Fuel in oil

Does any one know why fuel drains into my valve cover from the fuel meter. There is a fuel pressure regulator or filter type device on the side of the fuel meter. It has a small hose leading to the right side valve cover. As soon as my engine warms up the fuel starts to flow into the engine. There is a spring inside this device so maybe it regulates fuel pressure or prevents vapor lock. Is this normal? Also, what is this device?

David
88 560 SEL