Pressurised Fuel Tank???

[Extra 300 Driver]

I dont know what but I took the cap off the fuel tank this afternoon, was cleaning the car. Fuel started to gush all over the place, loads of it, and it was under pressure.

The tank was 1/2 full and the car drove fine.

Any ideas? I am sure TVR had a problem with the T350 doeing this.

[NJW 77]

No idea Nick, but Austec did tell me (not that I listened) to release the petrol cap half a turn when you get down to half a tank or so, to release the pressure.

[Extra 300 Driver]

NJW 77 said:

No idea Nick, but Austec did tell me (not that I listened) to release the petrol cap half a turn when you get down to half a tank or so, to release the pressure.

I can see why you would do that, due to the negative pressure, but this was positive pressure and it threw fuel out at me!

[NJW 77]

Ahh, no idea then. You havent upset your car recently?

[Extra 300 Driver]

No! Thats what my girlfriend said!

I have just treated the Cerb to new bloody carpets as well.

[GreenV8S]

If the carbon cannister or vent pipes to/from it were blocked then the tank would build up vapour pressure, but unless the tank was absolutely brimming or parked on a steep slope I'd expect to get vapour rather than petrol out. Was it really just half full and on level ground?

[Extra 300 Driver]

GreenV8S said:

If the carbon cannister or vent pipes to/from it were blocked then the tank would build up vapour pressure, but unless the tank was absolutely brimming or parked on a steep slope I'd expect to get vapour rather than petrol out. Was it really just half full and on level ground?

Maybe 3/4 but on level ground. Once I had let all the fuel out, that wanted to come out, the tak made a thud.

Really got me scratching my head.

[GreenV8S]

Extra 300 Driver said:

Really got me scratching my head.

Me too. I can see how the tank could get pressurised, but not how the filler neck would be full of fuel if the tank was only 3/4 full on level ground.