TheSilverBuick's 1967 Thunderbird

[STINEY]

AAaaghh!!! That stinks! Is this the brass fitting in the pickup assembly return, like on DIYautotune?

You just reminded me that welding in a good sized return fitting elsewhere on the Cadistang tank needs to be done..... think I'll just weld a 1/2" bung in somewhere out of the way. Might weld another 1/2'" nut in on the bottom for a drain while I'm at it.

[BBR]

My first question would be: Is the tank vented properly/not clogged.

[STINEY]

Good pointer BBR......for some reason around here the Mud Daubers love to pack the vent tubes on older (non charcoal canister) cars with mud. The Bird would certainly qualify for having a vent they prefer, easy enough to check.

[stage1scott]

FORDS SUCK! so there I was, shining up the Sublime Fairlane for its maidnen debut tomorrow morning at wilwood for the anti-tour kick off-lots and lots of details to be finished, including a trip to the chassis shop next week about the rear suspensions-but hell, I can make a 20 mile round tirp, right? HELL NO-#6 rockr arm adjuster broke off at the pushrod contact area, on the last test drive before putting it away for the night.... oh well at least it didnt happen half way there. Randalls T Bird and my fairlane side lined......

[Scott Liggett]

FORDS SUCK! so there I was, shining up the Sublime Fairlane for its maidnen debut tomorrow morning at wilwood for the anti-tour kick off-lots and lots of details to be finished, including a trip to the chassis shop next week about the rear suspensions-but hell, I can make a 20 mile round tirp, right? HELL NO-#6 rockr arm adjuster broke off at the pushrod contact area, on the last test drive before putting it away for the night.... oh well at least it didnt happen half way there. Randalls T Bird and my fairlane side lined......

Bring it anyways. Ford are designed to run on seven cylinders.

[TheSilverBuick]

AAaaghh!!! That stinks! Is this the brass fitting in the pickup assembly return, like on DIYautotune?

You just reminded me that welding in a good sized return fitting elsewhere on the Cadistang tank needs to be done..... think I'll just weld a 1/2" bung in somewhere out of the way. Might weld another 1/2'" nut in on the bottom for a drain while I'm at it.

No, I didn't use that method on this car, though I am considering it. I mounted the return line in the filler tube, which is a bear to seal being round. The other issue is the seal for the filler tube to the gas tank. The new gas tank didn't come with one and I did not find a source for one when I replaced the gas tank, so it's a nice 1967 vintage seal. Both those are in the same area, so I'll have to check out which it is, or could be both.

It's definitely not a venting problem, it started leaking as I was filling up the tank.

[STINEY]

If it is similar in design to this http://www.latemodelrestoration.com/...r-Neck-Grommet

Then maybe LateModelRestoration can help? They have more than one listed, hope that helps.

[TheSilverBuick]

If it is similar in design to this http://www.latemodelrestoration.com/...r-Neck-Grommet

Then maybe LateModelRestoration can help? They have more than one listed, hope that helps.

I don't see anything that looks like it'll work. This thing is pretty large.

[TheSilverBuick]

You know that work you did years ago, that when you re-visit it you wonder what in the world were you thinking? This is one of those cases.

This was my first EFI install four years ago and first time I had to run a return line. I didn't really know where to run the return line, but at the time it seemed like the filler neck was a prime candidate to install the return line. I had read a few places where people had installed the return lines in the filler neck. So my fabricating skills suck, and they sucked a lot more a short four years ago!

So this is what I started with. I had already disconnected the fuel line from the filler neck. It was leaking at the connection with the filler neck, the sealant I had used failed. The big problem is the tube is round and tightening the fitting didn't work to well. I had hammered it a bit to try and flatten the surface for the fitting to seal to, but it wasn't done very well. The RTV sealant I used was a hardening sealant and I think that was the main reason it failed. I had the same issues with the filler neck to the gas tank, but switched to a non-hardening RTV (both types were fuel resistant) and worked great.



So I'm going to weld a fitting to the filler neck that a rubber hose can be clamped on to. Just a simple 5/16th tube and a flat washer.


Should fill this hole nicely.


In the mean time, since I plan on welding on it I have the filler neck sitting in dawn soap and water for the gasoline. The hole in the gas tank is currently ducktaped over.

[TheSilverBuick]

Here is my fix. This is try number three. First try I eventually blew through the small pipe, so I made another one and forgetting that lower gauge numbers mean more heat on the welder I promptly blew through number 2. Once I had that figured out this one went smoothly. The welds actually looked pretty decent when I was done, but I wanted to grind them down to make sure it was sealed all the way around. I couldn't make it stick out any further because then it wouldn't fit through the hole in the body.

[CDMBill]

On my first return style setup I did the same thing except I welded on an AN male to the pipe. Only thing was it was too small and I saw post regulator pressure on the return side so out it cam and in went the #10 directly back to the tank. I modified the original fuel barb, gas gauge float assembly for the #10 coupler with an extension on the inside to get the returning fuel to the top of the tank. I was then told to return the fuel into the fuel mass so I bent down the in tank tube. I'm still not sure about this theory.

Your welding/grinding job looks good. Mine not so much. I removed it when modified the gas tank location slightly for the trailer hitch.



I sealed up the gauge flange with JB weld which worked for four years.

[milner351]

nice work Randal.

[TheSilverBuick]

Only thing was it was too small and I saw post regulator pressure on the return side

In another "learning experience" since this was my first go at it, is the return line going back to the gas tank is only a dinky 1/4"! I have no idea if I'm seeing return line pressure or not. It has a 3/8th's feed from a stock mechanical fuel pump going into the surge tank and unrestricted 1/4" back to the gas tank. Kinda sketchy even by my standards. I used a 5/16th fitting on the gas tank and will use a 1/4" fitting to 5/16" hose fitting adapter on the end of the return line, but I see a possible upgrade to 5/16th or 3/8th line in the future if I go MPI. The Skylark has 3/8th feed and 5/16th return, but I could quickly swap out to the vapor canister 3/8th line (retrospect!) back to the gas tank if I think it becomes a problem. The restriction in the vapor return line should be at the sending unit, not in the lines. Plus the Skylark's electric fuel pump is 5/16th, LOL.

Thanks John

[TheSilverBuick]

Finished up the job. Should be good to go now. I'm letting the RTV on the seal cure overnight before testing it.

This was what was limiting how tall I could leave the fitting. Got it perfect


Fitted and finished.

[milner351]

Nice work! Do you recall what the return line size was on the donor car you got the throttle body from? Matching the OEM size would be safe... right? Have you had any symptoms (running rich?) that could be a sign of restriction/high pressure?