DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the injector includes a body 10 which comprises a front body part 11 which can for example have a threaded end 12 for engagement in a threaded port associated with an engine, and a rear body part 13. An inlet 15 is provided in the body 10, the inlet 15 having a non-return valve 16 operated by spring 17. In use, fuel is supplied or induced under low pressure into the inlet 15 sufficient to overcome the action of spring 17. The strength of spring 17 is not critical. The fuel pressure can be relatively low so that high pressure fuel lines are not required.

An outlet 20 has an associated non-return valve 21 acting by means of spring 22, the strength of which is not critical. With this arrangement, fuel can continuously be pumped or induced under low pressure into inlet 15, through passage 25 and out through outlet 20. This continuous fuel flow can provide cooling although supplementary cooling could be provided.