9mm vs 11mm pumps

[n0v0s]

To save me making a new thread and to get this rolling again...

I appear to have a chronic lack of fuel in the upper revs recently. I used to pin the 35psi gauge easily and hold it with my 9mm pump. Now I can peak 28psi at 3k rpm put this dies off rapidly to under 14psi by 4.5k rpm+ on straight derv :/

I've changed my inline fuel filter, checked tank pickup, no air ingression I think, lda pin isn't jammed, no boost leaks and it still does this with an mbc so can't be waste gate?

If the turbo was on its way out, would it ever loose ability to maintain boost or does this point to vane pump issues

. Everything else under 3/4k rpm is fine and normal so i think it's the waste gate blowing open on the k14 at higher rpms