Remove the timing bolt and turn the flywheel 360
degrees in the direction of engine rotation. This will put
No.1 piston at top center (TC) position on the opposite
stroke. Install the timing bolt in the flywheel.
With No. 1 piston at top center position on the opposite
stroke, adjustment can be made to the remainder of the
POSITIONS FOR FUEL TIMING AND VALVE LASH
Repeat Steps 3, 4 and 5 for these valve adjustments.
Remove the timing bolt from the flywheel when all valve
lashes have been adjusted.
(WasteGate - If Equipped)
The wastegate turbocharger (if equipped) senses boost
pressure which actuates the wastegate valve which will control
the amount of exhaust gas that will be allowed to bypass the
turbine side of the turbocharger. The speed of the
turbocharger is controlled by the wastegate valve.
(1) Actuating rod. (2) Canister. (3) Line.
When the engine is operating under low boost (lug) conditions
a spring pushes against a diaphragm in canister (2) and moves
actuating lever (1) to close the wastegate valve which will allow
the turbocharger to operate at maximum performance.
As the boot pressure increases against the diaphragm in
canister (2), the wastegate valve is opened and the rpm of the
turbocharger is limited by bypassing a portion of the exhaust
gases past the turbine wheel of the turbocharger.
An indication of a problem with the wastegate turbocharger is:
boost pressure is too high at rated rpm.
boost pressure is too low at lug conditions.
The correct pressure for the inlet manifold is given in the TMI
To check the operation of the wastegate valve, remove line (3)
and slowly apply 200 kPa (29 psi) of air to canister (2). DO
NOT EXCEED 200 kPa (29 psi). The actuating lever should
move more than .50 mm (.020 in) when the external supply of
air is connected to line (3). If the actuating lever does not
move at least .50 mm (.020 in), replace the turbine housing
assembly (includes wastegate), or the complete turbocharger.
The wastegate turbine housing assembly is preset
at the factory and no adjustments can be made.
Maximum rpm of the turbocharger is controlled by the boost
pressure (which controls the position of the wastegate valve),
the fuel setting, the high idle rpm setting and the height above
sea level at which the engine is operated.
If the high idle rpm or the fuel setting is higher than given
in the TMI (Technical Marketing Information) Governor
Bench Performance Data (for the height above sea level at
which the engine is operated), there can be damage to
engine or turbocharger parts. Damage will result when
increased heat and/or friction due to the higher engine
output goes beyond the engine cooling and lubrication
systems abilities. A mechanic that has the proper training
is the only one to make the adjustment of fuel setting and
high idle rpm setting.