Fuel return diy

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projectmidnight74

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Great evening to the gurus of this great forum.
I am in the final stages of finishing up on this project. One of my last 2 missions is to resolve the vapor lock. I plan to purchase the WIC 33040 fuel filter with extra output for return..my thoughts are to route that return to the tank area and create a snug brass fitting on the rubber portion of the vent line.
Good idea or bad idea. I am attaching a pic.
 

projectmidnight74

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Pic of tank and fill line and vent line beside it.
 

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nvrenuf

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I really think the brass fitting in the hose will leak.

Find a piece of tubing the correct size, put a nipple in the side and splice it in to the vent hose.

I think someone actually makes a tube like I described but I can’t remember who it was.
 

75gmck25

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You could also just change your sending unit to one with 3 ports. My ‘75 already had one, and when I replaced it I found they were stocked at some AutoZone stores. I don’t recall the price.
 

Robert Bare

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First, are you sure it's vapor lock? Try running it without the gas cap.
I doubt the filter/return will help. How do I know? Because I have a 401 jeep J10, used to haul a camper in it. But, even without the camper, still can do it..did about 2 months ago, hauling wood pellets home. This has the original tank(tiny) up front, then a big one I added years ago, where the spare tire used to hang. Out here, lots of ethanol "winter fuel" most the year. Running ethanol free really helps, but is expensive.
So, years ago, what I did was wrap all the lines in insulation and aluminum foil, from pump to tank.
Yep that helped quite a bit.
What "cured" it?? Added a pusher pump, back along the frame.When it starts to die, staring for fuel, I reach down and turn on the switch and turn pump on. In a few seconds, zoom, off we go!
And this jeep does not even have A/C!
Added the pump probably about 20-25 years ago, for this problem. Most of the small electric pumps have light poppet valves, so even when off the regular fuel pump will draw fuel through them. Easy to check, just suck on one. BUT, have put others on customers trucks, and they just let them run all the time.
OK, that's my 2 cents, and experiences.
 

projectmidnight74

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So, I have a file pressure regulator that has the ports but I had to use one to add a gauge to it so I can actually know what my fuel pressure was. I can see the fuel bubbling on the filter after hard drives at **** off. I can also see the blue smoke and it smells like fuel sometimes at idle. It doesn't always do it, but I'm my thought process, when the bowls get full on the Edelbrock it has nowhere to go so it becomes rich and begins to flood. I'm only running 5.5 psi to the carb from a 7psi electric pump so what left needs to go somewhere.
 

projectmidnight74

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You could also just change your sending unit to one with 3 ports. My ‘75 already had one, and when I replaced it I found they were stocked at some AutoZone stores. I don’t recall the price.
I just don't want to stop that tank a 3rd time. It sucks lol
 

Tonimus

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If you're only running 5.5psi and the fuel pump is "overpowering" the needle and seat, causing a rich condition, that would also prevent vaporlock. It's more likely that you smell fuel because the burning oil has soiled a spark plug and a cylinder is missfiring. Thus fuel down the exhaust.

If it's just burning oil, it's either valve stem seals, intake seals or sucking in through the PCV. Could also be a cracked head, but far less likely.
 

projectmidnight74

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If you're only running 5.5psi and the fuel pump is "overpowering" the needle and seat, causing a rich condition, that would also prevent vaporlock. It's more likely that you smell fuel because the burning oil has soiled a spark plug and a cylinder is missfiring. Thus fuel down the exhaust.

If it's just burning oil, it's either valve stem seals, intake seals or sucking in through the PCV. Could also be a cracked head, but far less likely.
How do you feel about adding a catch can?
 

ali_c20

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I run oil catch cans on my trucks. I was surprised how much oil and whatever they catch. It is definetely a good add on and you can check how much oil is drawn through the pcv. For a system with return I would go the route with a 3 port sending unit, move the pressure gauge to the fuel line with a gauge inline fitting. Use the return port for return. I never do sketchy things on fuel systems and use quality parts cause I don't want to burn down my rides or die in a fireball. My 0,02$
 

Tonimus

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For fuel, there's no issue running a 3 or 4 port regulator at the carb. The Holley 12-887 is a bypass regulator with an extra port for a gauge.

I've got a catch can on my Camaro and my buddy's '63 Nova. They work great. https://www.amazon.com/dp/B081N392BN/
 

Bextreme04

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So, I have a file pressure regulator that has the ports but I had to use one to add a gauge to it so I can actually know what my fuel pressure was. I can see the fuel bubbling on the filter after hard drives at **** off. I can also see the blue smoke and it smells like fuel sometimes at idle. It doesn't always do it, but I'm my thought process, when the bowls get full on the Edelbrock it has nowhere to go so it becomes rich and begins to flood. I'm only running 5.5 psi to the carb from a 7psi electric pump so what left needs to go somewhere.
What kind of pump? Vapor lock is almost impossible with an electric pump and is solved by moving the pump closer to the tank.. but you should definitely be using a return line system with an electric pump. Vapor lock is when the fuel in the fuel line before the pump gets hot enough to vaporize under vacuum as the mechanical pump is trying to pull the fuel up from the tank, you flow a much greater volume of fuel through the system when it has a return line, so it keeps the heat lower in the line. Electric pumps are designed to PUSH fuel and should be mounted as low and as close to the tank as possible. Why are you using an electric pump to begin with?
 

projectmidnight74

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What kind of pump? Vapor lock is almost impossible with an electric pump and is solved by moving the pump closer to the tank.. but you should definitely be using a return line system with an electric pump. Vapor lock is when the fuel in the fuel line before the pump gets hot enough to vaporize under vacuum as the mechanical pump is trying to pull the fuel up from the tank, you flow a much greater volume of fuel through the system when it has a return line, so it keeps the heat lower in the line. Electric pumps are designed to PUSH fuel and should be mounted as low and as close to the tank as possible. Why are you using an electric pump to begin with?
This was my bright idea thinking it was more efficient. Pump is mounted on the frame rail down by the tank. I can see it bubbling in the clear filter when parked after running if I'm on it hard, and that fuel has not return so its just sitting there. I notice also when driving and cruising after a while, it gets a little boggy when I hit the throttle as if its flooding, and restarts are a bit delayed as well. not sure if that's due to to that issue though, just have to pump the gas a few times and BLOOOOOOM, were running, with a little ploom of smoke of course lol
 

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