One of the biggest benefit of fitting a aftermarket fuel rail claimed by the manufacturers is the GD models tend to have the problem of cylinder one running lean compare to other 3 cylinders, and the fuel rail will deliver exact the same amount of fuel to all four cylinders through the injectors thus eliminating the problem.

But it seems this problem with cylinder 1 (or cylinder 3 for GCs) is caused by incorrect readings as pointed out by Stace, so if you relocated the fuel regulator line to the centre of the manifold, you would eliminate this problem and save you alot of dole on buying the fuel rail......... good work Stace ....... I think you have way too much time on your hands

One question, if the boost gauge hose runs off cylinder one on a GD and the gauge itself is accurate and fast enough to register the fluctuations in the manifold pressure, would it give the impression that your car is not holding boost?