'79 CJ5 gasline question.

Hi all,

it seems that if my '79 CJ5 is sitting for a while that the gas
runs through the line back to the tank.

That means that after it has been sitting for a while. I have to crank
it for a while before it starts. (if it sits for a day or so.. I have
to crank it quite a bit. If it sits there for an hour or 2 there's no
problem

I replaced all the hoses.

How does the gascap work ? is it supposed to seal the gastank,
or doesn't it matter ? The gascap I have is probably the original.


thanks,

Ron