G643(E) Service Manual
Chapter 6. LPG FUEL DELIVERY SYSTEM
214
Tests and Adjustments
WARNING – PROPER USE
•
LP gas is highly flammable. To prevent perso-
nal injury, keep fire and flammable materials
away from the lift truck when work is done on
the fuel system.
•
Gas vapor may reduce oxygen available for
breathing, cause headache, nausea, dizziness
and unconsciousness and lead to injury or
death. Always operate the forklift in a well
ventilated area
•
Liquid propane may cause freezing of tissue or
frostbite. Avoid direct contact with skin or
tissue; always wear appropriate safety
protection including gloves and safety glasses
when working with liquid propane.
N-2001 Regulator Service Testing
For checking the N-2001 regulator/converter
operation, the following tests can be performed. To
check the secondary regulation (output) a simple
vacuum hand pump can be used to simulate the
vacuum signal transmitted from the air/fuel mixer
when the engine is running. See listing below for
required hardware.
Break-Off Test
Secondary Stage Test Hardware
1.
Hand vacuum pump
2.
Regulator vapor outlet test fitting 3/4” NPT x 1/4”
hose barb
3.
Union Tee 1/4” NPT with three 1/4” NPT x 1/4”
hose barb
4.
Vacuum hose
5.
0-3” WC Magnehelic gauge (inches of water
column)
Secondary Stage (Break-Off) Test
1.
Connect the vacuum pump, the Magnehelic
gauge and the regulator vapor outlet to the Union
Tee fitting (Figure 30). Make sure there is no
leakage at any of the fittings.
2.
Using the vacuum pump slowly apply enough
vacuum to measure above -2” WC on the gauge.
This vacuum signal opens the secondary valve in
the N-2001 regulator/converter.
3.
Release the vacuum pump lever and you will see
the gauge needle start falling back toward zero.
When the pressure drops just below the specified
break-off pressure (-1.2 “ WC) of the secondary
spring, the needle should stop moving.
4.
At this point the secondary valve should close. If
the secondary valve seat or the secondary
diaphragm is leaking the gauge needle will
continue to fall toward zero (proportional to the
leak size). An excessively rich air/fuel mixture can
be caused by a secondary valve seat leak and the
regulator should be replaced.
Figure 30. Secondary Stage Test Connection
