A & C. .. .Many thanks.. .. .Having spent some considerable time with the fuel system drawing recently, I understand what you are saying and am reassured.. .. .Presumably the large increase/decrease in indicated fuel pressure is also influenced by the location of the sensor (on the bypass line) and also the operation of the pumps in series, rather than the parallel arrangement on the PA28s I have most hours on.. .. .Thanks for taking the time to help my education! <img border="0" title="" alt="[Smile]" src="smile.gif" />. . . . <small>[ 07 March 2002, 14:55: Message edited by: Final 3 Greens ]</small>