Bad Fuel Smell after long high speed run

[tokyogtr]

Started off on the aqualine yesterday with just under half a tank of fuel. hit about 270kph max on the way back home and was keeping a steady 200kph for about 20mins, then some in town driving to get home.

when i parked up i had 1/4 of a tank left. turned the engine off and heard what sounded like a small motor running at the back of the car. went to check it out and there was a bad smell of fuel. could hear this "motor" outside the car too. turned the car back on to see if it would cancel the motor out but made no difference. hunted high and low, even in the trunk.

then i opened the fuel cap and GUSH... it started sucking in the air like you couldn't imagine, just kept sucking and sucking (please, no comments about how useful that would be on a lonely night). i went to put the fuel cap back on but it was still sucking air. don't get me wrong, all my cars have had an initial gushing noise but this went on for at least 60 secs.

after about a min i had to go so put the cap back on. the so called "motor" noise had stopped. i figure it was some sort of equalizing tube that has got jammed up with something.

looks like i'll have to take it back to the HPC. my only concern is this is a SERIOUS vacuum being created in the fuel tank. what are the potential remifications?

when i got in the car this morning there was definitely an odd smell, half fuel half glue. hope this is not some sort of design fault. also, how hard does the fuel pump have to work if sucking fuel from a tank with such an extreme vacuum?

[First]

I have constantly driven 189km/h on ends for extended periods on my R35 so far.

I do notice the exact same thing of gushing noise but I wasn't so sure if it was sucking air in. Seems to me its pushing air out? Or am I totally wrong and you definately right on the fuel smell. I can smell it too but I have not notice it inside the car though. This could be a sideeffect of splitting the fuel tanks in half and connected marginally only.

Whenever the fuel tank is hot, it does the gushing sound. If you drive the car lightly on extended periods, it does much less of the gushing sound. Thats what I notice so far so I go into a habit of opening the fuel cap for a min or 2 with the cap still on, just lightly unscrewed to let it equalised before heading in the house door.

What gives?

[tokyogtr]

Originally Posted by First

I have constantly driven 189km/h on ends for extended periods on my R35 so far.

I do notice the exact same thing of gushing noise but I wasn't so sure if it was sucking air in. Seems to me its pushing air out? Or am I totally wrong and you definately right on the fuel smell. I can smell it too but I have not notice it inside the car though. This could be a sideeffect of splitting the fuel tanks in half and connected marginally only.

Whenever the fuel tank is hot, it does the gushing sound. If you drive the car lightly on extended periods, it does much less of the gushing sound. Thats what I notice so far so I go into a habit of opening the fuel cap for a min or 2 with the cap still on, just lightly unscrewed to let it equalised before heading in the house door.

What gives?

yes, my car had been sitting in 30 degrees C all day so it was baking hot. this is the first time it's happened because it only just started getting hot here and usually i don't park it outside.

[Chamber]

sounds quite bad but does it sound dangerous? i mean it's a fuel smell; that can't be good right? i'm hoping it's not a design fault....on our car little family car (Nissan Almera ) when i drive that hard or high speed theres a little gush sometimes when we fill it up but 60 seconds..that's a lot! (i know there is a BIG BIG BIG BIG BIG BIG difference between an Almera and a GT-R )

let us know what happens, thanks

[R33_GTS-t]

I'd imagine that if you use a lot of fuel from a sealed tank a vacuum is left. The extent of the vacuum should be dependent on the amount of fuel you use. Just a theory though.

[minos]

im no skyline specialist but maybe it's becouse the ECU does not allow the PCV valve to open when going fast, to make sure your fuel air mixture isn't too lean.

There for the PCV don't get to vent the fuel tank? builng up high pressure (higher than normal becouse the exhaust heats up the tank, increasing the presure furter.

[otakki]

Originally Posted by tokyogtr

it started sucking in the air like you couldn't imagine, just kept sucking and sucking (please, no comments about how useful that would be on a lonely night). i went to put the fuel cap back on but it was still sucking air.

Gosh, it sounds like the tank might implode if you hadn't opened the cap. I thought pressure would usually build up inside the tank when there is so much heat around the tank.

Maybe the engine is just really thirsty and wants to suck in more gasoline

[R33_GTS-t]

^Didn't think about that. Whichever way the air is going. Nothing to worry about.

[Philip]

Originally Posted by otakki

Gosh, it sounds like the tank might implode if you hadn't opened the cap. I thought pressure would usually build up inside the tank when there is so much heat around the tank.

Maybe the engine is just really thirsty and wants to suck in more gasoline

Yes. Nissan clearly haven't considered that the car might be driven quickly. It's a deathtrap. Call a lawyer - IMMEDIATELY!

Phil

[tokyogtr]

Originally Posted by Philip

Yes. Nissan clearly haven't considered that the car might be driven quickly. It's a deathtrap. Call a lawyer - IMMEDIATELY!

Phil

love the sarcasm. but i still wonder how the vacuum affects the fuel pump?

[Philip]

I'm sure they thought about it.

Phil

[tokyogtr]

i guess the only thing i can do is ask the HPC. i'll report back.

[otakki]

Originally Posted by tokyogtr

love the sarcasm. but i still wonder how the vacuum affects the fuel pump?

As we all know regarding any kinds of pump, it definitely creates lots of load on the fuel pump as it tries to pump from a vacuum. Most likely unnecessary overheating to the fuel pump and premature failure unless there is a vent to allow air entry. Hmm...I wonder where did the fuel go. How did it suck in the air when there is still fuel around?! Did it just regurgitate the fuel afterward?

Yes, car makers try to think of everything...but there is only so much they can do. There are always things left to be debugged and improved on the beta version...like that recent change to stiffer engine mount. Consumers' reports and findings are a good source to find out the small bits that need to be fixed for future production. That is why software companies pays gamers to play and find bugs...and pharmaceutical companies asking health care providers to report adverse drug reactions. Enough of those and you get massive recall.