LPG Systems - System Complexity

Basic System Layout

LPG systems provide a complete secondary fuel system for the vehicle. They are generally designed to run with petrol engines. The type of system used should match the type of vehicle.

Basic System Types

Venturi

These systems are sometime known as 1st generation. They are highly inaccurate and work by mixing Autogas with air using a simple venturi or 'cooker' ring. There are no electronic controls and therefore no lambda control . LSV does not supply these simple systems as they are suitable only for vehicles with carburettor engines.

Single Point Analogue

These systems are not microprocessor controlled and can be used on vehicles with a 3-way catalytic converter. They have a single injector and are most suitable for older petrol injection vehicles. These older systems are not supplied by ;SV because they have now largely been replaced by more modern microprocessor controlled systems that are more accurate, reliable and environmentally friendly.

Single or Multipoint Microprocessor

These are fully microprocessor controlled systems suitable for modern single or petrol multi-point injection systems. They work by having a second LPG ECU which operates the LPG injectors from signals given by the existing petrol ECU . They are suitable for vehicles with 3 way catalytic converters but do not perfectly emulate the petrol injection system. Some emissions reduction can be achieved.

Multipoint Sequential Microprocessor

Key 1 7 2 8 3 9 4 10 5 11 6

1. Microprocessor	7. TPS sensor
2. Fuel switch	8. Injector LPG
3. Fuel switch	9. Lambda sensor
4. MAP sensor	10.RPM sensor
5. Vaporizer	11. LPG tank
6. Shutoff valve LPG

These are the latest systems on the market and are ideal for both emissions reduction and fuel efficiency. This new generation of Sequential Gas Injection (SGi) systems work by 'reading' the data sent to each petrol injector and using this information to control the LPG injectors. Effectively the petrol engine management system is controlling the LPG via a computer interface that translates the raw data to compensate for the different characteristics between LPG and Petrol. Each system needs to be tailored to the vehicle by the installer.

All Vehicle manufacturers who have LPG variants in their range use this equipment as it is very reliable and offers consistent emission reduction. LSV only use and recommend this type of equipment as being most suitable for modern vehicles and being the most environmentally friendly.