Fuel Tank Conversion

How do I plumb a return line? Might as well do it while the body is off.

 

Jeep uses a fuel filter with a return line. Send the extra nipple back to your fuel tank.

https://www.rockauto.com/en/moreinfo.php?pk=359882&cc=1309508&pt=6200&jsn=444

There is an orifice in the filter that sends part of the fuel to the carburetor, and part to the return line.

The V6 has its own method IIRC, with an extra fitting on the fuel pump? Never existed for the F134, so it's up to you to create something.

With EFI,the throttle body has a return line. Different from carburetion.

 

You can either source a fuel pump with a return fitting, or get a 3 port fuel filter and put it inline between the pump and the carb.
the 3rd port on the fuel filter returns unnecessary fuel to the tank.

 

I'ld use the v6 fuel filter but a T in the line before a ny regulator with a small orifice (smallest drill you have to start) will do the same. It allows the fuel to vent pressure that builds after shutdown and allows some hot fuel to flow back to the tank and be replaced by cooler fuel.

A sketch would be good if someone can do that to the 4cyl fuel diagram.

 

Yes, a sketch would help. F134 engine.

 

Oh WOW! The light bulb went off with that photo!! I always wondered why some filters had two ports on one side. I learned something! Thank you!

 

What is an ny regulator?

 

Should have read "before any regulator" I guess it would work after a regulator. Pros and cons can be debated but after the pump and before the carburetor. Probably as close to the carburetor as possible would be a good start. The orifice can be anywhere in the return line but the closer to the T the better the three tube pump has one inside it or three tube filter has one inside

 

However did all those vehicles without return lines ever survive..........................

 

I think a lot has changed between fuel, trail conditions, quality replacement parts, oversights in tune or maintenance and next thing you know your temp guage has gone round. Before my TBI swap my motor would get pretty toasty. I wouldn't think of the Rubicon or Colorado as mine was before.

Thankfully the tbi will up idle when it starts getting hot.

Anyway it won't hurt anything and now is the time to add it. (I have a feeling this rig will get Hamilton fuel injection in the future)

 

By frequently installing new pumps-------- The majority of the older Jeeps were scrapped well before they accumulated half the mileage of modern vehicles.

 

Yes, with gas poured down the carbs, hoods opened to cool engines off, even starting fluid was utilized at one point. Not to mention they wasted fuel and had to be winched out of precarious spots because the fuel systems were misbehaving.
None of these old systems seal anymore, underseat tanks are the worst when it comes to sealing. Rear tanks come with vents…
The majority of issues stem from heat and altitude.

 

LOL
Don't confuse carburetor issues with fuel system venting issues.

 

The LOL is the part of this discussion where you somehow think that these old Jeep fuel systems aren’t venting .
Literally every Jeep is spilling fuel out the drivers side filler neck when they lean over. Every one of them has the same paint damage to match.

 

Reason #379 why you need a fuel return line.
It's kinda funny that he is working on a fuel system with a cigarette in his hand.

 

And that, ladies and gentlemen, is why I'm not painting it. Wipe it off with a rag and forget about it is something I'd never do with my nice Dakota, but the Jeep's bad paint offers me that freedom.

 

I’m not sure I understand the orifice thing. The video mentions it and JW60 does too. Which filter should I buy? Anybody have a part number? What if I don’t have a smaller “orifice” on that recirculating line?

 

I am running the same fuel filter I ran in my 1988 YJ with a 258 carburetor I6. It has a built in bypass in it and I have zero fuel pressure/flow issues. Pay attention to the orientation. I think the bypass line has to be above the line running to the carb. I think there is an arrow on it.

 

The filter and pump will have an orifice within the extra hose barb. The orifice is a fixed bleed just like a carburetor but it is bleeding a little fuel out, not too much to where the pump has to work a lot but enough so that pressure or vapors do not build in the line keeping the pump from moving fuel.
The 3 fitting filter must be used after the fuel pump for it to not pull air in.

The T and restriction in the return line would be for if you wanted the return to start right up at the carburetor. Probably unnecessary.

I would run the stock lines but use a filter with return right at the pump outlet or somewhere close so the return line can parallel the fresh fuel path.

 

No, the LOL is your failure to read the post........................