hard to start in cold weather 2000 Beetle

Hello I hav a 2000 Beetle standard trans. I have been having problem starting my car in weather below 60 F since I bought my car in 03 it just does not want to start in cold weather witch 60 isn't that cold. I have checked the glow plugs glow plugs are good. I checked the glow plug relay that is good. I had the timing belt changed recently about 10,000 miles ago and had the fuel pump/injector pump replaced at the same time. I am at the point where I don't know what else to do and the dealership always says it is the fuel pump. So if anybody can help me I would be greatly appreciative.