Thinking of it another way, the DV's are not balanced as you would expect from six injectors pop tested to within couple of bar - how do we know the DV's are performing equally well....this is one of my fist YouTube videos which surfaced on an unrelated Google search.
The story behind this was trying to establish when number one pot was on injection stroke, marked the aux belt with paint 15 degrees ATDC..
..hey, don't laff it worked ..
https://www.youtube.com/watch?v=SQ5KIgWatJk
One way to check your DV's..