More Fuel Pump talk.
SOME 2011-2012 F-SUPERDUTY VEHICLES EQUIPPED WITH A 6.7L DIESEL ENGINE MAYEXHIBIT A SLIGHT VIBRATION AND/OR BUZZING OR GROWLING-TYPE NOISE FROM THE DFCM AT TIMES WHEN OPERATING WITH THE FUEL TANK AT 1/4 LEVEL OR BELOW. THIS CONCERN SHOULD BE CONSIDERED A NORMAL CHARACTERISTIC AND IS DUE TO A SLIGHT AMOUNT OF AIR WHICH MAY ENTER THE FUEL SYSTEM DURING LOWER FUEL LEVEL CONDITIONS. NO REPAIRS SHOULD BE ATTEMPTED. FUEL SYSTEM AND VEHICLE DURABILITY, AS WELL AS VEHICLE DRIVEABILITY AND FUEL RANGE, ARE NOT AFFECTED
<!--EFFECTIVE DATE: 12/09/2011-->EFFECTIVE DATE: 09-DECEMBER-2011"
I don't know about the rest of you but I don't want any air introduced in my fuel. I had a situation with my 08 that after driving into campground with about 1/8 tank and running fine it would not re-start next day. Later with my AutoEnguinity software I determined I had a low fuel pressure code. Cycled key several times as if one changed fuel filters following draining HFCM to check for water (none); it started and ran fine. Ford has had same design on tank for some time. I try to keep it above 1/4 tank.
https://www.ford-trucks.com/forums/8...d-for-3-a.html
Pictures in link above...... I did not make the mods in that link; good picture of the device that can allow the air to infiltrate your fuel when the level drops below same.
Bob








