Isuzu AU-4LE1T Maintenance Manual page 91

IMLE0027
86
Adjustment Procedure
1) Turn the crankshaft clockwise so that the TDC mark groove (1) on the
crank pulley is aligned with the TDC mark (cast out) on the timing gear
case cover.
2) Remove the cylinder head cover and check that the cylinder No. 1 is at
TDC in the compression stroke or at TDC in the exhaust stroke. When
the intake and exhaust valves are closed, the cylinder is at TDC in the
compression stroke, and when the intake and exhaust valves are open,
it is at TDC in the exhaust stroke.
3) Valve clearance is adjusted on 4 progressive steps as following.
Step 1: When the cylinder No. 1 is at TDC in the compression stroke,
measure and adjust the valve clearance of the cylinder No. 1
marked with ' ' in the table below.
Step 2: Turn the crankshaft clockwise 180 degrees from the step 1
condition to align the mark groove (2) with TDC mark on the
timing gear case cover.
Measure and adjust the valve clearance of the cylinder No. 3
marked with ' ' in the table below.
Step 3: Turn the crankshaft clockwise 180 degrees from the step 2
condition to align the mark groove (1) with TDC mark on the
timing gear case cover.
Measure and adjust the valve clearance of the cylinder No. 4
marked with ' ' in the table below.
Step 4: Turn the crankshaft clockwise 180 degrees from the step 3
condition to align the mark groove (2) with TDC mark on the
timing gear case cover.
Measure and adjust the valve clearance of the cylinder No. 2
marked with ' ' in the table below.