V8DualFuel: LPG / Autogas Conversions and kits

LPG / Autogas conversions and Kits from the experts


V8DualFuel from RPi Engineering: LPG / Autogas Conversions and kits for the Rover V8 Engine
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All about LPG
 

Modern cars are filled with electronics

These electronics provide the driver with information when one of the measurements is out of tolerance. When an LPG system is installed, the motor management system detects that the fuel injection has stopped, the lambda signal has changed etc.

The modern LPG system has to cope with these problems.

According to the car there will be installed:
  • Injection simulation
  • Lambda simulation
  • Auto petrol start (can default to starting on gas if required)

Injection simulation


The injection simulator has 3 functions
  • shut down the need for petrol injection by blocking off the signals to the injectors (includes simulated feedback)
  • Ensure the engine management system (ECU) does not go into default by giving a simulated signal as if it were the injectors, thus keeping the ECU happy
  • avoid the chance of getting a back-fire by delaying shutting down of the petrol injection by several seconds after activating the LPG system

Lambda simulation


If an engine has a constant-learning motor management system (later Efi types) a Lambda simulator has to be installed.

This type of engine management system will try to reduce the amount of fuel constantly until it gets the correct mixture reading out of the lambda probe. Because the LPG computer is regulating the fuel mixture (LPG) the Lambda will give a Lambda 1 read out to the Engine ECU, which in turn will mistakenly continue to lower the assumed injected amount of petrol and still get a lambda 1. This will result in further lowering of the amount of petrol until the system goes into default. The reason for this is the LPG ECU is running the engine fuel management and the Petrol ECU only thinks it is, but switching back to petrol means it has lowered itself so weak on fuel it can take some miles for the system to re-calibrate itself, hence the need for Lambda simulation For later gems type injection systems chipping is also an essential part of the conversion and to get over this problem it does it by removing the robust security that is at present unhelpfully protecting the ECU from being fooled.

Auto Petrol Start


There are many rumours that a dual fuel vehicle has to start on petrol and then be switched over to LPG. Whilst this is the default scenario as petrol starting is preferred, it is completely automatic, and in most cases almost instant. However, it is possible to override this and starting and running completely on LPG is not a problem.