gas cap for Ka24de 510?

[my_fiveten]

do i need to change my gas cap since my motor is fuel injected? i am using an external fuel pump. there is alot of air pressure when i open it up after using up all my gas. thanks

dennis

[SRFiveTen]

i run a vented lockable cap on my ride, but the cap often hissed at gas pump,,, so, since i junked the evaporator gadget under my rear package tray, and a hose from the filler neck tube to the gadget became available, i attached a short hose with pcv valve and k&n filter to aid venting.

can't remember which way the valve acted, i think it is allowing the air in, but restricting the fumes & fuel to flow out.

since this little ethnic engineering was performed, the hissing of gas cap at pump has gone away.

[JonCarson]

Isn't the hissing of the gas cap when you open it normal?

The cap on my stock '90 240SX is original and it's always done that.

The gas cap on every other car that I've filled with gas has done that too...