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Running fuel from the return line instead of the main line.

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Old 04-22-2003, 03:30 PM
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Running fuel from the return line instead of the main line.

I posted before about switching from tpi to carb. Im wondering if i can put in a regular pump on the block and then run the line to the return line to get fuel from the tank. Would this work?

THANK YOU
Old 04-22-2003, 05:09 PM
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You want to suck fuel from the tank via the original return line? If that's what you're asking, it won't work. The return line just dumps fuel back to the tank. The feed line is what has the pickup and the in-tank filter on it.

You'd have to really overfill the tank to make any use of the return line!
Old 04-22-2003, 06:20 PM
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you have two options, use the electric pump and put a regulator on it and adjust it down or unplug the electric pump and simply hook the feed line up to a mech pump and suck fuel right through the old pump using it at simply a pickup and not a pump.. both methods work.. i am using my electric pump.. others have used mech.. some people have switched to mech when the fuel pump burns out because its easier then droppin the tank..
Old 04-22-2003, 08:06 PM
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So if i run it through the pump in the tank it wont mess up anything. Also to put a mechancal pump on the fuel injected block, i just have to get the pump rod and the fuel pump.
Old 04-22-2003, 09:13 PM
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Hold on ...you may not be able to pull through the old pump...I couldn"t...some can....some cant..one of those mysteries.....your choices may be a regulator or pulling the electric pump and dropping in a hose to syphon.....
Old 04-22-2003, 10:44 PM
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I went from TBI to carb and I just ran my stock pump with a regulator. The new 350 I put in my car doesnt even have a place on the block for a mechanical pump so I dont have that option anyways.
Old 04-22-2003, 11:01 PM
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Re: Running fuel from the return line instead of the main line.

Originally posted by Duke901
I posted before about switching from tpi to carb. Im wondering if i can put in a regular pump on the block and then run the line to the return line to get fuel from the tank. Would this work?

THANK YOU
thats what i am doing, and it works perfect. when i first did my engine swap i tried to pull fuel through the in-tank pump, but my carb ran out of fuel at about 4900 rpm's...makes for real slow 1/4 mile times

on my gas tank the pick up fuel line and the return fuel line are exactly the same height in the tank
Old 04-22-2003, 11:44 PM
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So i should try the return line and if that dont work then try pulling through the old pump. If that fail's then use the in tank pump and just rewire it to come on.
Old 04-23-2003, 05:42 AM
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if you use the intank pump you will need a regulator...I use the malory 3 port.. www.summitracing.com

part#MAA-4309..easiest of all sollutions.
Old 04-23-2003, 05:44 AM
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you want to run 5-7lbs of pressure..
Old 04-23-2003, 07:56 AM
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dear duke.
YES YOU CAN, also you'll notice that if you disconnect the return line it leaks inmediatelly and it will continue to do so untill your gas tank is totally empty.
i've been there, done that, just added a in-line filter, and new lines away from heat of course, and drove without any problems untill decided to use the electric pump with a pressure regulator, because my new block doesnt have mechanical fuel pump provision.
the mechanical pump WILL NOT suck fuel thru the electric pump, i've tried and belive me, your engine will die every 5 minutes.
the best to do, is (in my humble opinion) to use the return line until you get money for the pressure regulator, the guys at edelbrock told me never to exeed 6psi. on my 1406, but it seems that you can "push it" a little bit to 7.
now is up to you.
Fernando.
Old 04-23-2003, 10:07 AM
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what about using 2 pumps?....the stock tpi intank one and another elctric one, then a regulator?...
Old 04-23-2003, 11:34 AM
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Ok, i will run it through the return line. I was just worried that if the tank got to low it wouldnt be able to get fuel from the bottom of the tank, or when i turn corners to hard it would die.
THANKS FOR ALL THE HELP EVERYONE.
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