The reality of it is
you can only tune out so much at idle
It is possible to have too much injector or over injector
As the motor cannot physically use that fuel that early and or air is not moved soon enough
I did a car for someone with a stock turbo/intercooler stock motor setup in a gn years ago
It had the trans done and later we put a what we thought was a converter in it lol
On a 255 6015 drag radial on the stock rims with a 3.70 rear gear
pump gas alky car and it was nice to drive and ran...