...BTW your Bieber avatar is awesome.-Malone
Although, regardless of the line length you'd think that since you're moving a non-compressible fluid through the line and, providing there are no air bubbles, should get injection and pressure when required.
I've got three good ones sitting in my Garage, I'd be willing to send to anyone who wants them - for shipping cost. Trying to clean out my garage...(the forth one (cyl #3) has a small leak)
That pressure "wave" takes time to travel through the line. Even though the fluid is not compressible, it takes a few milliseconds for the pressure to reach the injectors once the pressure is delivered on the injection pump side. Milliseconds can translate to significant differences in degrees of timing when the engine is actually running.