBLESHOOTING
If the CO/HC concentration does not comply with regulations,
troubleshoot in the order given below.
See the table below for possible causes, and then inspect and
correct the applicable causes if necessary.
COHCProblemsCauses
NormalHighRough idle
3. Faulty ignitions:
Incorrect timing
Fouled, shorted or improperly gapped plugs
Open or crossed high −tension cords
Cracked distributor cap
4. Incorrect valve clearance
5. Leaky EGR valve
6. Leaky intake and exhaust valves
7. Leaky cylinders
LowHighRough idle
(Fluctuating HC reading)
1. Vacuum leaks:
PCV hose
EGR valve
Intake manifold
Air intake chamber
Throttle body
IAC valve
Brake booster line
2. Lean mixture causing misfire
HighHighRough idle
(Black smoke from exhaust)
1. Restricted air filter
2. Faulty SFI systems:
Faulty pressure regulator
Clogged fuel return line
Defective ECT sensor
Faulty ECM
Faulty injector
Faulty throttle position sensor
Faulty MAF meter
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EM0KR−04
−
ENGINE MECHANICAL COMPRESSION
EM−3
506
Author: Date:
1996 LAND CRUISER (RM451U)
COMPRESSION
INSPECTION
HINT:
If there is lack of power, excessive oil consumption or poor fuel
economy, measure the compression pressure.
1. WARM UP AND STOP ENGINE
Allow the engine to warm up to normal operating temperature.
2. DISCONNECT DISTRIBUTOR CONNECTOR
3. REMOVE SPARK PLUGS (See page IG−1 )
4. CHECK CYLINDER COMPRESSION PRESSURE
(a) Insert a compression gauge into the spark plug hole.
(b) Fully open the throttle.
(c) While cranking the engine, measure the compression pressure.
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 pos-
sible. Compression pressure:
1,176 kPa (12.0 kgf/cm
2, 171 psi) or more
Minimum pressure: 883 kPa (9.0 kgf/cm
2, 128 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.
5. REINSTALL SPARK PLUGS (See page IG−1 )
6. RECONNECT DISTRIBUTOR CONNECTOR
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EM1Q4−01
P05120A16078
1 Dot Mark
EM−4
−
ENGINE MECHANICAL VALVE CLEARANCE
507
Author: Date:
1996 LAND CRUISER (RM451U)
VALVE CLEARANCE
INSPECTION
HINT:
Inspect and adjust the valve clearance when the engine is cold.
1. DRAIN ENGINE COOLANT
2. REMOVE THROTTLE BODY (See page SF−45)
3. DISCONNECT ENGINE WIRE AND HEATER VALVE FROM COWL PANEL
(a) Remove the 2 bolts and disc onnect the ground strap and
engine wire.
(b) Remove the 2 bolts and disconnect the heater valve.
4. DISCONNECT HIGH −TENSION CORDS FROM SPARK
PLUGS (See page IG−1 )
5. REMOVE CYLINDER HEAD COVER
Remove the 13 bolts, cylinder head cover and gasket.
6. 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.
(b) Check that the timing marks (1 and 2 dots) of the camshaft
drive and driven gears are in straight line on the cylinder
head surface as shown in the illustration.If not, turn the
crankshaft 1 revolution (360 °) and align the marks as
above.
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−
ENGINE MECHANICAL VALVE CLEARANCE
EM−5
508
Author: Date:
1996 LAND CRUISER (RM451U)
7. INSPECT VALVE CLEARANCE
(a) Check only the valves indicated.
Using a thickness gauge, measure the clearance
between the valve lifter and camshaft.
Record the out−of−specification valve clearance
measurements. They will be used later to determine
the required replacement adjusting shim.
Valve clearance (Cold):
Intake0.15 − 0.25 mm (0.006 − 0.010 in.)
Exhaust0.25 − 0.35 mm (0.010 − 0.041 in.)
(b) Turn the crankshaft pulley 1 revolution (360 °) and align
the its groove with timing mark ”0” of the timing chain cov-
er.
(c) Check only the valves indicated as shown. Measure the valve clearance (See procedure in step (a) above).
8. Except for rear valves of No. 6 cylinder ADJUST VALVE CLEARANCE
(a) Remove the adjusting shim.
Turn the crankshaft to position the cam lobe of the
camshaft on the adjusting valve upward.
Position the notch of the valve lifter toward the spark
plug side.
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EM0494
EM−6
−
ENGINE MECHANICAL VALVE CLEARANCE
509
Author: Date:
1996 LAND CRUISER (RM451U)
Using SST (A), press down the valve lifter and place
SST (B) between the camshaft and valve lifter
flange. Remove SST (A).
SST 09248−06020, 09248 −55050 (09248−05510)
HINT:
Apply SST (B) at slight angle on the side marked with ”11”,
at the position shown in the illustration.
When SST (B) is inserted too deeply, it will get pinched by
the shim. To prevent it from being stuck, insert it shallowly
from the outside of the cylinder head, at a slight angle.
Remove the adjusting shim with a small screwdriver and
magnetic finger.
(b) Determine the replacement adjusting shim size by follow- ing the Formula or Charts:
Using a micrometer, measure the thickness of the
removed shim.
Calculate the thickness of a new shim so that the
valve clearance comes within specified value.
T ....... Thickness of removed shim
A ....... Measured valve clearance
N ....... Thickness of new shim
Intake: N = T + (A − 0.20 mm (0.008 in.))
Exhaust: N = T + (A − 0.30 mm (0.012 in.))
Select a new shim with a thickness as close as pos-
sible to the calculated value.
HINT:
Shims are available in 17 sized in increments of 0.05 mm
(0.0020 in.), from 2.50 mm (0.0984 in.) to 3.30 mm (0.1299 in.).
(c) Install a new adjusting shim.
Place a new adjusting shim on the valve lifter.
Using SST (A), press down the valve lifter and re-
move SST (B).
SST 09248−06020, 09248 −55050 (09248−05510)
(d) Recheck the valve clearance.
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EM0494
−
ENGINE MECHANICAL VALVE CLEARANCE
EM−7
510
Author: Date:
1996 LAND CRUISER (RM451U)
9. Rear valves of No. 6 cylinder
ADJUST VALVE CLEARANCE
(a) Remove the distributor (See page IG−10).
(b) Remove the camshafts (See page EM−28).
(c) Remove the adjusting shim with a small screwdriver.
(d) Determine the replacement adjusting shim size by follow- ing the Formula or Charts:
Using a micrometer, measure the thickness of the
removed shim.
Calculate the thickness of a new shim so that the
valve clearance comes within specified value.
T ....... Thickness of removed shim
A ....... Measured valve clearance
N ....... Thickness of new shim
Intake: N = T + (A − 0.20 mm (0.008 in.))
Exhaust: N = T + (A − 0.30 mm (0.012 in.))
Select a new shim with a thickness as close as pos-
sible to the calculated value.
HINT:
Shims are available in 17 sized in increments of 0.05 mm
(0.0020 in.), from 2.50 mm (0.0984 in.) to 3.30 mm (0.1299 in.).
(e) Place a new adjusting shim on the valve lifters.
(f) Install the camshafts (See page EM−54 ).
(g) Recheck the valve clearance.
(h) Install the distributor (See page IG−11 ).
10. REINSTALL CYLINDER HEAD COVER
(a) Install the gasket to the cylinder head cover.
(b) Install the cylinder head cover with the 13 bolts.
11. RECONNECT HIGH −TENSION CORDS TO SPARK
PLUGS (See page IG−1 )
12. RECONNECT HEA TER VALVE AND ENGINE WIRE TO
COWL PANEL
(a) Connect the heater valve with the 2 bolts.
(b) Connect the ground strap and engine wire with the 2 bolts.
13. REINSTALL THROTTLE BODY (See page SF−48 )
14. REFILL RADIATOR WITH ENGINE COOLANT
15. CHECK AND ADJUST IGNITION TIMING (See page EM−10 )
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