Miguel did pass the time by typing:
> My son's recently acquired '90 YJ (4 cylinder, 5-speed) has been
> smelling of gasoline, and a little checking revealed a broken valve
> tucked up inside the body behind the right rear wheel well. I have a
> factory service manual and have studied it carefully but can't figure
> out the purpose of this valve. It looks to be a check valve, on one
> side there's a line going to the fuel tank and on the other side
> there's a vacuum hose that runs up to the engine compartment. I
> thought mabe it was a rollover valve but according to the manual those
> are supposed to be attached the fuel tank.
>
> What do I ask for when I go to the dealer to get a replacement?

From what you describe that sounds like the line that vents the fuel
tank to the charcoal canister up front. It's a check valve that allows
fuel vapor to run up and get trapped in the canister. The vapors are
then sucked back into the intake when the engine starts.

Part of the emissions control stuff.

--
DougW