Valve Clearance Adjustment - Isuzu 4JB1 Service Information

00 – 46 SERVICE INFORMATION
1. Hold the accelerator pedal pad securely by hand, and
give it a full stroke.
2. Adjust the stopper bolt so that the clearance between
the pad stopper bolt and the rear side of the pad
becomes the specified length.
3. Check to see if the accelerator pedal play is in the
range of 5 to 10mm above the pedal pad.
0045-1.tif
4. Press down on the accelerator pedal fully and check
to see if the engine rotates at its maximum speed with
each of the linkage in the smooth operation.
5. In the operating range of accelerator pedal and the
injection pump lever returns to their respective original
positions without fail.

VALVE CLEARANCE ADJUSTMENT

1. Bring the piston in either the No. 1 cylinder or the No.
4 cylinder to TDC on the compression stroke by
turning the crankshaft until the crankshaft damper
pulley TDC line is aligned with the timing pointer.
0045-2.tif
2. Check the rocker arm shaft bracket nuts for
looseness.
Tighten any loose rocker arm shaft bracket nuts
before adjusting the valve clearance.
Rocker Arm Shaft
Bracket Nut Torque
0045-3.tif
3. 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.
If the No. 1 cylinder intake and exhaust valve push
rods are depressed, the No. 4 piston is at TDC on the
compression stroke.
0045-4.tif
0 - 2 (0 - 0.079)
N∙m (kg∙m/lb∙ft)
54 (5.5/40)
mm (in)