Auxiliary injector

An auxiliary injector arrangement in a dual fuel supply system for an internal combustion engine, the dual fuel supply system comprising a main fuel supply system to supply at least a first fuel using at least one main liquid fuel injector into at least an inlet manifold adjacent each engine cylinder of the engine, and an auxiliary fuel supply system, wherein:

• the inlet manifold includes a throttle body;
• the inlet manifold is divided downstream of the throttle body to supply air to each of the cylinders of the internal combustion engine;
• the auxiliary fuel supply system includes at least one injector for a second fuel, mounted in or adjacent the throttle body upstream or downstream of a throttle valve in the throttle body, and adapted to supply said second fuel at times when the at least one main injector cannot supply a sufficient amount of said first fuel;
• and
• the second fuel, supplied by the auxiliary injector, is petrol.