Isuzu 4JB1, Service Information

Page: 45 / 60

SERVICE INFORMATION 00 – 47
Adjust the No. 1 or the No. 4 cylinder valve clearance
while their respective cylinders are at TDC on the
compression stroke.
Valve Clearance (At Cold) mm (in)
0.4 (0.016)
4. Loosen each valve clearance adjusting screw as
shown in the illustration.
5. Insert a feeler gauge of the appropriate thickness
between the rocker arm and the valve stem end.
6. Turn the valve clearance adjusting screw until a slight
drag can be felt on the feeler gauge.
7. Tighten the lock nut securely.
8. Rotate the crankshaft 360°.
9. Realign the crankshaft damper pulley TDC notched
line with the timing pointer.
10. Adjust the clearance for the remaining valves as
shown in the illustration.
INJECTION TIMING ADJUSTMENT
1. Check that the notched line on the injection pump
flange is aligned with the front plate or the timing gear
case notched line.
2. Bring the piston in the No.
!
cylinder to TDC 1 on the
compression stroke by turning the crankshaft until the
crankshaft pulley TDC line is aligned with the timing
mark
"
.
Note:
Check for play in the No. 1 intake and exhaust valve
push rods.
If the No. 1 cylinder intake and exhaust valve push
rods have play, the No. 1 piston is at TDC on the
compression stroke.
3. Disconnect the injection pipe from the injection pump.
4. Remove one bolt from the distributor head.
5. Insert a screwdriver into a hole in the fast idle lever
and turn the lever to release the W-C.S.D. function. (If
so equipped)
6. Install the static timing gauge
#
.
The probe of the gauge should be depressed inward
approximately 2 mm (0.079 in).
Static Timing Gauge : 5-8840-0145-0 (J-28827)
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