Leeroy_25

I have finally got around to playing with my pump settings on my 20B and got it pretty sorted.. So very pleased with that. However, I have one issue I have not resolved yet and I am not sure if it is pump related, general map or other? Can someone give me any pointers please?
So when I pull off my fuel no longer leans out like it did before. However if I am stationary or rolling and jam the throttle very quickly the fuel leans right off to the point the engine momentarily dies and picks back up if you maintain throttle or lift off.. So you hear the gasp of air but clearly this is not backed up with fuel.
The map appears to dart along the 1000rpm line (idle is 1150) to 0Hg as you stab the throttle. I tried adding some fuel in to the 2HG and 0HG but didn't seem to have a noticeable effect? Also tried adding a bit on the 1500rpm line with little to know impact. I don't want to get to the point it impacts my low speed cruise AFR.
So my question is whether this is a pump setting issue and I need to the pump to pulse longer or essentially over inject fuel when it triggers? or is it a case I need to play with this map area on the dyno and see if I can comprise a reasonable slow cruise AFR and overcome this?

If there is another setting I have missed all together please let me know.

Let me know your thoughts.

Thank you
Lee