6.7 fuel pump on 7.3.

campbellflage · Aug 8, 2015

Ron's Power Stroke said:
the way i read it the 6.7 EF feeds a HP injector pump..the return is at the feed side of the HP pump not the EFP.the 7.3 does not have a HP injector pump to return from..instead we return from the bowl or regulator..

So your thinking there is 2 return lines one from the hp pump and another from the whatever the engine doesnt use in the 6.7?

Ron's Power Stroke · Aug 9, 2015

that is how i read it... Fuel that is returned from the fuel rail combines with fuel being returned from the high-pressure fuel injection pump and passes through the frame mounted fuel cooler to the diesel fuel conditioning module.

campbellflage · Aug 9, 2015

Ok but isn't the diesel fuel conditioning module on the return side of the pump? Thats how i understand it, depending on its temp it either goes back to the tank or rerouted back to the engine through the filter on the pump?

dsberman94 · Aug 9, 2015

No. Read the red words. It says based on the fuel temp it either routes it through the conditioning module or straight to the tank. Not sure that means going back to the engine. I'm thinking it just bypasses a part of the filter portion and will go straight to the tank. You're the one with the pump sitting on a bench somewhere, check the thing out and see how it works so we can all stop guessing.

campbellflage · Aug 9, 2015

dsberman94 said:
No. Read the red words. It says based on the fuel temp it either routes it through the conditioning module or straight to the tank. Not sure that means going back to the engine. I'm thinking it just bypasses a part of the filter portion and will go straight to the tank. You're the one with the pump sitting on a bench somewhere, check the thing out and see how it works so we can all stop guessing.

Maybe we are not understanding each other, the DFCM is the fuel pump itself, so yes fuel is sent back from 2 different places on the 6.7 back the the DFCM and depending upon heat either sent down into the pump or back to the tank, where are we lost here thats what i have been saying.

dsberman94 · Aug 9, 2015

But why would the conditioning module be on the return side when you want the water out of the system before it gets to the hp side of things. As far as I'm understanding the conditioning is what removes the water from the fuel?

I'm actually not understanding what temperature has to do with it actually.

Ron's Power Stroke · Aug 9, 2015

:whs:

i believe its the water separator filter

campbellflage · Aug 9, 2015

dsberman94 said:
But why would the conditioning module be on the return side when you want the water out of the system before it gets to the hp side of things. As far as I'm understanding the conditioning is what removes the water from the fuel?

I'm actually not understanding what temperature has to do with it actually.

The DCfm has 2 inlet 2 outlet, so feed and return, return an go back through the water separator or back to the tank, if their was no temp regulation and it just kept looping back to the engine could you imagine how hot that would get, at least if it goes back to the tank it mixes with more diesel and cools down a little.

mandkole · Aug 9, 2015

In normal operating conditions (low demand, low temps) the system would operate as a continuous loop going between the LP pump, HP pump, injs. In events of very high return fuel heat (by product of high demand, engine heat rejection, heat caused by pressure), the fuel is sent back to the tank where its mixed to cool. In real cold temps, the circulation loop would be beneficial, avoiding this hot/cold fuel mix can eliminate tank condensation and water production as well.

We (7.3 guys) would greatly abbreviate some of the functions on this system. As we would use it, it looks like it would function similarly to an airdog with water separator functions.

campbellflage · Aug 9, 2015

mandkole said:
In normal operating conditions (low demand, low temps) the system would operate as a continuous loop going between the LP pump, HP pump, injs. In events of very high return fuel heat (by product of high demand, engine heat rejection, heat caused by pressure), the fuel is sent back to the tank where its mixed to cool. In real cold temps, the circulation loop would be beneficial, avoiding this hot/cold fuel mix can eliminate tank condensation and water production as well.

We (7.3 guys) would greatly abbreviate some of the functions on this system. As we would use it, it looks like it would function similarly to an airdog with water separator functions.

What he said.

Ron's Power Stroke · Aug 9, 2015

too complicated for a 7.3 IMO..we don't pressurize fuel like a 6.7 so the only way for it to heat is fuel sitting in the bowl with the engine cover closing it in or by fuel passing though the heads with a RR...test has proven with a full RR and full tank of fuel that even in Florida/AZ heat, the temps do not rise enough to make a change.. by the time fuel gets close to being hot in a 7.3 its time to refuel anyways..
also have to think, the hotter the fuel is when going into the cold tank,the more condensation you will make..

dsberman94 · Aug 9, 2015

Only reasons I wanted this pump originally was for the amount of fuel flow and the water separator. I'd have an issue with using an air to air fuel cooler up here in the winter. I'd have instant fuel gel in it when it reaches 0* outside in the winter.

campbellflage · Aug 9, 2015

This truck has a reg return, even if it circulates closed loop, until the fuel gets hot enough to go back to the tank, who cares it's not hindering performance and would be a benefit I would think, can run huge injectors with what might be basically a double feed pump (tank pickup, and return side loop). Either way, I'll post up how it goes, maybe toss in a temp sensor tied into the cts for measurements

campbellflage · Aug 9, 2015

dsberman94 said:
Only reasons I wanted this pump originally was for the amount of fuel flow and the water separator. I'd have an issue with using an air to air fuel cooler up here in the winter. I'd have instant fuel gel in it when it reaches 0* outside in the winter.

I can understand that, down here lowest temps are in the 30s, will I benefit from it, probably not, but it's not gonna hurt adding a cooler either.