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Old 06-16-2010, 07:58 PM   #1
D-Day
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Hooking up fuel (pump) return line

How would I go about hooking up a return line to the tank? Conventional thinking suggests a sending unit with two outlets...but I have a feeling that isn't the way to do this. This is not a fuel injected setup, I just want a return line for my electric fuel pump to take the strain off of it for longer life.

Whatever it doesn't need, send it back to the tank. Keep things flowing. Anyone done this?

Last edited by D-Day; 06-16-2010 at 07:58 PM.
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Old 06-16-2010, 08:25 PM   #2
Slofarmtruck
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Re: Hooking up fuel (pump) return line

What year truck are you working on. The stock sending unit should have a supply and return. When converting to an electric pump, you would also run an aftermarket
fuel pressure regulator built for low pressure since you mention you are still running a carb. This regulator should have a return line on it. Now from what I remember, most quality aftermarket electric fuel pumps have a bypass valve inside that acts like a return which helps keep the load off the fuel pump. My aeromotive pump had this at least and I just ran a supply to my regulators, one for the nitrous and one for the carb with no return and had zero issues.

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Old 06-16-2010, 08:50 PM   #3
JMac11
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Re: Hooking up fuel (pump) return line

You CANNOT use the factory mechanical pump tank switch. I tried every variation of routing to maintain the original switch in my 84. Apparently if you put any back pressure on the switch it will bleed of into the opposing tank. Now it may have just been my switch, but I tried everything..... A recirculating system is desirable with any electric fuel pump.
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Old 06-16-2010, 10:07 PM   #4
68 TT
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Re: Hooking up fuel (pump) return line

Quote:
Originally Posted by D-Day View Post
How would I go about hooking up a return line to the tank? Conventional thinking suggests a sending unit with two outlets...but I have a feeling that isn't the way to do this. This is not a fuel injected setup, I just want a return line for my electric fuel pump to take the strain off of it for longer life.

Whatever it doesn't need, send it back to the tank. Keep things flowing. Anyone done this?
Do you have a bypass style regulator? You need one designed for this to do it right.

I have one made by Trick Flow that came with both a carburetor fuel pressure range spring and one for EFI so you can run it with either setup.

You can just plum the return line right into the top of the sending unit through a bulkhead fitting if you don't have a factory vapor return line to plumb into.
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Old 06-16-2010, 11:01 PM   #5
asphaltburner
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Re: Hooking up fuel (pump) return line

Yo! I have BOTH at the moment,...mechanical fuel pump that I run off of usually, and my e-pump setup.
Stock return line runs inside the pass. side framerail alongside the mechanical pump supply line. I have an electric Pollack six-port that switches between tanks and the e-pump supply line crosses over to the driver's side, with the e-pump mounted in it's own protective steel housng I fab'd inside the framerail nearly under the driver's seat. The e-pump supply then continues inside the framerail to the top of the radiator mounting where I mounted my pressure regulator. Return continues from the regulator across the top of the radiator to the stock return on the pass. side.
I can quick-change to the e-pump with a screwdriver, swapping the fuel tank line and carb supply line.
Todd.
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Old 06-17-2010, 09:44 AM   #6
D-Day
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Re: Hooking up fuel (pump) return line

Thanks for the advice, guys. Looks like I have another future project to tackle. Slofarm, it's a '73 crew cab; 68 TT, I think I'd have to pick one up.

Burner, that's an interesting setup. I've heard of people running both together, doesn't sound like a bad idea...cheap electric pump to get the fuel to the front without a lot of cranking, mech pump for reliability and steady pressure.
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Old 06-17-2010, 11:18 AM   #7
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Re: Hooking up fuel (pump) return line

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Originally Posted by D-Day View Post
Thanks for the advice, guys. Looks like I have another future project to tackle. Slofarm, it's a '73 crew cab; 68 TT, I think I'd have to pick one up.

Burner, that's an interesting setup. I've heard of people running both together, doesn't sound like a bad idea...cheap electric pump to get the fuel to the front without a lot of cranking, mech pump for reliability and steady pressure.
Here is the one I have on the Camaro:

http://www.summitracing.com/parts/TFS-27001/

Nice product and really nice that I can convert it to higher pressure when I convert the car to EFI down the road.

It is also vacuum / boost referenced so it boosts fuel pressure with engine demand.
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miSSed opportunity - ground up creation of an AWD 1994 454 SS that never was http://67-72chevytrucks.com/vboard/s...d.php?t=795577
69 C10 shortbed stepside 400 small block - built like what a super sport truck could have been
69 K20 lwb TBI 350 4L60E NP208 14-bolt Dana-44 w/disc
68 Camaro SS / RS 500hp 439 inch roller cam big block 4L80E
79 Malibu TPI 350 4L60 w/ Z28 steering & sway bars

Last edited by 68 TT; 06-17-2010 at 11:19 AM.
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