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Discussion Starter #1
Anyone out there converted to a Mechanical Returnless Fuel System just by replacing the fuel pickup assembly?

My current Zetec Setup has the electronic returnless fuel system. Pain in the ass when running an aftermarket engine management system. However, I have found out that I am actually quite lucky in the fact that the V6 Escape/Tribute came with a mechanical RFS and it drops right into my fuel tank in place of the electronically controlled pump.

Just wondering if anyone else made a switch to a MRFS vs taking all the time and effort to do a return fuel system?

I am also planning on replacing the stock V6 pump with a Walbro 255lph constant 12v pump that I happen to have left from another build. Anyone know what the stock pump flow rates are?
 

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Took care of the "New Thread" Sleepy.

Now I'm wondering just how this system works, pressure regulator & return as part of the in-tank unit?
 

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Discussion Starter #4
Took care of the "New Thread" Sleepy.

Now I'm wondering just how this system works, pressure regulator & return as part of the in-tank unit?
Thank you for making this a new thread.

Yes! The pickup housing and fuel pump assembly also incorporates an in tank fuel pressure regulator and return line. The pump runs at a constant 12v and simply circulates the fuel inside the tank until it is needed at the injectors/fuel rail.

The V6 pumps are of a constant voltage type so there is no worry of the pump burning out. The constant flow of fuel through the pump cools it. Also there is no hot fuel circulating back from the fuel rail.

I realize that it isn't the setup for someone that wants an adjustable fuel pressure regulator. As far as I am concerned, 38-55psi is more than enough for most street builds using modern injectors. That is including forced induction builds. I would consider maintaining flow at XX-PSI to be of more of a concern. So you simply add a larger flowing constant 12v pump, something like a Bosch or Walbro with the lph flow required for your setup.
 

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Been wondering when Ford would trip over that idea since they have been almost doing it for a while now. The original bypasses a lot of fuel right there on the spot as well. The return simply dumps into the can to keep it full. I myself think slowing the pump down is harder on them, it should be full speed all the time.
 

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Discussion Starter #6
I couldn't agree more!



So the fuel pump arrived last week and I spent some time this weekend retrofitting it.

Stock V6 pump on the right and my new 255lph on the left.


Easy to see that it will require some modification. Again there is probably a pump that will fit directly, this just happens to be a pump I have left over from another build.

So here goes....

Stock top plate and pump retaining hole height!


After a quick hit with a grinder and file....


The longer pump now sits perfectly in the bucket.

The new pump also has a bit longer sock on it..... it does fit in the bucket without issue.


Of course the wiring connectors couldn't be the same....

in this case it is probably good that I took it apart. Looks as though the stock one may have gotten a bit hot at some point.


Probably why I got it for so cheap [;)]

The new one is much beefier.


A few quick solder joints


and voila....


Still waiting on my engine to return from the machine shop.... Once I have this system up and running I will update. Just an FYI, This pump setup will be running an 8 injector, 2 stage, fully sequential fuel injection.
 

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whaaa? on a zetec? thats crazy talk!
 

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You DO like to experiment...
 

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