S10/T10 Blazer 4WD V6-262 4.3L VIN Z (1994)
Rocker Arm Assembly: Adjustments
VALVE ADJUSTMENT
Fig. 10 Valve Adjustment
The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures.
TYPE 1 - VIN Z
If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve
train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb).
TYPE 2 - VIN Z
If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below.
1. Remove rocker arm cover.
2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No.
1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not
moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated
one revolution.
3. With engine in No. 1 cylinder firing position, adjust the following valves:
^
Exhaust valves 1, 5 and 6.
^
Intake valves 1, 2 and 3.
NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine.
4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while
turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger.
5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder
firing position. With engine in this position, adjust the following valves:
^
Exhaust valves 2, 3 and 4.
^
Intake valves 4, 5 and 6.
6. Install valve covers and related components, then start engine and check timing and idle speed.
