LS Engine fuel feed system
 

I have a 2006 4.8 ls engine and it only has one line at the fuel rails, the feed line. There is no return line nor is there a regulator. See below.

So I understand the factory fuel pump has the regulator, filter and pump all in one unit. Below is an airtex E3609M. Which is like an OEM replacement.

So if the OEM pump has the regulator, filter and pump all together, why are there return lines in the top?


http://farm5.static.flickr.com/4118/...ac7a06ec21.jpg


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Re: LS Engine fuel feed system
 

I'd have to go crawl under a truck to tell you for sure, but I'm pretty sure those extra outlets just connect to the charcoal canister in front of the tank.

Re: LS Engine fuel feed system
 

GM swapped from a return type, to a returnless fuel system in '04 I think.

Re: LS Engine fuel feed system
 

Too much emissions when pumping the fuel up to the hot engine, then back to the tank :agree:

And I'm going to run a Corvette style filter/pressure regulator in front of a Walbro 255 inline pump, with an Earls 70micron filter between the pump and the tank. All plumbed with -6AN Aeroquip socketless hose.

And I bought an Earl's -6AN bulkhead fitting to attach to the stock sending unit for a return.

Re: LS Engine fuel feed system
 

Oh yeah I forgot about the EVAP system... My brother in law has an 05 I'll check it out some time.

I want to go with an in tank pump but if I can't figure this out I'll probably also go with the corvette filter/regulator.

Re: LS Engine fuel feed system
 

Hey thanks this stuff looks nice. No bulky hose clamps! Sorry never heard of it. I mean I've seen it but I never knew what it was called. Is it easy to install the hose over the barbed fittings? I guess this is how it's done?

Umm I don't think I follow... do you have a picture or link?

Re: LS Engine fuel feed system
 

Yeah, you just push the fitting onto the hose. It's NOT easy :) But it isn't coming off either. The stuff is tough as nails, and nice to work with once the hose ends are on. You have to make sure you get the right stuff. Some of it is not as good for heat as others, I'm looking up some info on it now.

My factory tank does not have a return line, so I bought an Earl's bulkhead 90 deg. fitting. I will take out the stock sending unit, and drill a hole through the top, next to the outlet pipe. Then I'll put the bulkhead fitting down in there, and tighten it up with 2 nuts, and attach a piece of hose along-side the factory output line down into the tank. Then I'll have a return line in my factory tank.

Re: LS Engine fuel feed system
 

After looking at my 4 yr old aeroquip socketless hose today, I can't recommend it anymore! It's not holding up. I'll be using 3/8 steel with AN adapter fittings.

Re: LS Engine fuel feed system
 

good to know....

Re: LS Engine fuel feed system
 

So what's it doing? Cracking?

Re: LS Engine fuel feed system
 

***EDIT - I thought I would put the edit bold so everyone knew I was tarded! It never occurred to me that this was something other than a 73-87! :haha: So if anyone saw this before I deleted it, know you know where my brain was!

I'm gonna go look at your build thread, then I'll be back.

*** Edit again - OK, I'm back. What kind of fuel tank will you be using? The original, or something different?

Re: LS Engine fuel feed system
 

Yep! I guess it works good if you want to replace it every 5 years :lol:

Re: LS Engine fuel feed system
 

Well I'm thinking about going with the early classic 23 gallon #911-SFFI. It's so expensive though.

Re: LS Engine fuel feed system
 

I would get in touch with fuelcellguy and have him build you a tank I'm sure he can destroy that price from early classic. heres a link to his website. http://www.aluminumfuelcell.com/index.html

Re: LS Engine fuel feed system
 

try david boyd welding, also you dont really HAVE to buy the fuel injected tank, you can just get one to fit your truck for almost half of the FI tank cost. put the pump on the outside along the frame rail.

www.boydwelding.com

Tell him your on the board.

Re: LS Engine fuel feed system
 

What pump did you use?


So anybody seen a fuel tank where you don't have to move frame members around, can keep the spare tire location, and have a receiver hitch? Wishful thinking?

Guess I could try to do side saddle tanks.

Re: LS Engine fuel feed system
 

I was going to suggest fuelcellguy too.

You could also use a 25 gallon tank from an 87 TBI Suburban, and use an OEM in-tank pump sending unit. That tank and sending unit setup can be found fairly cheap on the board's classified section, or a junkyard.

Even new, those tanks are under $100, a new sending unit is less than $70, pump is about $68, and the filter/regulator is $35. Complete setup for under $300, brand new.

Re: LS Engine fuel feed system
 

Can't speak for him, but I'm using a Walbro 255 inline pump.

Re: LS Engine fuel feed system
 

I used a Pierburg pump form Turnkey engine supply

http://www.turnkeyenginesupply.com/e...at=1&key=parts