Mystic96

The motor I will be using is a '99 model LS1 from a Trans Am, which is a NON-return style system correct?

My '96 Cobra has a return style fuel system.

I plan on using my factory Ford fuel system up to the motor, where I plan on using -AN fittings and braided fuel lines to hook the stock Ford hard lines to the LS1 fuel rails.

Couple questions though...

I have the entire fuel system from the donor car. Fuel tank, lines, even the filter. If the LS1 car is a NON-return style system, then why are there 2 lines from the rail, 2 lines running the length of the car, and 2 lines from the tank?

What would I have to do to make the LS1 work with a return style fuel system? Would I need custom fuel rails or some 97-98 Vette rails to do this?

Just looking for some insight as to what others may have done to get past this issue.

MrDude_1

iTrader: (4)

on a return style system, everything between the fuel pump and the regulator, is at that set pressure.

you can always run a return style system, and then just have the returnless LS1 fuelrail connected to the pressure side of the regulator.

this is just like all the GM "returnless" systems...

qwickie 30sec MSpaint:

MrDude_1

iTrader: (4)

correct.

i bet one of the lines you're looking at is the vapor purge.



"return style" is really a matter of labeling...
no EFI system that i know of actually deadheads... theres always a return.
its just that sometimes the return is in the tank.. or in the back of the car.

take my fuel system for example..

fuel goes from the pump into the regulator. the regulator is in the REAR of the car... from there, one line goes back to the tank as a return, and the other goes to the front.
only one line goes to the front... and its considered a non-return style system, because the fuel rails deadend.... but there is a return.


now imagine the same system, but with the regulator up front.... is it a return style or not?



when it comes down to it, people only consider it a return style if fuel is constantly flowing thru the rails, back to the tank.... the excess fuel always goes back, its just a question of "does it go thru the rails before it heads back?"



what most 3rdgen and other stock EFI guys do is put a regulator near the front of the car... the feed and return lines are already there.. you just plumb one line to the engine and thats it...

Mystic96

Then where does the other line from the LS1 fuel rails go to?

And what do I do with my custom painted 97/98 Fuel Rail Covers with 2 holes for fuel lines?

MrDude_1

iTrader: (4)

if you have return style fuel rails..... then you have two connectors on them.

fuel goes in one, and out the other...

otherwise, you just have one... ive only worked on Fbodys, so im only fimilar with the "returnless" fuelrails...

but if you have two holes in the FRCs, dont worry, you need that second hole for the vapor purge.....

Mystic96

So is that where the other line coming off of my LS1 fuel line go to? The Vapor Purge? What is that?

I planned on having 2 braided lines coming out of the fuel rail covers, like they are on 97/98 Vettes.

crainholio

iTrader: (2)

If your fuel *RAIL* has two fittings, you somehow got a '97-98 Vette *RAIL* that has an integrated pressure regulator and a return.

If your fuel *RAIL* has one fitting, and there's a little valve mounted near the *RAIL* but not directly attached to it, that's your fuel vapor purge.

Mystic96

Took a good long hard look today at everything.

There are 2 "lines" coming off the motor, but only one comes from the actual fuel rail. The other is for the Vapor Purge or whatever. There are 3 lines that come out of the stock F-Body tank...one goes into the charcoal canister, the other two run the length of the car, but only one provides fuel to the rails.

Thats all fine and dandy, but I'm still trying to figure how to make the LS1 a return style system to work with my factory Ford fuel lines.

Basically, how do I get 2 lines from my factory hard lines on the car to the fuel rails on the motor.

crainholio

iTrader: (2)

MrDude already answered this above, but here are pics if it helps:

http://www.warpten.com/carpics/ls1_0214/DSC00038.JPG

http://www.warpten.com/carpics/ls1_0214/DSC00041.JPG

I mounted an Aeromotive regulator to my fender. The chassis hardlines both attach to the regulator as the feed and return. The 3rd port on the regulator is output to the '01 fuel rail.

MrDude_1

iTrader: (4)

heres the same thing i was saying above... only with a more detailed regulator pic.


basicly everything thats red (and everything that taps into somthing thats red) is at the LS1s regulated pressure.


everything thats blue, is the return, no set pressure.

the feed and return lines could be ANY feed and return lines from ANY car that has a EFI fuel pump.

L-EATER

iTrader: (2)

You are making this too hard. Get a 97-98 Vette fuel rail and regulator (got mine from Scoggin Dickey>>>>>>) Dont forget to get the snap ring that holds the regulator to the rail-it does not come with the reg or the rail (unless you can find a used one already assembled)

Hook the big line on the car to the big line on the Vette fuel rail and the smaller line on the car to the smaller line on the rail. Pure choice motorsports can fix you up with the adapters necessary to hook it all up.

MrDude_1

iTrader: (4)

thats the other option..

honestly its not hard either way.. just pick a way to do it, (either aftermarket regulator, or replacement fuel rail) and go with it.