<p>The present invention relates to a rotary fuel pump (101). The pump (101) has a rotor (107) and at least one pumping element (115) for supplying high pressure fuel. A cam box (123) containing a cam arrangement (103) is provided for actuating the at least one pumping element (115). A speed dependent fuel pressure line (129) is provided for supplying speed dependent fuel pressure to an advance arrangement (125) for adjusting the timing of fuel delivery by the pump (101). A first vent line (131) is provided for venting air from the speed dependent fuel pressure line (129). The first vent line (131) is in fluid communication with a collection chamber (137) for collecting air vented from the speed dependent fuel pressure line (129). A second vent line (141) is provided for venting air from the collection chamber (137). The second vent line (141) is a helical groove (141) formed in the rotor (107) or a pump housing (105). The present invention also relates to a rotor (107) for a fuel pump (101).</p>
