You may want to look at your first post, there is the same answer I am posting below. You may not like that answer but you did get one. Sorry if you didn't like it.
It actually is more likely that the pressure regulator is at fault and leaking internally. That causes a large decrease in mileage. There are a few tests that would pinpoint it and they are all covered in the service manual you can get an electronic version at www. Eautorepair. Net
Have a nice day.
Sunday, December 14th, 2008 AT 9:27 PM