NZQA Expiring unit standard
951 version 6
Page 1 of 4
Title
Diagnose and rectify faults in a vehicle LPG (liquefied petroleum gas)
fuel system
Level
4
Credits
4
Purpose
This unit standard is for people in the automotive repair
industry. People credited with this unit standard are able to:
carry out regular maintenance procedures to an LPG fuel
system; demonstrate knowledge of engine tuning procedures
and equipment malfunction causes on LPG fuelled vehicles;
test an LPG fuel system for faults; and rectify LPG fuel system
faults and their causes.
Classification
Motor Industry > Automotive Fuel Systems and Exhaust
Available grade
Achieved
Entry information
Critical health and
safety prerequisites
Unit 886, Test a four stroke petrol engine using a tunescope;
and Unit 894, Diagnose and rectify faults in a carburetted petrol
fuel system; or demonstrate equivalent knowledge and skills.
Explanatory notes
1
The person completing this unit standard must be directly supervised by an
Alternative Fuels Authorised Person.
2
The following legislation, regulations, and their amendments are required to be
consulted and followed where applicable:
– Health and Safety in Employment Act, 1992
– Traffic Regulations, 1976
– NZ Standards: NZS 5422, and NZS 5463.
3
Reference to suitable tools and equipment means industry approved tools and
equipment that are recognised within the industry as being the most suited to
complete the task to a professional and competent manner with due regard to safe
working practices.
NZ Motor Industry Training Organisation
(Incorporated)
SSB Code 101542
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
951 version 6
Page 2 of 4
Outcomes and evidence requirements
Outcome 1
Carry out regular maintenance procedures to an LPG fuel system.
Evidence requirements
1.1
Safety precautions are taken when carrying out maintenance work according to
NZS 5422 and NZS 5463.
1.2
Suitable tools and equipment are selected and used to enable the system to be
serviced.
1.3
Regular maintenance requirements to the gaseous fuel equipment are
completed, according to equipment manufacturer's instructions and NZS 5422
and NZS 5463.
Range
filter cleaning, regulator draining, air filter, leak detection, security
of components, petrol hose condition, mixer attachment.
Outcome 2
Demonstrate knowledge of engine tuning procedures and equipment malfunction causes
on LPG fuelled vehicles.
Evidence requirements
2.1
Problems that may affect engine operation following the fitment of conversion
systems are identified.
Range
2.2
Problems that may occur with LPG components in service are described
according to the equipment manufacturer's service information.
Range
2.3
malfunctions related to fuel supply and gas usage.
mechanical and electrical faults, lack of servicing, external
problems affecting performance.
The procedure to perform on-road acceleration tests is described according to
manufacturer’s engine test instructions.
Range
hesitation, misfiring, flat spots, overall performance.
NZ Motor Industry Training Organisation
(Incorporated)
SSB Code 101542
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
2.4
The use of a rolling chassis dynamometer and an infra-red exhaust gas
analyser for carrying out adjustment and test procedures on an engine
operating on dual fuel is explained according to manufacturer’s equipment
instructions.
Range
2.5
951 version 6
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engine under load conditions throughout revolutions per minute
(RPM) range.
The modification requirements required for vehicles to run on dedicated LPG
are explained according to manufacturer’s kit instructions.
Range
removal of existing petrol system components, fitting of gas
carburettor components, alterations to compression ratio, ignition
components, ignition timing, exhaust emission controls, air intake
systems, valve and valve seat modifications, turbocharging,
intercooling.
Outcome 3
Test an LPG fuel system for faults.
Range
equipment malfunction, poor starting, poor performance.
Evidence requirements
3.1
Safety precautions are taken when carrying out tests according to NZS 5422
and NZS 5463.
3.2
Suitable tools and equipment are selected and used to enable the system to be
tested.
3.3
The vehicle is operated to reproduce the symptoms of the fault reported by the
customer or supervisor, and all details concerning the symptoms and the
conditions when they occur are identified and noted.
3.4
The fault symptoms, the conditions when they occur, and any test results are
analysed, and a likely cause is determined.
Outcome 4
Rectify LPG fuel system faults and their causes.
Evidence requirements
4.1
Safety precautions are taken when carrying out repair work according to NZS
5422 and NZS 5463.
4.2
Suitable tools and equipment are selected and used to enable system faults to
be rectified.
NZ Motor Industry Training Organisation
(Incorporated)
SSB Code 101542
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
951 version 6
Page 4 of 4
4.3
Faulty LPG system components are repaired and replaced according to
equipment manufacturer's specifications, and comply with NZS 5422, Part 1.
4.4
A leak test is performed according to NZS 5422, Part 1.
Range
after repairs and after replacement of components.
Replacement information
This unit standard has been replaced by unit standard
24181 and unit standard 24182.
This unit standard is expiring. Assessment against the standard must take place by
the last date for assessment set out below.
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
9 November 1993
31 December 2016
Review
2
4 October 1996
31 December 2016
Review
3
26 February 1999
31 December 2016
Review
4
25 January 2008
31 December 2016
Rollover
5
19 November 2010
31 December 2016
Rollover
6
20 November 2015
31 December 2020
Consent and Moderation Requirements (CMR) reference
0014
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA, or
an inter-institutional body with delegated authority for quality assurance, before they can
report credits from assessment against unit standards or deliver courses of study leading
to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Consent requirements and an outline of the moderation system that applies to this
standard are outlined in the Conesnt and Moderation Requirements (CMR). The CMR
also includes useful information about special requirements for organisations wishing to
develop education and training programmes, such as minimum qualifications for tutors and
assessors, and special resource requirements.
NZ Motor Industry Training Organisation
(Incorporated)
SSB Code 101542
 New Zealand Qualifications Authority 2016