Service manual

ENGINE ADJUSTMENTS
VALVE CLEARANCE ADJUSTMENT
1. Warm the engine to nonnal operating temperature.
2. Pull off the air breather pipe from the rocker cover.
Remove the rocker cover bolts and remove the rocker
cover to expose the rocker shaft and valve assembly.
3. Remove the glow plugs from each
of the cylinders to
enable the crankshaft to be easily rotated by hand to posi-
tion each cylinder for valve adjustment.
Valves are adjusted with the piston in the cylinder being
adjusted at
IDC of its compression stroke.
NOTE: Retorque the cylinder head bolts before adjusting the
engine's valves.
4. Loosen the head bolts in the reverse order of tightening.
18
17
13
9
5 4
8
5. Tighten the head bolts in the order shown.
Cylinder Head BoltTorque 8590 It ·Ib (11.8 -12.5 m-kg)
12
6. Set the piston of No.1 cylinder to IDC (compression)
and check the valve clearance at each position indicated.
If the clearance is incorrect, adjust to specifications:
Intake -
No.1 and No.2 cylinders; and
Exhaust - No. 1 and
No.3 cylinders.
7. Turn the crankshaft once, setting the piston
of No.4
cylinder at IDC (compression) and adjust to the follow-
ing specifications:
Intake -
No.3 and No.4 cylinders; and
Exhaust -
No.2 and No.4 cylinders.
WHEN NO.4 CYLINDER IS AT TOP DEAD CENTER
I ,
41NTAKE 31NTAKE
4 EXHAUST EXHAUST 2
INTAKE 1
I
3 EXHAUST 1 EXHAUST
I I I
WHEN NO.1 CYLINDER IS AT TOP DEAD CENTER
8. Adjust each valve's clearance by inserting a 0.012in
(O.03mm)
feeler gauge between the rocker arm and the
valve stem. Make sure to adjust all valves when the
engine is cold.
9. Install the cylinder head cover.
Head Cover Bolt Torque 2 - 3 It -Ib (0.3 - 0.45 m-kg)
ENGINE COMPRESSION
Check the compression pressure. To do this, warm the
engine, remove all fuel injectors, or glow plugs, disconnect
the fuel shut-off solenoid wire, and install a compression
adapter in the injector hole or glow plug hole. Connect a
compression tester on the adapter and crank the engine with
the starter motor until the pressure reaches a maximum value.
Repeat this process for each cylinder. Look for cylinders with
dramatically (at least
20%) lower compression than the aver-
age
of the others. Compression pressure should not differ by
more than 42.7 psi
(3.0 kglcm
2
)
at 200 rpm.
~
INJECTOR HOLE
OR GLOW PLUG HOLE
Compression pressure standard 427 psi at 200 rpm (30.0 kg/em')
Compression pressure limit 384 psi at 200 rpm (27.0 kg/em')
If a weak cylinder is flanked by healthy cylinder, the problem
is either valve or piston related. Check the valve clearances
for the weak cylinder, adjust as needed and test again.
If the cylinder is still low, apply a small amount of oil into
the cylinder to seal the rings and repeat the test.
If compression comes up - the rings are faulty.
Engines & Generators
39