Page 787 of 1399

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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Page 792 of 1399

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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EM1E3−01
EM−28
−
ENGINE MECHANICAL CYLINDER HEAD
1996 LAND CRUISER (RM451U)
REMOVAL
1. DRAIN ENGINE COOLANT
2. REMOVE BATTERY AND BATTERY TRAY
(a) Disconnect the battery cables.
(b) Remove the nuts, hold −down clamp and battery.
(c) Remove the bolt and disconnect the ground strap.
(d) Remove the 5 bolts and battery tray.
3. REMOVE AIR CLEANER HOSE AND CAP
4. DISCONNECT CRUISE CONTROL ACTUATOR CABLE FROM THROTTLE BODY
5. DISCONNECT ACCELERATOR CABLE FROM
THROTTLE BODY
6. DISCONNECT THROTTLE CABLE FROM THROTTLE BODY
7. DISCONNECT ENGINE GROUND STRAPS
(a) Disconnect the ground strap from the No. 1 engine hang-
er.
(b) Disconnect the ground strap from the air intake chamber.
8. DISCONNECT CONNECTOR ON INTAKE MANIFOLD FROM LH FENDER APRON
9. DISCONNECT BRAKE BOOSTER VACUUM HOSE
10. DISCONNECT EVAP HOSE
11. DISCONNECT FUEL RETURN HOSE
12. DISCONNECT HEATER HOSES
13. DISCONNECT ENGINE WIRE AND HEATER VALVE FROM COWL PANEL
(a) Remove the 2 bolts and disconnect the engine wire and
ground strap.
(b) Remove the 2 bolts and disconnect the heater valve.
14. REMOVE NO. 2 AND NO. 3 CYLINDER HEAD COVERS
Remove the 4 bolts and head covers.
15. REMOVE DISTRIBUTOR (See page IG−10 )
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P08374A16075
1 Dot Mark
EM−32
−
ENGINE MECHANICAL CYLINDER HEAD
1996 LAND CRUISER (RM451U)
30. REMOVE CYLINDER HEAD COVER
Remove the 13 bolts, cylinder head cover and gasket.
31. REMOVE SPARK PLUGS
32. SET NO. 1 CYLINDER TO TDC/COMPRESSION
(a) Turn the crankshaft pulley and align its groove with the ”0”
mark on 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.
33. REMOVE CHAIN TENSIONER
Remove the 2 nuts, chain tensioner and gasket.
34. REMOVE CAMSHAFT TIMING GEAR
(a) Remove the semi−circular plug.
(b) Place the matchmarks on the camshaft timing gear and timing chain.
(c) Hold the intake camshaft with a wrench, remove the bolt and distributor gear.
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P08374A16075
1 Dot Mark
EM−58
−
ENGINE MECHANICAL CYLINDER HEAD
1996 LAND CRUISER (RM451U)
4. 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) Turn the camshafts so that the timing marks with 1 and 2 dots will be in straight line on the cylinder head surface as
shown in the illustration.
5. INSTALL CAMSHAFT TIMING GEAR
HINT:
Check that the matchmarks on the camshaft timing gear and
timing chain are aligned.
(a) Place the gear over the straight pin of the intake cam- shaft.
(b) Align the straight pin of distributor gear with the straight pin groove of the intake camshaft gear as shown.
(c) Hold the intake camshaft with a wrench, install and torque
the bolt.
Torque: 74 N·m (750 kgf·cm, 54 ft·lbf)
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−
ENGINE MECHANICAL CYLINDER HEAD
EM−63
1996 LAND CRUISER (RM451U)
24. CONNECT NO. 3 WATER BYPASS HOSE
25. CONNECT RADIATOR INLET HOSE
26. CONNECT PS RESERVOIR TANK
Connect the reservoir tank with the 3 bolts.
Torque: 20 N·m (200 kgf·cm, 14 ft·lbf)
27. INSTALL DISTRIBUTOR (See page IG−11)
28. INSTALL NO. 2 AND NO. 3 CYLINDER HEAD COVERS
Install the head covers with the 4 bolts.
29. CONNECT HEATER VALVE AND ENGINE WIRE TO COWL PANEL
(a) Connect the heater valve with the 2 bolts.
(b) Connect the engine wire and ground strap with the 2 bolts.
30. CONNECT HEATER HOSES
31. CONNECT FUEL RETURN HOSE
32. CONNECT EVAP HOSE
33. CONNECT BRAKE BOOSTER VACUUM HOSE
34. CONNECT CONNECTOR ON INTAKE MANIFOLD TO LH FENDER APRON
35. CONNECT ENGINE GROUND STRAPS
(a) Connect the ground strap to the No. 1 engine hanger.
(b) Connect the ground strap to the air intake chamber.
36. CONNECT THROTTLE CABLE TO THROTTLE BODY
37. CONNECT ACCELERATOR CABLE TO THROTTLE
BODY
38. CONNECT CRUISE CONTROL ACTUATOR CABLE TO
THROTTLE BODY
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IG0IB−02
SPARK TEST
TRY ANOTHER IGNITERNO
OK
OK
OK
OK
OK
BAD
BAD
BAD
BAD
BAD
BADConnect securely.
Replace the cord(s).
Replace the distributor housing assembly.
Check wiring between ECM, ignition coil and
igniter, and then try another ECM.
CHECK CONNECTION OF IGNITION COIL, IGNITER AND
DISTRIBUTOR CONNECTOR
CHECK RESISTANCE OF HIGH−
TENSION CORD
(See step 8)
Maximum resistance: 25 k Ω per cord
CHECK RESISTANCE OF IGNITION COIL (See step 24)
Resistance: Cold Hot
Primary 0.36 − 0.55 Ω 0.45 − 0.65 Ω
Secondary 9.0 − 15.4 kΩ 11.4 − 18.1 kΩ
CHECK AIR GAP OF DISTRIBUTOR (See step 31)
Air gap: 0.2 − 0.4 mm (0.008 −0.016 in.)
OK
CHECK RESISTANCE OF SIGNAL GENERATOR
(PICKUP COIL) (See step 32)
Resistance: Cold Hot
G1 and G− 185 − 275 Ω 240 − 325 Ω
G2 and G− 185 − 275 Ω 240 − 325 Ω
NE and G − 185 − 275 Ω 240 − 325 Ω
CHECK IGT SIGNAL FROM ECM
(See page DI−93 ) Check
wiring between ignition switch to ignition
coil and igniter.
Replace the ignition coil.
Replace the distributor housing assembly.
BAD
OK
CHECK
POWER SUPPLY TO IGNITION COIL AND IGNITER
1. Turn ignition switch to ON.
2. Check that there is battery voltage at ignition coil positive (+)
terminal.
−
IGNITION IGNITION SYSTEM
IG−1
735
Author: Date:
1996 LAND CRUISER (RM451U)
IGNITION SYSTEM
ON−VEHICLE INSPECTION
1. CHECK THAT SPARK OCCURS
(a) Disconnect the high −tension cords (from the ignition coil)
from the distributor cap.
(b) Hold the end approx. 12.5 mm (0.50 in.) from the body ground.
(c) Check if spark occurs while engine is being cranked.
HINT:
To prevent gasoline from being injected from injectors during
this test, crank the engine for no more than 1 − 2 seconds at a
time.
If the spark does not occur, do the test as follows:
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