Pressurized fuel tank?

[stradlater]

I noticed after driving the celica for only about 2x20 minutes, that there was fuel spurting itself back up my fuel filler neck.

Seemingly because it's the weakest point, the fuel leaked out between the rubber connecting hose, and the metal part of the filler neck.

I then pulled the filler cap off, and noticed that it had fuel all the way up there too, not that the fuel was pooling there, just that it was clearly splashed all over everything in that area.

What on earth would cause this?

I wasn't doing excessive cornering or anything, so it wasn't like it was slushing around.

I just got the impression that it was either too hot, or pressurized in some way.

Thoughts and/or solutions?

[oldcorollas]

where does the fuel return pipe go? to a tube that runs to bottom of tank? or dropping and splashing from the top?

tank feel warm?

[roadsailing]

My sprinter used to do this, but fuel never actually got out, just goes "PSSHHRRRRRR" when i take the lid off my corona does it too, but it never leaks either, probably because i dont usually fill cars up unless im going on a long trip. NFI what does it but i dont think its a gunked charcoal can, as i uhooked the fume line from the tank and nothing happened.

[stradlater]

I actually didnt' get to check the tank temperature.

The return pipe from the engine goes to the highest side entry on the surge tank, and the overflow out the TOP of the surge tank goes back into the top of the fuel tank. I think I might ahve used one of the returns into the tank that is a pipe about half the way down, but I also may not have.

So it'd be safe to say that it could be dropping and splashing from the top of the tank.

What do you think that woudl cause? heat type symptoms? Or just a lot of turbulence/motion hence the overflow?

[oldcorollas]

if the fuel is splashing back down and aerating, it can vapourise more easily and increase the petrol vapour pressure, but i don't know how much.
have you actually noticed any pressur etho?

how high is the filler above the tank level.. thinking what G cornering force would be needed to force fuel all the way up there.. if tank is full.. maybe not that much? (ie 1G = 45deg angle)

[pandaah]

checked that the pipes going to the fuel vapour seperator isnt blocked ?

[stradlater]

problem is it was bubbling up and out when I was stationary, so the cornering thing is out I think.


Fuel Vapour seperator?? What/where is that pandaah?

[thechuckster]

line to charcoal cannister may also be bloked - that will help equalise tank pressure when motor is running (assuming that it's still present)?

[oldcorollas]

err... the retunr pipe from the surge tank is not the one that goes up near the fuel filler.. to allow air to get out of tank while filling up?
i dunno what your tank is like, but might be a possibility?

[rodi]

is this a turbo car???

[pandaah]

if you run the car with the cap off does the tank still overflow?...

maybe your engine just creates fuel and fills your tank for free... best car ever

[shelldrake]

if you run the car with the cap off does the tank still overflow?...

maybe your engine just creates fuel and fills your tank for free... best car ever

Lol! Vote 2 for the Charcoal cannister line. My tank was pressurising due to this line.

Unplug at both ends and blow out with compressed air. Leave disconnected at the cannister end, then try again. Not sure about legalities, but my line is disconnected and vents to atmo way back near the tank now...

[rodi]

if its turbo the vacc line to canister if plumbed incorrectly can pressurise the tank

[stradlater]

I don't have any charcoal canister?

I just have my surge tank setup, and one big line going to the engine, and another line returning - back to the surge tank.

Have I missed something? I didn't think it needed anything else for an EFI car?

[Cuts]

so this has only started happening after you installed a surge tank and efi into the car?