Just a bit of a query really - the Mazda seems to have a lot of vacuum in the fuel tank. At least, I think it's vacuum and not pressure.
When I take the filler cap off it hisses (I run my cars really low before refuelling - I know I shouldn't but I don't have much choice in the matter!). The Merc has done it a few times, but I took the cap off a bit too quick the other day and got a load of fuel down my leg!
So, is it normal to have such a pressure inbalance? Or do you reckon there's a vent that's blocked somewhere.
It's a carb-fed engine, and the only cars I've ever seen with pressurised tanks is fuel injected ones with in-tank pumps.
One thing I'm thinking it might be is the electric fuel pump return creating pressure - I'm informed by mrsigma that it's got a Facet red-top pump!
It runs OK but if it shouldn't be like this I'd want to fix it... any ideas?
When I take the filler cap off it hisses (I run my cars really low before refuelling - I know I shouldn't but I don't have much choice in the matter!). The Merc has done it a few times, but I took the cap off a bit too quick the other day and got a load of fuel down my leg!
So, is it normal to have such a pressure inbalance? Or do you reckon there's a vent that's blocked somewhere.
It's a carb-fed engine, and the only cars I've ever seen with pressurised tanks is fuel injected ones with in-tank pumps.
One thing I'm thinking it might be is the electric fuel pump return creating pressure - I'm informed by mrsigma that it's got a Facet red-top pump!
It runs OK but if it shouldn't be like this I'd want to fix it... any ideas?
