fuel tank leak?

[kned33]

I have a 91 Festiva GL. Right after I bought I smelled gasoline while driving it home. I checked all the connection through both of the access plates in back. They don't appear to be leaking. The foam padding that seals the gas connection area on top was dry but wet with gas on the bottom front. I pulled the tank. (Still had maybe a quarter tank of gas) Most of it had leaked out from an almost full tank. Problem is I could not pinpoint where the gas is leaking from. Any ideas.

thanks ahead of time
kned33

[Pu241]

Assuming the tank is still out of the car!
Put about a gallon, or less, of gas in the tank and rotate. let each side(4) and the bottom sit till you are sure its not leaking.
You know when you've found the side containing the hole.
Best to do this out sound away from lit cigs and open flames.
Also cover the access port so as not to let cra.... stuff get into the tank.

Once found the hole, you have to determine if you are going have it professionally done, DIY, or find another tank (which you hope is better than the one you have) or order a new after market tank!
Good luck, at $3 a gallon you need this thing fixed ASAP!

[kned33]

Assuming the tank is still out of the car!
Put about a gallon, or less, of gas in the tank and rotate. let each side(4) and the bottom sit till you are sure its not leaking.
You know when you've found the side containing the hole.
Best to do this out sound away from lit cigs and open flames.
Also cover the access port so as not to let cra.... stuff get into the tank.

Once found the hole, you have to determine if you are going have it professionally done, DIY, or find another tank (which you hope is better than the one you have) or order a new after market tank!
Good luck, at $3 a gallon you need this thing fixed ASAP!

The tank is still out. I did cover up all the ports so gas wouldn't evaporate and so water/junk can't get in. Is it possible that the tank might only leak under pressure? I have about two gallons of gas in tank. I have it tilted toward side I suspect leak is on. But 'm not seeing a leak. Re-checking will have to wait until morning. No garage or shop so I'm parked on my weed patch lawn and off the street. Gas here just went down to $3.31 per gal. Thanks for idea.

kned33

[Pu241]

[quote="kned33 Is it possible that the tank might only leak under pressure?[/quote]

Tank should have very little , if any pressure, if all is as it should be with the tank connections.
Just reaching now, but is it possible the "wet" area was from the return line leaking onto the tank from above it,
and that the tank itself doesn't have a hole in it? Did you notice a wet spot under the car when it isn't running?
If it leaks when it isn't running I would suspect the tank, if it only looses fuel when running
I'd suspect a fueline ( to engine, from engine, or possibly vent line).
Let us know what you find!

[FB71]

1 - 1.5 psi max is what the tank (valves) is expected to tolerate

[kned33]

Pu241

It was leaking while engine not running. The return fuel line was not leaking. The main area I found gas at was the bottom of the foam rubber sealing the connection area. My guess is that it is evaporating out of the foam before much hits the ground. I do know alot of pressure is building up. I hear a swoosh sound everytime I removed the gas tank seal. What regulates the gas tank pressure. I have bought some factory shop manuals thru ebay but they haven't arrived yet. How do I measure gas tank pressure? Cheaply?

I didn't have a chance to look at tank today. But will have some time tomorrow.

Thanks for info.

[stefan]

must be contagious

[kned33]

FB71

What is the tank valves?

[FB71]

the roll-over valve, purge control valve and atmospheric vent valve in the cap

[kned33]

the roll-over valve, purge control valve and atmospheric vent valve in the cap

Some previous owner put a none stock gas cap on. I will replace it with a Festiva capable cap. I also discovered that the leak seems to be coming from somewhere around where that long metal tubing is attach below the ports. The higher the pressure the more it leaks. The hard part is knowing where the leak is exactly is. Will let you know what I decide.

[25Horseplay]

The fill tube might be rusted out, does leak when filling up?

[kned33]

The fill tube might be rusted out, does leak when filling up?

The tank and fill tube show no rust at all. I suspect it is more of a stress fracture where the tube that is soldered on flat below the fill tube is at. ANd the leak is very, very slow. I lost about 5 gallons in a week. It seems to be a continuous leak. I'm going to check with a local tank repair place and see what they say.

[kned33]

I decided to buy a new Spectra Premium gas tank through "tanks-to-pans.com". It is only $163.45 plus $27.50 for shipping in the continental U. S. I just didn't trust my old tank even if repaired. All that excess pressure may have weakened some other area of the tank. I prefer to deal with this problem once.

[kned33]

After delay in shipping I finally got my tank last Friday. Unfortunately, it has been raining since. I had a patch of no rain today so I undercoated it. It is currently drying in the back of my 88 festiva using the cardboard box it came in to set it on. I hope I can get it running soon because the brakes just went out on my Ford Explorer. Will let you all know when I'm back on the road. :wink:

[Safety Guy]

Good luck kned!

Karl