Service manual

G420F(FE) Service Manual Chapter 6. LPG FUEL DELIVERY SYSTEM 229
Power Valve Adjustment
1. The power valve should only be adjusted after the
idle screw has been adjusted properly. The
engine and vehicle drive train and hydraulics
should also be at normal operating temperatures.
2. Apply a load to the engine while the engine is
operating above idle speed. Torque converter stall
is the preferred operating mode for this test. If a
torque converter speed test cannot be performed,
the engine can be run at another speed (max
governor), but a load must be applied by using
hydraulics.
The power valve should be adjusted to obtain
maximum torque converter stall speed.
NOTE : While adjusting the power valve, do not hold
engine at load point for longer than 5-10 seconds.
Holding for a longer period of time will cause the fuel
temperature to drop, which could adversely affect
the power valve setting.
3. Once the power valve is set, bring the engine
back to idle and verify the idle screw setting.
Figure 43. Main Mixture Adjustment on Bottom of
Mixer (partial view)