Abstract: A fuel injection system for injecting liquid LPG or CNG into an air inlet duct of an internal combustion engine. The fuel injection system including an adaptor ring which is adapted to be mounted into the air intake duct for the engine upstream or downstream of the throttle valve in the inlet duct so as to allow air flow through. There is at least one pod mounted into the adaptor ring with each pod including a fuel inlet, a fuel outlet and a hollow space within the pod into which the fuel inlet and fuel outlet open and a liquid fuel injector mounted into the or each pod. Fuel enters the injector from the hollow space within the pod to be injected therefrom into the inlet duct. An injector control arrangement acting upon engine parameters and demand parameters controls the or each injector to inject liquid fuel into the engine as required. Each of the injectors may be bottom feed flow-through injectors.

Abstract: A method and an arrangement for determining the presence of heat soak conditions in an internal combustion engine (1) of a type using fuel injection. Particularly useful when the or one of the fuels used in the engine (1) is susceptible to vaporisation in a fuel rail (8) due to high engine temperatures. The method includes the steps of measuring a first temperature in a tank (10) for the fuel, measuring a second temperature at the fuel rail (8), ascertaining the difference between the first and second temperature, wherein a significant difference indicates heat soak conditions. If heat soak conditions are detected then an auxiliary injector (20) may be operated or in dual fuel engines a higher boiling point fuel may be used.

Abstract: An auxiliary injector arrangement in a fuel supply system for an internal combustion engine. The auxiliary injector arrangement includes at least one injector mounted in the inlet manifold upstream or downstream of the throttle and adapted to supply fuel at times when the main fuel supply system cannot supply sufficient fuel. The main fuel supply system and the auxiliary injector may be operated on LPG, natural gas or petrol. The auxiliary injector may be a liquid fuel injector or gaseous fuel injector.