6.0L Fuel Pump

[BryanH]

Statement???????????

The only Fuel pump I have is the HFCM. Is this correct. Or is there a second pump under the hood?

And if the first statement is true, Then does the Horizontal Module have a check valve or cut off switch to were if I had the key on #3 ON. but the motor not running the pump could cut off the fuel supply since the engine is off. I know there is a check valve on the fuel rails. But what about the Module?

[BryanH]

Not the DTRM. I know that returns fuel from the Enigne mounted fuel filter.

[03f250stroke]

i dont understand what your trying to do...there is a feed line from the tank that goes to the lift pump there in the rail, after that it sends up to the lines that connect to the fuel bowl. thats it. 2 lines feeds the left and right head, and then a return. if you want to cut power you can unplug all 3 plugs on the lift pump and that will turn the pump off.

what are you going to be doing?

[BryanH]

Originally Posted by 03f250stroke

i dont understand what your trying to do...there is a feed line from the tank that goes to the lift pump there in the rail, after that it sends up to the lines that connect to the fuel bowl. thats it. 2 lines feeds the left and right head, and then a return. if you want to cut power you can unplug all 3 plugs on the lift pump and that will turn the pump off.

what are you going to be doing?

Nothing,When I turn the key to the ON position. I am getting a loud humming noise which yesterday was not there. I understand the only fuel pump I have is rail mounted(HFCM). I was trying to find out if there is another fuel pump under the hood to check, The noise is coming from under the hood, I will pin point it tonight when I get home. I was just trying to gather info before I start. Is the DTRM a valve or pump that runs?

[03f250stroke]

obvious questions, but have you checked your filters? a humming noise? thats weird.
dtrm is inside the pump on the rail, its like a little heater for the fuel. but you wouldnt hear anything from it being its part of the rail pump i believe. umm...im a little stumped on this one.. under the hood humming sound?!?!

[07stroker]

Vacuum pump maybe. Thats what i hear sometimes under the hood buzzing

[BryanH]

Originally Posted by 03f250stroke

obvious questions, but have you checked your filters? a humming noise? thats weird.
dtrm is inside the pump on the rail, its like a little heater for the fuel. but you wouldnt hear anything from it being its part of the rail pump i believe. umm...im a little stumped on this one.. under the hood humming sound?!?!

DTRM, Is part of the Engine mounted fuel filter(Under/side), It is a return line to the HFCM which is located on the drivers rail. I just don't know if it is a valve or pump. But I'll check her out.
Thanks for the quick response. I appreciate your help. And PS. Great numbers your truck is turning.

[BryanH]

Originally Posted by 07stroker

Vacuum pump maybe. Thats what i hear sometimes under the hood buzzing

You never know, It could be anything. It sounds like a fuel pump. Times 1000%. It could be my frame mounted pump going out and just echoing to the hood. I'll figure it out.
The sound is key ON. Motor off. (Really sounds like an old fuel pump, Clogged,working overtime )

[BryanH]

OK Evan. I think I got it. Now tell me if this sounds correct.
Fuel flow = Tank---->--->-HFCM =(DTRM/H2O Separator/Fuel/ H2O-Sensor/Fuel Heater)->------->---Engine Mount Fuel filter(No Pump,Just a valve with return lines and forward lines)
---->----->--->--1)Fuel rails and 2)return to the HFCM.. So there is only 1ea pump on the fuel supply. A 100psi pump mounted in the HFCM On the frame rail..

[william_04_x]

Originally Posted by BryanH

OK Evan. I think I got it. Now tell me if this sounds correct.
Fuel flow = Tank---->--->-HFCM =(DTRM/H2O Separator/Fuel/ H2O-Sensor/Fuel Heater)->------->---Engine Mount Fuel filter(No Pump,Just a valve with return lines and forward lines)
---->----->--->--1)Fuel rails and 2)return to the HFCM.. So there is only 1ea pump on the fuel supply. A 100psi pump mounted in the HFCM On the frame rail..

you are hearing the vacuum pump under the hood i bet...it's on the passenger side fenderwell..

there is only one stock pump on the frame rail...both supply and return flow through it...on the round front cover of the HFCM is the pump plug...the WIF sensor is the lowest one on the forward end of the HFCM, right in from of the WIF drain plug...early model 6.0's have a fuel heater and the plug is on the rearward side of the HFCM...the fuel heater was deemed unneccesary and new HFCM's don't have them...the DTRM is integrated under the HFCM cover and is used for the return fuel..at certain temps it'll cycle returned fuel from the upper filter to the unfiltered side of the lower filter and back to the engine supply line...

the two lower lines on the HFCM are the supply lines, and the upper are return..

and yes, the pump is up to 100psi, but the volume at that pressure is minimal...

i just put a new HFCM on my truck last weekend...the original was getting weak....i have an ITP RR sitting in the box waiting to be installed this weekend and i'll post the results of this change when i'm done...i don't think the stock pump will be able to keep up, but i have a plan for that too..