Hi All - Want to introduce myself. New to posting, followed the forum for years. We own a 2005 44 CPMY ES. Twin VOLVO D6 Diesels. Beautiful Boat, but lately had some significant fuel issues. Unfortunately, she sits in PORT much of time as my wife is not a fan of BIG WATER, and we slip on Lake Michigan. Had some contaminated DIESEL recently either because it sat or because I got some bad stuff. Had to clean OUT RACORs for 2nd time in a year (less than 50 hours) and replace all Filters / Fuel Filters. Then had a dual engine SHUTDOWN (on Saturday, after running for 5 + hours). SB Engine alarmed and went down and then ran for about 1NM on PT and then it shut down... Tanks show I have fuel, in both Mains (1/4) and 2 Auxiliaries (3/4 full). (My configuration is 2 Main and 2 Aux tanks as been described before in Forum)... but even when I switched to AUX on the water (thinking it was mains), Engines would not start. Had to be towed in by the COAST GUARD! God Bless em! I run both sets of tanks when Out, as want to cycle Fuel.

So here is main Q- as I suspect a couple things. 1. What is and how does the FUEL transfer pump work on a diesel boat? I thought I knew and it was related to GenSet, but apparently I don't, as nothing worked. 2. I suspect I have bad sending units in tanks/or?? I do have fuel equalization in Aux tanks (under extended CockPit, just two Stopcocks) and run it open when I am on water, which I am reading I probably shouldn't do as well. Appreciate the FORUM and the assistance offered here, have searched many topics in past. THANKS in Advance!