This is the most common problem I've had with this car. Make sure there is the small 'ground strap' from the fuel line to the body. Its has 2 small clips on it. If your missing this, I made one using a wire once & this worked for me. Anyhow, it sound like your float might have a tiny hole in it & it has gas inside of it. This could be anywhere on the float, especially around that clip that hold it in place. Better off just replacing it with a new unit. Just like the guys said above, listen inside it to hear the contact rubbing the inside in both directions. One final thing, is your voltage limiter behind your cluster a good one?