I have a 1989 RS with a 2.8 litre V6, the problem is my fuel economy is horrible as of late. I am going through a lot of fuel and I am wondering if anyone can give me some ideas as to why. I am wondering if it could be a faulty cold start valve? I should also point out that sometimes my car takes a while to start and other times it starts right away. I am wondering if this is a clue to what may be the problem.