Fuel Tank Issues. DANGER!

[Lord Umoja]

I have noticed recently that my fuel tank is "venting" when I open the gas cap to fill up. By venting I mean a noticable "pssshhht" like opening a new soda sound. Today I filled up my tank and drove about 10 miles with a full tank (Fuel light came on, filled up till the pump shut off, just over 13 gals) then parked at work in the sun. Now there is a puddle of gas under the car, and it seems to be running down the side of the tank, forming a pool at the bottom and dripping to the ground.

Does anyone have any idea what would be causing this? I really don't feel all too safe driving the car unil this issue is fixed. ANY help would be greatly apprciated. You can see my car in my build thred here:

new-to-nico-resurrecting-a-93-vert-mega ... 55579.html

Sorry if I come off as a noob on this, fuel injection systems are not really my forte'.

[h2v7]

could be that o-ring thing on the top of the tank

or a line or who knows start loooking

[Lord Umoja]

In case it helps with diagnosis, the car also likes to nearly stall at stop lightws if I hit the brakes hard with the air on high but no AC....

I checked the evap canister and it looks to be all connected, but I'm going to replace it with a spare this weekend.

[Razi]

The "pssst" is normal.
As for the leaking, check all the fuel lines.

[Lord Umoja]

The "pssst" is normal.
As for the leaking, check all the fuel lines.

The venting from the gas cap is normal? I've never encountered a car that pressurized its tank like this car does. Just seems odd to me. The leak was high in the filler neck so I think the tank was burping fuel after pressurizing. Then again I've been wrong before. I used to think the focus was a cool car

[mechanicalmoron]

The "pssst" is normal.
As for the leaking, check all the fuel lines.

The venting from the gas cap is normal? I've never encountered a car that pressurized its tank like this car does. Just seems odd to me. The leak was high in the filler neck so I think the tank was burping fuel after pressurizing. Then again I've been wrong before. I used to think the focus was a cool car

It is normal.

I think newer cars have vaccum on the tank, or something, in such a way that there may be no pressure. But it's totally normal on this car, especially on a hot day or after driving.

There is a panel in your trunk that grants access to the top of the tank. Do NOT remove the panel below that one (the one on top of the tank itself) without cleaning or you'll have stuff fall in the tank, but if you just take out the trunk panel you may be able to see if it's the tank seal, or if it's a line. I expect that if it's really leaking gas and there's no puncture on the bottom of the tank, it's comming around a hose clamp or through a crack on the short section of hose connecting the tank to the hard fuel lines.

Did you smell the puddle, and are you sure it's gas? It could be condensate from a freshly filled tank, that was hot until you filled it with thirteen gallons of cold gas. Maybe the hiss made you overthink this, too?

There should be NO gas on the ground, but if there's water, I wouldn't be worried.

[Lord Umoja]

The "pssst" is normal.
As for the leaking, check all the fuel lines.

Did you smell the puddle, and are you sure it's gas? It could be condensate from a freshly filled tank, that was hot until you filled it with thirteen gallons of cold gas. Maybe the hiss made you overthink.

I'm positive it was actual gas. I smelled the puddle, the stench of gas carried pretty far, and it was removing the road grime from tank outside.

I'll pull the panel this weekend. It stopped leaking after I drove the car a bit.

[mechanicalmoron]

I'm positive it was actual gas. I smelled the puddle, the stench of gas carried pretty far, and it was removing the road grime from tank outside.

I'll pull the panel this weekend. It stopped leaking after I drove the car a bit.

If you'd just filled up, if you splashed a little gas around the hole I think that pinhole drains into the fender, not the tank.... is the only other non-leaking thing I can think of.

Anyway, taking off the panel is no big deal, it's a ten minute job. If there's a strong smell of gas under it, you've probly got a leaking hose and can go from there. And if there's nothing at first, set the ignition at "on" without starting the engine, so that there's fuel pressure, and check again.

[zmannz]

I f you plan to open that, save yourself trouble later and go ahead and replace all the soft lines you can get to. Last build I threw my walbro in, got the car done, then lost fuel pressure a day after it was running because the high presure line split right through. I went ahead and dropped the tank after that and got it all fixed the right way since I had access to a lift.

[mechanicalmoron]

I f you plan to open that, save yourself trouble later and go ahead and replace all the soft lines you can get to. Last build I threw my walbro in, got the car done, then lost fuel pressure a day after it was running because the high presure line split right through. I went ahead and dropped the tank after that and got it all fixed the right way since I had access to a lift.

Since you're saying you've done it....

I'm suspicious of my soft lines, especially given my suspicions of the garage that I had do my fuel pump (I pulled the thing out in the autozone parking lot, and then the register jerk told me that he had meant it was at the hub, a day away.... I jammed it in and limped to a garage, who messed everything up), and would like to do them.

How hard is it to drop it? If it's run down to a few gallons, is there a way to do it with the car on jackstands and access to one floor jack? Maybe with two people? Heavy or no?

[Lord Umoja]

I f you plan to open that, save yourself trouble later and go ahead and replace all the soft lines you can get to. Last build I threw my walbro in, got the car done, then lost fuel pressure a day after it was running because the high presure line split right through. I went ahead and dropped the tank after that and got it all fixed the right way since I had access to a lift.

Since you're saying you've done it....

I'm suspicious of my soft lines, especially given my suspicions of the garage that I had do my fuel pump (I pulled the thing out in the autozone parking lot, and then the register jerk told me that he had meant it was at the hub, a day away.... I jammed it in and limped to a garage, who messed everything up), and would like to do them.

How hard is it to drop it? If it's run down to a few gallons, is there a way to do it with the car on jackstands and access to one floor jack? Maybe with two people? Heavy or no?

Dropping the tank isn't really hard, more just kinda awkward. It's held in with two straps under the car and a gasket around the filler neck IIRC. I dropped the tank on my coupe in preparation for a fuel cell. I did it on just jack stands and a floor jack.

[Dimitri]

The lines coming out of the fuel tank can be replaced without dropping the tank.
Once you remove the fuel pump cover hiding under the trunk carpet, you can see the two fuel hoses coming out.
If it does turn out one of them is leaking, replace both and make sure you get fuel line for high pressure
And of course don't forget to relieve the fuel pressure from the lines before you start disconnecting them

[mechanicalmoron]

The lines coming out of the fuel tank can be replaced without dropping the tank.
Once you remove the fuel pump cover hiding under the trunk carpet, you can see the two fuel hoses coming out.
If it does turn out one of them is leaking, replace both and make sure you get fuel line for high pressure
And of course don't forget to relieve the fuel pressure from the lines before you start disconnecting them

Last time I was doing this, I couldn't reach the hardline, or even see it, in the space between the tank and trunk....

[Dimitri]

On the '90 hatch the connection to the hard lines is accessible by crawling under. A lot less fuss than dropping the tank

[mechanicalmoron]

On the '90 hatch the connection to the hard lines is accessible by crawling under. A lot less fuss than dropping the tank

Ahh, I assumed that the hardlines ran up to right by the top of the tank, but that would be waaaay nicer.

I assume it didn't change for 92/dohc?

[zmannz]

I took my tank out of both my s13 and s14 at one point to do this and other things. I had my tank almost empty, on the s14 I had a lift to use so I drained it all into a couple of little gas cans(an man did some trash come out of my tank! Lots leafy type debris and random s***) but on either car all you do IIRC is get the tank straps loose, and then when you are letting down there is a part that pushes onto the filer neck and there is an oring there you may want to replace too. So, in steps:

-wait til you are on e or close
-Disconnect the fuel pump connector on top of the tank (gotta take the lid and sender out anyway)
-turn the car over and let it run a minute so the fuel pressure runs out, OR just pull the lines at the front and let it drain back, probably a good time to change the fuel filter anyway
-Disconnect the cap and sender/etc from lines and connectors, just leave the cap in it so you don't get trash in it
-jack the car up and use some jack stands (wood shims between rails and stands so you don dent them) make sure stands don't get in the way
undo the straps, I did them both from the back because the front bolt for one is obstructed by the subframe/diff housing
-pull down and jiggle til the filler neck pops out
-replace hoses, lines, clean the underside of car, look for rust anywhere
-make it all pretty and prep new lines from the body hardlines the same length as the old ones
- and finally, reassemble.


Yes, true it may not be absolutely necessary but it is great to know that your car is solid in places you can't often get to, and you can check the tank out. I am the type that just does it right when it is time to do it...