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Old 08-16-2006, 11:08 PM
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Default plumbing returnless fuel system?

i'm getting ready to drop in my 2002 WS6 motor and i see it's a returnless fuel setup. can i just hook up the pressure line and cap my original return or will this cause issues with the fuel system? i have a high flow walbro 255 in the car and had planned on getting the napa quick disconnect with a hose barb and some fuel injection hose but i'm afraid this won't work.

can anyone shed some light on this for me? i've just never worked with a returnless fuel system and don't know the ins and outs of it.
Old 08-16-2006, 11:18 PM
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It is not actually returnless, there is a fuel pressure regulator inside the gas tank on a 2002. So you will have to run a FPR. The easiest solution is to put in a corvette fuel filter/fuel pressure regulator. The PN should be up in the FAQ sticky. It does not matter where you mount it, it can be close to the tank or if you have a return line already running to the engine compartment you can put it there. Another way would be to run an aftermarket adjustable FPR, but that would be more expensive than the vette filter/FPR.
Old 08-16-2006, 11:29 PM
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Originally Posted by G-Body
It is not actually returnless, there is a fuel pressure regulator inside the gas tank on a 2002. So you will have to run a FPR. The easiest solution is to put in a corvette fuel filter/fuel pressure regulator. The PN should be up in the FAQ sticky. It does not matter where you mount it, it can be close to the tank or if you have a return line already running to the engine compartment you can put it there. Another way would be to run an aftermarket adjustable FPR, but that would be more expensive than the vette filter/FPR.

so the vette filter has a built in regulator? so is there an in/out fuel and then a return fitting on this contraption? i'll go check the FAQ, just figured i'd ask.

thanks.
Old 08-16-2006, 11:34 PM
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Here is a pic of the vette fuel pressure regulator.

The F-bodies like your 2002 has the fpr as part of the fuel pump assembly. The vettes used an external regulator near the tank with one line running the length of the body to the fuel rail.

Old 08-16-2006, 11:36 PM
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anyone got a part number on that? want to make sure i pick up the right part.
Old 08-16-2006, 11:45 PM
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Found it
https://ls1tech.com/forums/showthrea...sure+regulator
Old 08-17-2006, 12:20 AM
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Originally Posted by G-Body

thanks!
Old 08-17-2006, 07:25 AM
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just shopped around for this regulator & best price i found was @ TheAutoPartsStore.com. part # GF822 for $36
Old 08-17-2006, 08:32 AM
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if you dont want to run that regulator, you dont have to.

heres a tip.....
in a fluid system like the fuel system, everything between the regulator and the pump, is at the regulated pressure.

so imagine having your feed line going into the regulator and then from the regulator to the return..
now you can tap off ANYWHERE on that feed line and its at the correct pressure.

alternitvely, you can look at it this way.. feed the line straight to the fuel rail, then tap off the feed somewhere and run it to a regulator.
Old 08-17-2006, 10:21 AM
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Originally Posted by MrDude_1
if you dont want to run that regulator, you dont have to.

heres a tip.....
in a fluid system like the fuel system, everything between the regulator and the pump, is at the regulated pressure.

so imagine having your feed line going into the regulator and then from the regulator to the return..
now you can tap off ANYWHERE on that feed line and its at the correct pressure.

alternitvely, you can look at it this way.. feed the line straight to the fuel rail, then tap off the feed somewhere and run it to a regulator.
MrDude,

Normally I am in agreement with everything I have seen you post and have gotten some excellent ideas and advice from them. But in this case I can't agree. I will agree that everything after the regulator is at the regulated pressure, but between the pump and the regulator the pressure is whatever the pump is putting out, unless there is some relief from other sources. If this was not the case, why would you need a regulator at all?

If I am missing something, please provide more explanation.

Pat
Old 08-17-2006, 10:40 AM
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Originally Posted by Stu Cool
MrDude,

Normally I am in agreement with everything I have seen you post and have gotten some excellent ideas and advice from them. But in this case I can't agree. I will agree that everything after the regulator is at the regulated pressure, but between the pump and the regulator the pressure is whatever the pump is putting out, unless there is some relief from other sources. If this was not the case, why would you need a regulator at all?

If I am missing something, please provide more explanation.

Pat
Pat,

Unless it is a bypass regulator, however these are normally mounted somewhere close to the motor. I don't think that's the case with the 'Vette regulator. Anyone know for sure?

Andy1
Old 08-17-2006, 11:01 AM
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Originally Posted by Stu Cool
MrDude,

Normally I am in agreement with everything I have seen you post and have gotten some excellent ideas and advice from them. But in this case I can't agree. I will agree that everything after the regulator is at the regulated pressure, but between the pump and the regulator the pressure is whatever the pump is putting out, unless there is some relief from other sources. If this was not the case, why would you need a regulator at all?

If I am missing something, please provide more explanation.

Pat
i think i did a bad job of explaining it.. i have to leave in 5mins for a meeting, and i donno if i'll be back on tonight, so excuse the PSpaint drawing and the short description:


the blue line is regulated pressure. the yellow is just the return, not under any specific pressure.

the fuel rails can connect anywhere in the blue. they can be tapped off, or they can be part of the link (aka, fuel goes thru the rails, back out, then to the regulator.)

the regulator is whats setting the pressure, by only letting fuel out the yellow line when the pressure his higher then the setting...


the vette fuel regulator works the same way as any other aftermarket return regulator... its has a tap off of it that is the return line... basiclly its straight thru filter, with a T in it.. and a regulator that is open to atmospheric pressure on the return.. make sense? i hope so.. i gtg
Attached Thumbnails plumbing returnless fuel system?-fuel-system.jpg  
Old 08-17-2006, 05:47 PM
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I have a 99+ 'Vette Regulator located near my tank. It has 3 fittings, using the attached picture, based on yours, the blue line is input from the tank and will have whatever pressure the pump can deliver, unregulated. The red line is regulated, 58 psi I believe, and goes forward to the fuel rail. Mine is a single fuel line rail. The yellow line is the return line to the tank and is open to atmospheric pressure as you stated, and any fuel that exceeds the demand from the red line goes down the yellow line to the tank.

At least that is how I understand it.

Pat
Attached Thumbnails plumbing returnless fuel system?-fuel-system-1.jpg  
Old 08-17-2006, 06:28 PM
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Default Vette Regulator/Filter

The end with one 3/8 opening is the regulated line to the engine. The end with two fittings the 3/8 is un-reulated pressure from the pump. The 5/16 line is the over pressure relief back to the tank, so mount it close to the tank and you only have to run a short line.
Jim
Old 08-17-2006, 09:25 PM
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If the regulator is a part of the pump like a 2002 f-body, how would you route the fuel line with an inline fiter and a single line to the engine? Could you still use the corvette filter/regulator? Any help would be great. Thanks John L
Old 08-17-2006, 10:30 PM
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Originally Posted by lechner80
If the regulator is a part of the pump like a 2002 f-body, how would you route the fuel line with an inline fiter and a single line to the engine? Could you still use the corvette filter/regulator? Any help would be great. Thanks John L
The regulator on an f-body is part of the fuel pump assembly, it is actually just above the pump on the sending unit in the fuel tank. If you want to use the f-body sending unit assembly and graft it into your tank you can. The f-body sending unit assembly has a fuel "bucket" and a venturi system to keep that bucket full so you can run it in any tank because it does not need baffles. Heres a link showing how someone grafted it into their tankhttp://www.cardomain.com/ride/716267/3
Anyway back to your question if you use the whole assembly you can run a single line to the engine and you do not need the vette filter regulator combo. You can use any EFI fuel filter (must be able to withstand 60+ PSI), I would use a fuel filter for a 99 5.7L camaro you can get them just about anywhere for under $10
Old 08-17-2006, 10:56 PM
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i'm in agreement with MRDude on the regulator description. there are only 2 sides to a system regulated by a bypass regulator; the pump side which is regulated pressure and the return side which is free flowing back to the tank.
Old 08-18-2006, 08:52 AM
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don't mean to hijack, but i have a related question

i'd like to used the vette regulator to avoid running a return line to the engine

however, i have a regulator on the fuel rail (04.5.3L engine). is there some way to use what i have w/o replacing fuel rails & regulator?
Old 08-18-2006, 09:03 AM
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Originally Posted by Stu Cool
I have a 99+ 'Vette Regulator located near my tank. It has 3 fittings, using the attached picture, based on yours, the blue line is input from the tank and will have whatever pressure the pump can deliver, unregulated. The red line is regulated, 58 psi I believe, and goes forward to the fuel rail. Mine is a single fuel line rail. The yellow line is the return line to the tank and is open to atmospheric pressure as you stated, and any fuel that exceeds the demand from the red line goes down the yellow line to the tank.

At least that is how I understand it.

Pat
thats not quite how it is.. but you're only missing one small part.

see, in your pic, you have the assumpsion that the regulator has a in and a out for a pressure side... really, the center of it is open.. its all the same area.


the only special port on a regulator is the return port... its covered by a spring loaded valve. when the pressure is high enough, this valve opens, returning some fuel, and keeping the rest of the pressure constant for the system.
im showing this in the first pic by showing that its straight thru.. (the line is dotted to show its inside the regulator)



in the second pic, i show a blowup of a filter/regulator.
excuse the poor drawing, but heres the basics... the pump continuesly pumps fuel into the lines.... the pressure would keep going higher, except that once it exceeds a set amount the spring opens, and fluid goes by... the more extra the pump flows, the more it opens.... thereby regulating the max pressure of the system.




in the third pic, we see how the Fbody is laid out.. some fuel returns Via a T (this is visible under the car...) and the regulator is inside the gas tank..



in the final pic i have below, this is something i posted a long time ago, but its a better pic of a regulator... i got it from this thread:
https://ls1tech.com/forums/showthrea...regulator+fuel

edit:
btw, in the pic below, red = regulated fuel pressure and blue is the return....

Attached Thumbnails plumbing returnless fuel system?-fs1.jpg   plumbing returnless fuel system?-fs2.jpg   plumbing returnless fuel system?-fs3.jpg  
Old 08-18-2006, 09:04 AM
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btw, i should note, on the Fbody one, it doesnt flow into the main area of the tank.. rather, it flows into this "bucket" that the pump is inside... its a neat setup, but unrelated to the topic at hand.


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