immobiliser? why didnt you mention this at the start? is it a home job immob, eg its just earths the coil or the ignition or a shop bought one, sounds like the wiring has been jiggered with either way and probably a wiring issue in the ignition, also unusual for a fuel pump just to shit its self, has this been changed to an electric pump? or does the immob have a fuel cut off switch in it aswell?