LPG System Page 8A2–1
Page 8A2–1
Section 8A2
LPG System
ATTENTION
Before performing any Service Operation or other procedure described in this Section, refer to Section 00
CAUTIONS AND NOTES for correct workshop practices with regard to safety and/or property damage.
1 General Information............................................................................................................................... 2
1.1 Principals Of Operation.........................................................................................................................................2
Mixer........................................................................................................................................................................2
2 Service Operations................................................................................................................................3
2.1 Euro 2 Mixer............................................................................................................................................................3
2.2 LPG Set-up Procedure...........................................................................................................................................4
Preliminary Check..................................................................................................................................................5
Mixture Set-up ........................................................................................................................................................6
Tamper Proof Plug..............................................................................................................................................6
Mixture Adjustment.............................................................................................................................................7
2.3 Front Service Line..................................................................................................................................................8
3 Special Tools..........................................................................................................................................9
Techline
LPG System Page 8A2–2
Page 8A2–2
1 General Information
With the following exceptions, MY 2004 VY and V2 Series LPG system information carries over from MY 2003 VY Series
vehicles.
• Euro 2 Mixer
• LPG set-up procedure
• Front service line
To comply with Australian Design Rule ADR79, MY 2004 VY and V2 Series vehicles are fitted with the Impco Euro 2
tamper proof LPG mixer. The fuel mixture settings are set at the factory and should not require adjustment during normal
service. The mixer is a sealed unit, therefore, if a repair is required, the mixer will need to be replaced as a complete unit.
For information not contained in this Section, refer to Section 8A2 LPG System in the MY 2003 VY and V2 Series
Service Informatio n.
1.1 Principals Of Operation
Mixer
The mixer is installed between the engine intake manifold
and the intake air filter.
When the engine is cranked or running, manifold vacuum is
transmitted through vacuum ports in the air valve (1) to the
upper side of the mixer diaphragm (2). As a result,
atmospheric pressure pushing upwards on the underneath
side of the diaphragm, lifts it against the downward force of
the metering valve spring (3).
The pressure applied to the upper side of the diaphragm
varies with engine speed and throttle position. The pressure
difference betw een atm osp heric pressure act ing on the
underneath side of the diaphragm and the pressure acting
on the upper side of the diaphragm determines the metering
valve (4) position.
The position and the shape of the metering valve
determines, the amount of LPG vapour (5) delivered to the
engine.
Maximum fuel delivery is determined by the power valve (6),
which limits the maximum fuel flow. The power valve is pre-
calibrated in the factory and is not adjustable in service. Idle
air by-pass adjustment is provided by the adjustment screw
and once set, the mixture adjusters are sealed off with a
tamper proof blanking plug (7).
Figure 8A2 – 1
For a further description of the KL7 LPG system operation and components not covered in this section, refer to
Section 8A2, 2 Principals Of Operation in the MY 2003 VY and V2 Series Service Inform ation.
LPG System Page 8A2–3
Page 8A2–3
2 Service Operations
2.1 Euro 2 Mixer
LT Section No. – AA-650Q
Removal and reinstallation of the Impco Euro 2 tamper proof mixer fitted to the MY 2004 VY and V2 Series vehicles
carries over from the MY 2003 VY Series. However, Euro 2 tamper proof mixer components are not serviced and any
fault with the mixer where it requires an overhaul or repair will require the mixer to be replac ed as a complete unit.
The Impco Euro 2 mixture settings are set and sealed at the time of installation and should not require any further
adjustment of the mixtures during regular service. Where adjustment or repl acement of the Euro 2 mixer is required, the
idle mixture may need to be adjusted prior to installing a new tamper proof plug.
To adjust the mixture of the Impco Euro 2 mixer, a mixture adjusting tool is required, refer to 3 Special Tools.
For further mixture adjustment service information, refer to 2.2, LPG Set-up Procedure.
LPG System Page 8A2–4
Page 8A2–4
2.2 LPG Set-up Procedure.
If a new Euro 2 mixer has been installed or the LPG idle mixture is out of specification, the mixer will require adjustment.
Following completion of adjustment, the idle mixture adjuster is to be plugged with a steel blanking plug. New Euro 2
mixers are supplied with the power valve mixture set at the factory. However the tamper proof plug is not fitted but must
be done on mixer installation.
With exception to the following, the LPG set-up procedure for the MY 2004 VY and V2 Series vehicles carries over from
the MY 2003 VY Series Sedan.
• Idle Mixture Adjustment
• Tamper Proof Plugs
The LPG Set-up procedure allows the idle mixture to be adjusted under the following controlled conditions:
• Short and Long-Term Fuel Trim Cells set to zero.
• Fixed Spark advance.
• Fixed idle air control valve steps.
• Fuel control valve duty cycle fixed at 40%.
NOTE
Prior to adjusting the mixture or removing the
tamper proof plug, perform a Preliminary Check
to establish if the mixtures are set within the
specifications.
LPG System Page 8A2–5
Page 8A2–5
Preliminary Check
NOTE
The following procedure must be performed when
any LPG system component (mixer, converter,
FCV or PCM) has been replaced, overhauled,
reprogrammed, or when the engine assembly has
been replaced or overhauled.
1 Connect TECH 2 (4) to the DLC (1) with the adapter
(2) and cable (3).
NOTE
For further information on Tech 2 connection
and operation procedures refer to
Section 0C TECH 2.
2 With the vehicle in LPG mode, start the engine.
3 With no load on the engine, air conditioning off
(if fitted), all electrical consumers turned off and park
position selected, allow the engine and oxygen
sensors to reach operating temperature.
Figure 8A2 – 2
4 On TECH 2 select:
• F0: Diagnostics / (3) 2004 / VY/ F0: Engine / V6 /
F5: Function Tests / F5: LPG Set-up.
5 During the set-up procedure, Tech 2 ensures the
following engi ne opera ting conditions are met and
maintained:
• Engine Coolant Temperature greater than 91°C,
• Operating in closed loop mode,
• Right hand oxygen sensor is ready,
• The engine cooling fan is off, (engine coolant
temperature less than 104°C).
6 Once all the preconditions have been met, Tech 2 will
display the right-hand oxygen sensor voltage and
status.
Engine
LPG Setup
Right O2 Sensor
Righ t O2 Status 500 mV
Rich
VXLPG001
Confirm
Figure 8A2 – 3
7 If the right-hand oxygen sensor voltage is not as close to 500 mV as possible with the status of the right-hand
oxygen sensor not cons tantly toggling between rich and lean, the idle mixture will require adjustment, refer to
Mixture Adjustment in this Section.
LPG System Page 8A2–6
Page 8A2–6
Mixture Set-up
If the preliminary check shows that the idle mixture requires adjustment and the tamper proof plug has been installed, the
plug will require removing to gain access to the idle mixture adjuster.
The power valve adjustment is preset at the factory and must not be adjusted, therefore, the tamper proof plug does not
need to be removed.
New Euro 2 mixers are supplied with the power valve preset and the tamper proof plugs for the mixture and power valve
not installed. When fitting a new mixer, tamper proof plugs must be installed once the set-up procedure has been
completed.
Tamper Proof Plug
1 Remove the mixer, refer to Section 8A2, 3.21 Mixer in the MY 2003 VY and V2 Series Service Information.
NOTE
The tamper proof plugs fitted to the Euro 2 mixer
are surface hardened and will require this
hardening to be removed by carefully grinding the
top of the plug slightly prior to centre punching or
drilling.
2 Seal of both ends of the mixer (1) the LPG vapour inlet
port (2) and the vacuum line port (3) with masking tape
to prevent metal swarf from the grinding and drilling
process from entering the internals of the mixer.
3 Grind the top of the mixture adjuster tamper proof plug
(4) slightly to remove the surface hardening and centre
punch the plug.
4 Drill the centre of the tamper proof plug with a suitable
size drill bit for the screwdriver to be used in step 5.
Figure 8A2 – 4
5 Using a suitable size screwdriver (1), prise out the
tamper proof plug (2).
6 Remove the masking tape from the mixer prior to
reinstalling the mixer to the vehicle.
7 Reinstall the mixer to the vehicle, refer to Section 8A2,
3.21 Mixer in the MY 2003 VY and V2 Series Service
Information.
Figure 8A2 – 5
LPG System Page 8A2–7
Page 8A2–7
Mixt ure Adjustment
At the completion of the LPG set-up procedure the idle mixture adjuster will require resealing with a tamper proof plug.
There are two plugs fitted to the Impco Euro 2 mixer, one for the power valve adjuster and one for the idle mixture
adjuster. If a new mixer has been fitted the power valve adjuster will also require the fitting of a tamper proof plug.
1 Adjust the mixer as required, using the idle mixture
adjusting tool and adjust the idle mixture screw until
Tech 2 shows the right-hand oxygen sensor voltage is
as close to 500 mV as possible and the status of the
right oxygen sensor is constantly toggling between rich
and lean.
• An oxygen sensor voltage greater than 500 mV
indicates a rich mixture. Turn the idle mixture
screw anti-clockwise to lean-off the mixture.
• An oxygen sensor voltage of less than 500 mV
indicates a lean mixture. Turn the idle mixture
screw clockwise to richen the mixture.
NOTE
If the engine coolant temperature exceeds
104°C, the engine cooling fan will operate and
Tech 2 will suspend the set-up procedure. When
the engine cools, the cooling fan will cease
operation and Tech 2 will continue with the set-
up procedure.
Figure 8A2 – 6
2 Install the tamper proof plugs by positioning the power valve plug (1) if required, and mixture adjuster plug (2)
squarely to the mixer housing (3) and using a hammer, gently tap the tamper proof plug into the mixer until it is
level with the mixer housing, refer to Figure 8A2 – 7.
Figure 8A2 – 7
LPG System Page 8A2–8
Page 8A2–8
2.3 Front Service Line
The removal and reinstallation procedure of the front service line carries over from the MY 2003 VY Series vehicles .
However, due to the fitment of close coupled catalytic converters in the exhaust system required for Australian Design
Rule ADR79, it is recommended to remove the right-hand front exhaust assembly, refer to Section 8B Exhaust System.
For front service line service information, refer to Section 8A2, 3.14 Front Service Line in the MY 2003 VY and V2 Series
Service Informatio n.
LPG System Page 8A2–9
Page 8A2–9
3 Special Tools
With the following exception, LPG special tool requirements for the MY 2004 VY and V2 Series KL7 LPG system carry
over from the MY 2003 VY Series. For further information relating to special tools, refer to Section 8A2, 10 Special Tools
in the MY 2003 VY and V2 Series Service Information.
• Mixer Idle Adjusting Tool
Tool Number Illustration Description Tool Classification
T7 – 17392
Idle Mixture Adjuster
Used to adjust idle mixtures.
Mandatory