Chapter 9 Test And Adjustments; N2001 Service Testing - Daewoo G420E Service Manual

CHAPTER 9 TEST AND ADJUSTMENTS

WARNING
LP gas is highly flammable. To prevent
personal 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.
CAUTION
The regulator/converter and mixer are
part of a certified system complying with
EPA and CARB 2004 requirements. Only
trained certified technicians should
perform disassemble, service or
replacement of the regulator/converter or
mixer.
Tier
G420E/G424E LP Engine

N2001 Service Testing

After overhaul or for simply checking the N2001
regulator/converter operation, the following tests can
be performed (See Chapter 7 for removal/installation
of the N2001). 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. You will
need the following hardware:
Secondary Stage Test Hardware
1. Hand vacuum pump.
2. Regulator vapor outlet test fitting ¾" NPT X ¼"
hose barb.
3. Union Tee ¼" NPT with three ¼" NPT X ¼" hose
barb.
4. Vacuum hose.
5. 0-3 in W.C. Magnehelic Gauge (inches of water
column).
Secondary Stage (Break-Off) Test
1. Connect the vacuum pump, the Magnahelic
gauge and the regulator vapor outlet to the Union
Tee fitting (Figure R11). Make sure there is no
leakage at any of the fittings.
2. Using the vacuum pump slowly apply enough
vacuum to measure above -2 in WC on the gauge.
This vacuum signal opens the secondary valve in
the N2001 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 in 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, repair
as necessary (See Chapter 7 for disassembly of
the N2001).
78 Test And Adjustments