[cturboaddict]

So, I'm a bit uncertain of how long my 66 car sat before I obtained it. But I know for sure it was atleast 3 years. How many times it was ran, I'm not sure.
Anyhow, after a small carb mishap (some of you may have seen my other thread), I noticed when I tore the carb down there was a significant amount of green algae type contaminents in the carb.
Fuel had a varnish type smell to it, so I'm going to assume that there was some bad gas in there. It had eaten through the diaphram of the accelerator pump.

Can I just add fresh fuel to compensate with a sea foam cleaner additive, and maybe some stabil?
Drain the tank and refill? Is there a drain plug in the stock tank?
Or replace the whole dang thing?

Tank looks to be in good condition as far as I know.

Thanks for all the help VMF!

 

[Turnall]

I would not add fresh fuel to what you have.
You could try to drain it (by taking the sending unit out). It there is not too much in it, it may be easier to just remove the whole tank from the car. I don't think there is a plug on the stock tank.
Replacing it would certainly remedy your situation but may not be necessary.

If you remove the old fuel, I would blow out the line as well and replace the filter then start with fresh fuel. It will take it a bit to get to the fuel pump and then to carburetor.

Allen

 

[cheapbastard]

Some of the stock tanks have a drain but good luck getting it out if it is 50 years old! Easiest solution might be to get one of those cheapy fuel transfer pumps from harbor freight and get as much old fuel out of it as possible then add fresh. You might have to pour fresh gas directly into the carb to get it to start. If you really want to get every last bit of old gas out of it you could take the sending unit out or remove the whole tank and pour it out of the top. If it's original you would also probably get a collection of rust and other assorted garbage. The best present I ever gave my Holley carburetor was a NEW gas tank.

 

[cturboaddict]

Some of the stock tanks have a drain but good luck getting it out if it is 50 years old! Easiest solution might be to get one of those cheapy fuel transfer pumps from harbor freight and get as much old fuel out of it as possible then add fresh. You might have to pour fresh gas directly into the carb to get it to start. If you really want to get every last bit of old gas out of it you could take the sending unit out or remove the whole tank and pour it out of the top. If it's original you would also probably get a collection of rust and other assorted garbage. The best present I ever gave my Holley carburetor was a NEW gas tank.

CJPony Parts has em for $119. I'm starting to think it's the cheapest insurance at this juncture.

 

[Israel]

I would not add fresh fuel to what you have.
You could try to drain it (by taking the sending unit out). It there is not too much in it, it may be easier to just remove the whole tank from the car. I don't think there is a plug on the stock tank.
Replacing it would certainly remedy your situation but may not be necessary.

If you remove the old fuel, I would blow out the line as well and replace the filter then start with fresh fuel. It will take it a bit to get to the fuel pump and then to carburetor.

Allen

The above approach will be a pain in the butt, but this is certainly the way to go.

 

[QuietChris]

Their used to be a place here in Austin where we would take metal gas tanks (diesel) that had algae growing in them. They had a nasty chemical concoction they soaked the tank in to kill everything before re coating and resealing it. They moved or went out of business and I don't remember the cost, but it wasn't much. You might find a place like it near you.

Thinking about it they patched radiators too, so maybe a place in that business

 

[Rufus68]

While you are working on the fuel system, it would be a good time to replace all the rubber lines because the old rubber is not tolerant to E10 fuel. This fuel line is not expensive and is approved for even E85. https://www.amazon.com/gp/product/B0013FZS62/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[2nd 66]

my car/tank sat for years and when the time came the plug cam right out . I had to keep track of fuel filters for a while but ...

 

[cturboaddict]

my car/tank sat for years and when the time came the plug cam right out . I had to keep track of fuel filters for a while but ...

So yours had a plug? I'll have to check.

 

[2nd 66]

So yours had a plug? I'll have to check.

yes. passenger side front of tank. As shown in this video ,however I would suggest using a socket vs a crescent wrench as shown

 

[DaleB]

I will second the opinion to NOT just try to dilute the bad gas with good. Nothing good can come of that. Drain the old crap out of there, clean the tank if you can. I'd flush the fuel line as well, as long as you've got the tank either opened up, or out. Just start under the hood and run some clean gasoline through the line, and drain it out from the tank end.

Your local small general aviation airport will probably be happy to sell you a gallon or five of 100LL avgas, if you tell them it's not for road use. It's wonderful stuff. Doesn't stink like pump gas, evaporates cleanly other than a little blue dye. Lots of lead, so don't shower in it. And, it doesn't go bad for a long, long time compared to car gasoline.

 

[Magnus]

If you take out the filler neck and the big rubber hose in the trunk you can get a good look into the tank and see what you're working with.

Even better if you pick up a cheap USB bore cam you can stick in there. But even without it you can see pretty well with just a flashlight.

 

[cturboaddict]

I've got the filler neck off in the paint booth right now, so I should be able to see in there just fine.
Still, I feel like the general consesus is to just replace the tank vs cleaning it out. (If there's any contaminants in there)
If it's just bad gas, then I can flush it out and move on.

 

[subpar63]

My .02 - replace the tank and upgrade to a 22 gallon tank.

John

 

[vegasloki]

 

[cturboaddict]

HAHAHA

 

[tom991]

Listen to this about bad gas.

 

[Lightning]

For as cheap as a new tank is, the best option is to siphon as much as you can out of it and replace the tank.

 

[cturboaddict]

For as cheap as a new tank is, the best option is to siphon as much as you can out of it and replace the tank.

Yeah, I'm feeling that way.

 

[66coupe289]

I went through the same thing. My car sat for a few years. I fought bad fuel. I ended up rebuilding the carb, twice, replacing the fuel pump, twice thinking it was bad, replaced all the lines back to the tank. I finally replaced the tank. Best $100 spent. There is no telling how much crap/rust is in the tank after 50+ years.

If you can salvage your sending unit, do that. The new ones suck. My tank now reads 1/4 full when it is really over half full.

The plug in my tank came out just fine. Be sure to jack the car up in the back to force all gas to front of the tank when draining.