Operation Section 1 ± 6 3. SUPPLY PUMP 3.1 Outline The HP3 and HP4 supply pumps have the same construction and operational characteristics as the conventional supply pumps. Supply pumps place fuel suctioned from the fuel tank under high pressure for delivery to the rail. A feed pump outlet, and pump inlet have been added to the 2010 model supply pump to inhibit air mixing. As a result of this change, the fuel flow has been altered to travel through the following path: main filter, feed pump, bubble separator, pump unit. (1) 2004 model 7': *YIP8IQTIVEXYVI7IRWSV HP3 (294000-025#) 5) *YIP8IQTIVEXYVI7IRWSV 7': 5) HP4 (294050-001#)