Kerry Edwards,

If I had an air leak, I would assume I would see air bubbles or a low fuel level in the pre filter, (my pre filter is clear), but I do not. It is full with diesel - no air and no air bubbles.

When you say a purge fuel, do you mean something like diesel kleen or some other fuel injector cleaner? No I have not. Do you think my problem is caused by dirty injectors? If so, wouldn't a dirty injector perform worse on a thicker fuel like veggi oil?