Hi there

I have a set of aftermarket 1/2 " EFI fuel rails for my car that I woiuld like to install.

Im not quite sure how to go about hooking up the feed and return lines.

Both ends on both rails have a 1/2 " pipe thread in them, and the rail for the drivers side has an 3/8" outlet pointing down between # 6+7 injectors. This outlet is designed to be a return, but I was told this would be a bad

idea because it could some what starve injectors 5+6 for fuel.

Now I will mention that The front of the fuel rail on the drivers side has to remain plugged. There is no way to get any kind of fitting or 90 degree elbow here because of the distributor.


Here is how I thought of doing it. ( All feed lines will be -8 and return will be -6)

1.) Intall a T fitting in the back of the passenger side fuel rail.

2) Run the feed line to the T fitting in the passenger side fuel rail

3) Run a short line from the T fitting on the passenger side fuel rail over to the driver side fuel rail and use a 90 degree to hook it up.

( this way would have both fuel rails fed from the rear)

4) I would then hook up 1 return line to the front of the passenger side fuel rail, and then run it to my pressure regulator


This is the only way I could think of doing it while having a good supply of fuel to both rails. I would rather take the return of both rails, but I dont think its proper to

bleed of the return half way up the fuel rail.

Will it be ok just taking the return of one fuel rail??

The pressure should equalize between the 2 rails at the T fitting on the feed side.

I hope this doesn't sound to complicated.

Thanks

 

You won't be starving 5 and 6, unless something goes catastrophically wrong...and, at that point, 5 and 6 are probably the least of your worries.

Returnless fuel systems are dead-headed at the front cylinders, and they work just fine. By comparison, 5 and 6 will also be dead-headed. You really need to be flowing some fuel through those injectors to drain 4" worth of 1/2" ID fuel rail.

For best results, split the feed hose to 2 smaller hoses that feed the back of the rails (like you described). I'd run hoses from the front of the rails together, then to the regulator. You can run them into a Y fitting with a single hose going to the regulator, or run them separately to 2 inlet ports on the regulator, then the single regulator return to the tank.

Scroll about 1/3 of the way down for my pics:

https://www.theturboforums.com/smf/index.php?topic=34314.200

Mark

 

Feeding the rails from the rear wont be a problem.

Do you think it will be a problem having only the one return line running off the front of the passenger side fuel rail?????

I know it would be ideal to drain the returns right off the front of both rails, but I just dont like the idea of draining the one rail right in the middle.

It would still maintain proper pressure in both rails by doing it this way.

Unless there is some unknown reason why you should'nt only drain one side off???????

Thanks for the Imput

 

Heck, you could probably just run both rails dead-headed and save yourself some headaches. Run the -8 hose from the pump to the front, then hook it to a regulator inlet. Run the regulator return line out the bottom and back to the tank (-4 or -6). Take the regulator outlet hose (-8) and split it to a pair of -6 feed lines, and run them into the back of the rails. Plug the front and middle of the rails.

Someone once told me that this system won't work, but it's pretty much identical to how the returnless cars do it (substitute a physical regulator for a pump speed controller). But, I checked with a couple of egghead engineering buddies, and they saw nothing wrong with it, as long as the rails are big enough (and 1/2" ID qualifies for big enough).

Mark

 

Or what about just running the -8 line directly to the back of the rails like I had talked about with the T and everything else.

My feed line runs right past my regulator.

Would there be anything wrong with putting a T into the feed line where it goes by the pressure regulator and then running a -6 line from the T to the regulator.

This would bleed off the pressure before it even gets to the rails.

It would really simplfy everything.

Thanks Again

 

I just followed Aeromotive's suggestion. I came from the y-block to the front of the rails using 180* fittings. I then 90* out of the back of the rails into both side of the regulator.

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Here's an old .pdf diagram of what I'm talking about, with the dead-headed rails. Nice and simple. Ignore the notes about the Schrader valve and fuel pressure sensor...those apply to the stock 2004 Cobra fuel rails that I was originally going to use until I got a pair of CPR rails for this 2004 Cobra engine.

Mark

 

Did I accidentally miss something? His avatar and sig say he has a fox. Why is everyone talking about returnless later model systems?

 

I was going to run 2004 Cobra returnless-style rails on my return-style fuel system on the 2004 Cobra engine in my 1994 GT. It was going to be a dead-headed system, but the overall style can easily be used for what he's talking about, if he just plugs the 2 front and 1 center return fittings on his rails.

Mark

 

Check out that .pdf file that I uploaded a couple of posts ago.

Mark

 

So do you think I could put a T into the feed line before it gets to the fuel rails and run a -6 line from the t to the regulator???????

 

I just don't understand why someone would want to install a returnless style fuel system on a vehicle that already is setup for a return line.

 

Reread my posts...I'm not telling him to build a returnless system.

Mark

 

Post a schematic sketch so I understand what you're talking about.

Mark

 

Pardon my shitty Diagram , but hopefully you can figure it out
as you can see I want to tap into the main line before the fuel rails, which would would do the same thing as taking it off the rails.

The way I see it your just trying to bleed off pressure any were in the pressurized system to maintain a regulated pressure.

Mabye Im wrong but I dont see any problem doing it this way.


T Fitting Main Line Fuel Rails
-------------------------------------------------------------------------------------------------------
I I I
I I I
I I I
I I I
OOO I I
OOO Regulator I I
OOO I I
I
I
I
I Line back to tank
I

 

It might work, but I'd just skip that T and run it into the regulator per my diagram. If you're using a universal aftermarket regulator, then you should have enough fittings on it that you can do it per the diagram.

Mark

 

My setup is nearly identical to the way Mark's diagram is written except with 2 pumps and 2 feed lines to the regulator.


Fuel cell (2 -10AN outlets) -> 2 A1000 pumps (pre filter/post filter assemblies) -> 2 -8 AN lines to an A13110 Pro series regulator -> 2 -8AN lines to each rail (plugged at the rear) and 1 -8AN return line.

 

IMO, I would just return of the driver side rail in the middle before I would deadhead the rail. That being said, if you want to take the driver side rail, cut the end of the rail at a 45 degree angle and tig weld on a -6 fitting on the end and it will clear the distributor just fine. The Behind Bars fuel rails are made in a similar fashion.

Chris

 

I came in the back and Y'd into each rail then came out the front thru the reg. as a rerturn.
http://jakesperformancefabrication.com/gallery/v/6654/Sho-Pny_s Mustang 014.jpg.html

 

Same here. Except I came into the front of the rails first and returned out the back.