[djed]

Ongoing problem - After filling up the car with a full tank of petrol and doing a long trip on the highway and using about 3/4 of tank the car sometimes sound like it is starved of fuel and splatters.
When it first did this, I pulled over and I noticed the tank has sucked itself in a bit. As I took the petrol cap off I could feel suction on the cap, until the cap is off, then the tank makes a noise as it re-expands. This has happened about 10 times and every time it happens the tank is sucked in and by taking the cap of it fixes the problem.

Any ideas for a fix?

I am assuming some type of air intake for the tank is block. Where does the tank normally suck in air to replace the volume of fuel that the car uses? Cap, charcoal filter intake?

[joeblow]

Charcoal canister is blocked.

[caboose]

sounds like you may have a blocked breather line. it will be one of the small pipes going to the fuel tank

[djed]

yeah one of the previous owners had removed the charcoal canister for a dual battery tray and block off the pipe.

So does the charcoal canister's valving allow it act as a breather as well as a vent fumes?

[christover1]

djed wrote:

yeah one of the previous owners had removed the charcoal canister for a dual battery tray and block off the pipe.

So does the charcoal canister's valving allow it act as a breather as well as a vent fumes?

Yes, it allows air to get in tank as fuel is used.

Needs to be there.
but as a temporary fix, leave cap loose.

[Goldnomad]

christover1 wrote:

djed wrote:

?

but as a temporary fix, leave cap loose.

I've had this problem for a couple of years on my Vitara.
I leave the cap loose as suggested.
I've checked the charcoal cannister and it is fine.
Just too mean to buy a new cap

[djed]

i will defiantly try to chase up a second-hand charcoal filter. Anyone is Brisbane have a spare?

do some Suzuki fuel caps have vents on them? the springs on mine do look pretty rusty and there is dint in the outer rim of it. I see Suzistore sells spare ones. Do you think a new one will help?

[christover1]

djed wrote:

do some Suzuki fuel caps have vents on them? the springs on mine do look pretty rusty and there is dint in the outer rim of it. I see Suzistore sells spare ones. Do you think a new one will help?

My old 1.0 litre had a vented cap, but doubt it was factory.
it would leak out fuel on steep side slopes.

But a decent vented cap would help.

[jason_sgt]

My Vit used to do this... Until I took a chunk out of the tank, solved the suction problem Curiously, the new tank doesn't do this, but when I undo the cap there is a vacuum as the air enters the tank, making me think that the problem may re occur. Be keen to know what fixes your issue.

[Goldnomad]

Start with a new cap.
If it still plays up, PM me and I'll send you the instructions on how to test your charcoal cannister.

[djed]

yeah might try new cap first and then find a charcoal canister and plumb it back in to where it has blanked out.

it would be good to find a fix. i think the tank is about 8L smaller due to being sucked in so often.

[djed]

actually i had a look at my fuel cap and i do not think the design has provisions for letting air in, only air out.

It looks like as pressure build in a tank it will push on the spring and as a result will slightly lift the cap.