Fuel cap problem

[Mark Norton]

Bongo is running very well with no apparent problems as long as I do not tighten up the fuel cap!

If I screw the cap down then I will conk out when going up a hill or when accelerating hard. Releasing the cap lets out the vacuum that has built up behind it.

Been driving like this for 2-3 years now and it's not a problem, but is this normal?

[wonkanoby]

its common

clean it as its little breather hole is blocked

[Hollis]

Hi

Is that on a petrol or diesel?

Derek

[Simon Jones]

I believe Mark has a diesel . My observation from owning both types is that the diesel tends it run with a slight vacuum in the tank which is why it's important the breather system is in working order to avoid fuel starvation. In contrast, the V6 petrol runs with pressure in the tank which is why you get a noticeable rush of air coming out when the filler cap is removed. This appears to be normal operation.

[brorabongo]

I had noticed the same myself, so I took the cap apart. Cleaned it but did not make a difference so have been using the cap without the spring/flap since. Running with it for over a year now with no problems.


http://www.igmaynard.co.uk/bongo/forum/ ... ap#p427070


btw I never have a full take of fuel so don't know if it would leak if so.

[ELZE]

Cut the hassle out of ya life man and buy a new one. I got a locking one from Ebay, works a treat!

[Northern Bongolow]

the tank itself has a breather system someone put up some lush project pics up on a thread a while ago.

the breathers are clipped to the chassis, if it ever stops raining have a rummage.
undersealing etc can block or restrict them.
the cap alone cannot cope so these are needed,

[longhaul8]

Think this maybe what Ady is thinking of

http://lushprojects.com/bongopartsmk2/c ... mgno=.html

[longhaul8]

And this is the topic the pic was taken from so may just help.....i hope it does

http://www.igmaynard.co.uk/bongo/forum/ ... er#p534423

[Northern Bongolow]

cheers mate, , honest im not lazy, just hate puters.

[longhaul8]

do you a deal you stick with the oily bits and i will try and keep clean using the puter

[teenmal]

the tank itself has a breather system someone put up some lush project pics up on a thread a while ago.

the breathers are clipped to the chassis, if it ever stops raining have a rummage.
undersealing etc can block or restrict them.
the cap alone cannot cope so these are needed,

Hi,
On a Diesel vehicle the tank is vented by a breather pipe from the tank to the neck of the filler pipe,if you remove the cap you will see the aperture for the pipe,any venting lower that that would result in an expessive leak.

[Northern Bongolow]

so is the link above posted by my puter expert buddy for the petrol.

[longhaul8]

Ady made me do it

[teenmal]

so is the link above posted by my puter expert buddy for the petrol.

Hi,it does not matter whether its Derv or Spirit (petrol) the breather will always vent higher that the tank,usualy the neck of the fill pipe.

If you look at a garage(petrol station) forecourt you will see the high vent stacks,you also get some that will be connected lower,this would mean that they are using Stage 2 Vapour Recovery.(Just a bit of useless information)

Cheers