Gas turned to varnish and emissions

[dochawk]

A couple of nights ago, another club member identified the smell of varnished gas (is that the right phrase) on my '72.

Most of a tank (I think) sat for a few years in the garage, and I filled the tank recently.

It's running rich enough at the moment to smell the gas, and over six times the allowed hydrocarbons out the tailpipe at idle (and double at high speed).

Will the spoiled portion affect the emission test by going out unburned?

And should I just drive off the gas, or drain it--and whiten the world do you do with drained gas?

hawk

[Bobby B]

Rich,
Hi. Unless you're looking for future issues, I would drain the tank, remove it, and flush it, along with the fuel lines. Bad gas is really not healthy for anything and is only going to clog stuff up and could possibly cause unexpected problems at any time when driving.. Two years without any additive is WAY too long. I have no idea how it would affect emissions.......
                                                                                                                     Bobby

[Jon S]

I've had gas sit in some of my cars for over 2 years and never experienced varnish. 2 weeks???

[dochawk]

 I think it was in there since 2008 or 2009.

Right now, it's probably less than half of the total feel in there, but more than a quarter.

But that is going to be 15 to 20 gallons to drain out I think â€" how do I dispose of gas I get that?

At the moment, I suspect it is clogged the filter in the new fuel pump, too. I'm waiting for my wife to come pick me up with tools…

["Cadillac Kid" Greg Surfas 15364]

Richard,
Your question "Will the spoiled portion affect the emission test by going out unburned?" Is a definite YES (and no).
What 7 or 8 years has done is two things. 1. All the MBTE or other oxygenate  originally in the mix has formed some equilibrium formula that probably is quite different than the Gasoline originally dispensed.
You have already found that it doesn't burn anywhere near well enough.
In California back in 1972 My new Eldorado would barely pass the emissions tests with ALL the emission controls correctly tuned and operable.  I am sure if you have emission testing where you are it is probably at least as California's were 44 years ago.
Running that old brew is guaranteed to have you fail an honest emissions test and will definately lead to fuel system issues in the very near future.
Greg Surfas

[dochawk]

It now seems that it may be out of gas . . .  Meaning that it's getting 4 or 5 mpg . . .

Disconnected  foul line from carb, and cranked.  Nothing.   Went home for tools, removed filter from fuel pump,  went to parts store, realized I didn't have wallet or cash, back home, to autoZone, which doesn't have it, to Napa, back to car.

Put it in, crank, still no fuel.

Remove filter and line from oil, crank, sly till no fuel.

Knock on tank . . . Sure sounds empty.

So any moment a daughter should show up with a gas can . . .

(And seems she just did)

["Cadillac Kid" Greg Surfas 15364]

no gas, no old gas, so I guess that issue is moot.
Greg Surfas

[dochawk]

no gas, no old gas, so I guess that issue is moot.

Just smaller.  I put about a gallon in, and burned most of it, I think.

But what I gathered in a glass jar from the pump was a milky yellow, not clear, so I still need to drop and dispose of some.

*sigh*

And fixing the fuel gauge just moved *way* up the priority list . . .

[The Tassie Devil(le)]

If it doesn't look right, then the only way to get it right is to remove it, and clean out the internals till it is sparkly clean.

Bruce.

[TJ Hopland]

I mentioned it in another thread recently but will mention it again here since it would apply here too.   What I do when a car is new to me or has been sitting a while is install a clear inline fuel filter between the hard line off the frame and the fuel pump.   That is usually hose anyway so you just get a long piece and route it so its out of harms way and won't kink.    That will give you an indication of what may be in your tank.   If it stays clean tank is probably clean.  If it gets dirty you know you have at least a slight problem. 

Tapping on the tank can be hard to tell whats in it.   When I have had that question what I have done is blown air down the fuel line.  You hear bubbles that means the pickup is below the fuel level and you should be able to suck fuel.    I have had several cars where the gauge float seemed to stick at the level that it sat at for a long time.   One of them this just about killed be and a buddy that thought we could push a 78 CDV a few blocks.   Dang that was a heavy car to push.    I just got used to 1/4 meaning maybe empty but then one day it started working normally so it must have finally worn through what ever crap was sticking it.

Other place there could be issues is there is short pieces of hoses between the sending unit on the top of the tank and the hard lines that run along the frame.   Usually these are located above the rear axle.   Hardly anyone ever replaces them so they could be cracked and intermittently leaking but due to their height and location you usually don't actually get a fuel leak, usually they leak air into the system and let the fuel drain back to the tank. 

[Glen]

But what I gathered in a glass jar from the pump was a milky yellow, not clear, so I still need to drop and dispose of some.

Milky fuel indicates water mixed in.  You can sometimes get a slug of water with gas.  Especially if the fuel truck is filling the station tanks at the time you are filling up.       

[Jon S]

Milky fuel indicates water mixed in.  You can sometimes get a slug of water with gas.  Especially if the fuel truck is filling the station tanks at the time you are filling up.     

Milky oil is indicative of water; I've never seen milky gasoline.  One of the biggest mistakes anyone can make is not keeping their gas tanks between 3/4 and full at all times to minimize water contamination.  I would NEVER let a tank run to empty!

[dochawk]

I've dropped the tank.  The hardest part was actually the rubber hoses, which I simply cut.  They're brittle, and need replacement.


Also, I found it dangling by a second grounding wire that the shop manual didn't mention.   There is one that clips on to the tank, and another that screws to the float mechanism.

There wasn't all that much to drain, and it was quite yellow.

I brought it to the bathtub, front-end down, and managed to fill it most of the way with hot water, then drained most of it, balanced, and sloshed hot water around.  it's now sitting on my front porch (it's 9:30 P.M., It's 101.3F and 11% on my porch); I assume that it will be bone dry in the morning . . .  (the desert has it's advantages . . .)

(uhm, does having a fuel tank on my front porch make me a redneck???)

How should I test the fuel gauge mechanism while it's out?  I read that until the 50s, it was a 30 ohm range, but what should it be for a 73?  And I'll check to make sure the float floats . . .

should I replace the gasket on top of the tank?  It's still nicely flexible.  can I even get a new one?

[Glen]

Milky oil is indicative of water; I've never seen milky gasoline.  One of the biggest mistakes anyone can make is not keeping their gas tanks between 3/4 and full at all times to minimize water contamination.  I would NEVER let a tank run to empty!

The ethanol absorbs the water and allows it to mix with the gas.  Small amounts of water are burned with the gas, but a lot of water makes the gas nonflammable.  We had it happen with a man-lift that had a leak in the top of the tank that allowed rain water in.   The gas was milky. 

[m-mman]

If your tank is out then you must use a flashlight to look in the sending unit hole and see what the metal looks like INSIDE the tank.

The conditions inside a fuel tank are some of the worst anywhere on a car. Harsh solvent like chemicals that don't mix with water thereby concentrating it against the metal surface. It is only the original galvanized surface that provides any protection against corrosion. ANY rust, crud, varnish (chemicals that have fallen out of solution) WILL end up in your fuel pump, filter and carb.

My 71 ambulance it looked clean inside but it could plug a filter (with small rusty sand like particles) in just 20-30 minutes of running(!)

Washing the tank with hot water is OK, I guess, but if it isnt 'shinny' clean then have it boiled out at a radiator shop. Maybe even opened up for sandblasting and resealing. . . . . ?

To really see inside you might consider going to Home Depot or Lowes and buying a fiber optic camera. They cost $50 $100(?) and allow you to thread a bright light and lens into the tank as see things you otherwise could not. Even if you dont view things on the camera screen itself the bright light on the goose neck arm makes an excellent flashlight. One of my better tool purchases - very handy.

[gary griffin]

When I purchased my 1957-60-S It had been driven annually a couple of miles. Big trucks can not get down my driveway so I met the transporter a couple of miles from home and drove it home without problem, but the gauge said full and not trusting it I filled the tank, and it took 2 or 3 gallons. Since it had sat for about 7 years and only driven annually I thought possibly I could drive it to the shop for brakes and upholstery repair. Every time I accelerated up a hill it stalled so I had it transported to the shop and we will be pulling the tank and inspecting it and flushing it along with the fuel lines. Surprises annoy me and so does sitting alongside the road.

[dochawk]

The shop manual says to use hot water to flush it.  (it doesn't say to take you wife's new shower curtains off the tub before bringing the tank inside . . . note to the wise)

How dry does it need to be before putting it back in and letting it have gas again?  I'm surprised to hear a tiny amount still sloshing around; it's hot and dry (and I poured out maybe a pint this morning, much to my surprise, given the way I jiggled it yesterday)

Do i need it bone dray, or are a couple of ounces OK?

[m-mman]

There exists a problem when relying solely on a shop manual that was written back when the car was new. The problem is that the car was "new"(!)

It had no dirt in the systems, no rust on the exhaust pipes and none of the plastic parts had deteriorated in the sun. . . . Shop Manuals are great and everyone should have one for their car and consult it liberally but normal aging is not something that is covered.

Hot water WILL melt out old petroleum gum and varnish. (think steam cleaning your engine) but it does nothing for the rust that developed from loss of the in tank protective coating.

Last year I worked on a 59 convertible that sat in a So California garage for about 15 years with about 7-8 gallons in the tank. It smelled horrible. I drained the 'fuel' (and now use it as a solvent for greasy parts) and saw the inside of the tank covered with yuck. Powering up my hot high pressure blaster I sprayed around inside the tank, draining and repeating several times.

Eventually I looked inside and when all the gum & varnish was gone the inside was shiny. (via camera inspection) I reinstalled the tank and the car is running fine. (Ok I had to replace the fuel pump too)

As for cleaning water left in the tank? Water and gas dont mix. Water will not burn in your engine. You want the tank to be as water free and dry as you possibly can . . . A "little bit" of water MIGHT be OK, but what is a little bit to one person is a lot to another. 

[TJ Hopland]

I too think as dry as possible.   

The non exploding trick to drying out a gas tank I always heard is to take something like a shop vac hose and loosely attach it to the tailpipe of a running car and the other end to either the filler or open sending unit hole of the tank that needs dry.   You get hot air flow without chance of boom from something like a hair dryer.

Other tricks I have heard for cleaning a tank as long as it does not have any baffles in it is to throw in a handful of sharp rocks like class5 and shake it around. 

[dochawk]

This 113 degree day has indeed taken care of the rest of the water in the tank . . .

I've attached pictures of the float (what I thought was gunk looks like woven; this seems to be a "fuel tank sending unit filter screen"--and I have no idea where to find such a thing; my searching is coming up empty for anything that will claim to fit) and the tank in the bathtub suckling from the shower line.

And should the scraped steel areas of the outside of the tank be painted or somehow sealed?