# Fuel filters clog up fast on '67 2bbl. Possible tank sock issue?



## redgoat67 (Sep 23, 2011)

My '67 GTO with a 2bbl carb has been hard to start lately--actually took a notion not to start at all. It's done this before months ago and I replaced the small fuel filter at the carb inlet. Problem cured. Last year I added an in-line see-thru filter at the exit of fuel tank for belt and suspenders protection. Today, I examined the add-on filter and it was black. Probably had 200 miles on it. I replaced the add-on filter with a new one and I then tried to start car but to no avail. I then replaced the small filter at the carb and it started right up. It seems that BOTH filters must have been clogged. My gas tank is 48 years old. I regularly use StaBil since the car is not driven much in the winter. . . but is started regularly. Is there a sock filter in the gas tank that could be causing my problems with external filters? How hard is it to replace it?


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## pjw1967 (Mar 10, 2014)

When I bought my '67 in 1994, the gas tank had been out of the car for a while during the restoration. I made the mistake of filing the tank with gas shortly after receiving the car in New Orleans. As best I can tell, the underside of the top of the tank was all rusty, which was washed off into the fuel when the gas hit it. Had to get a rebuilt carb it was so bad. Took the tank out and brought it to a local shop for cleaning and sealing. Last year I got a stainless steel tank as I was tired of the slight leak at the sending unit. So maybe it's time for you to do the same. See photos here http://s1355.photobucket.com/user/pjw1967/library/GTO tank


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## mytmouz (Mar 20, 2015)

Yes it has a 'sock' in the tank...


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## redgoat67 (Sep 23, 2011)

Could the "sock" be clogging or disintegrating. If so, how do I get to it to replace it?


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## geeteeohguy (Feb 2, 2008)

The sock is nylon mesh, light gray in color. I removed mine in 1988 and never put another on. It got sucked in like one of those party favors you blow on and didn't allow for any fuel. My tank is original as well, but rust free due to the car never being out of service. Sounds like you need to address a rusty fuel tank, or install another big fuel filter in line between the tank and pump. You want to change the filter in your carb never or almost never.....those inlet threads have a shelf life. Much better off using downstream filters, and changing/checking regularly.


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## mytmouz (Mar 20, 2015)

I have had good luck with having a radiator shop cleaning out and relining the inside of tanks in the past. A new sock was pretty cheap on the GTO I am working on now. I replaced it. In my opinion you can never have too many filters...


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## ALKYGTO (Mar 29, 2010)

Yes but the sock is a restriction and it would be better to be able to inspect and clean the filter if need be. Also the stock sintered bronze filter is a restriction and I would remove that also and never need to take that fitting off the Qjet again as GeeTee said. I would recommend two filters, one between the tank and fuel pump and one between the pump and the carb. 

Also try to minimize the amount of rubber fuel line in your fuel system as the rubber deteriorates from the inside out (alcohol in the fuel accelerates this process) and the rubber will cause problems in your carb and is a hazard if it leaks fuel, check rubber fuel lines often.


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## Goat Roper (Oct 28, 2014)

Old nasty almost 50 year old dented tank in my '67 and for 250 bucks it wasn't worth screwing with.
I bought a repop, new sending unit and replaced the lines.
You will spend more time and money screwing with the old one IMO and I don't like on the road repairs because of clogged filters.


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## pjw1967 (Mar 10, 2014)

I failed to directly answer your question the first time around. As stated above, yes there is a sock. How to get to it. Here are 2 photos, sort of before and after. The before photo shows the old tank and sending unit in place. Because the sending unit had been removed and replaced a number of times without the proper tool, the seat for the "O" ring was beat up. So I used gas tank patch to keep gas from drooling out. As you can see, there might be enough room to try to get it out without removing the tank. Since the tank is only held in with 2 big bolts, it's no big deal to take it out. You should consider identifying what the problem is before replacing the sock, as it could clog up again if your tank has some sort of debris in it.
The second photo is the new sending unit installed. 2 places are circled. The larger circle shows the leading edge of the sending unit lockdown ring (3). The smaller circle shows the trailing edge where the tine hits the stop. There is a tool for installing the unit but I have never seen one. My brother and I spend about 1/2 hour pushing and prodding to get the leading edges under the outer ring without damaging the seat, etc. We finally succeeded. BTW, the "O" ring under the sending unit of your tank is likely 48years old. When you remove the sending unit, don't be surprised if you can't reuse it. Suggest you buy one along with the sock. The degree of difficulty for reinstalling the sending unit is another reason to consider removing the tank. Good luck.


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## redgoat67 (Sep 23, 2011)

With all the responses it is definitely clear that my problem was fuel related. I've got spark, air, but not always fuel. I have replaced both fuel filters now and my car seems to start and run normally. I also replaced all rubber fuel lines and fuel pump last year. I suspected my "no start" problem was fuel related and that it could have been a combination of stale ethanol fuel in a 3/4th empty tank, perhaps moisture in tank over the winter, maybe some rust?, and most likely 2 clogged fuel filters. Before I replace the fuel tank with a new one, I think I will closely monitor my see-thru fuel filter located near the gas tank. If it becomes dirty again I will not only know the filter is doing its job but also I need to seriously consider replacing my fuel tank. Being the original owner of this classic, I know the complete history of all maintenance done to it. Like the original gas tank has never been removed from the car nor has it ever been damaged. My gas gauge still works just fine. The car was "undercoated" when I bought it 48 years ago so chassis rust is minimal. BTW, I use Premium gas and add a lead substitute as well as StarTron enzyme fuel treatment additive to lessen the potential harmful effects of ethanol. 
Thanks to all responders for the plethora of information and suggestions.


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## pjw1967 (Mar 10, 2014)

Thanks for the feedback. BTW congrats for hanging onto the 2 bbl. Stats say there were about 3,000 equipped that way. I once heard a guy say that my post coupe must have been a clone since there were no Goats made as post cars. Anyone ever accuse you of having a clone because of the 2 bbl?


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## chuckha62 (Apr 5, 2010)

My '67 post coupe was originally a 2bbl car, as well. It was changed to a Quadrajet before I got it so the original manifold and carb are long gone. I was fortunate enough to find a date code correct Quadrajet and manifold a couple of years back, but never even thought to try to find the two barrel parts.


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## redgoat67 (Sep 23, 2011)

I looked again at my sending unit's exterior because I did not remember having two hoses connecting to it. Several responders mentioned a "return" hose. My tank only has one fuel outlet that has a short hose that connects to a steel fuel line that ends at the fuel pump. The other 2 wires are for the fuel gauge and the other wire is a ground wire. Do you suppose that because my GTO is a factory 2bbl rather than a quadrajet that there is no return hose? What is the purpose of a return hose anyway? Also you can see in the photos where I spliced in my add-on see-thru fuel filter.


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## pjw1967 (Mar 10, 2014)

Another heehaw moment for me. I should have mentioned this at the beginning. The second, smaller line is a vapor return line, specifically for cars with A/C. The idea was to prevent vapor lock, a condition that having factory A/C can cause due to the add'l heat that A/C puts into the engine room. The '67 service manual makes no distinction between 2bbl and 4bbl models, only that the vapor return line is found on V8's with A/C. So my guess is that your car does not have A/C.


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## mytmouz (Mar 20, 2015)

The 1966 post car I am working on is a non AC/stick car and it has the return line...


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