4age hitting gas too quick means engine stalls - what is the issue?

[Ryo]

Hello
I am unable to figure out what can be the issue on my ae92 with early tvis red top 4age engine with AFM. I know i got fuel i got spark and when i start the engine it revs with about 1500rpm cold. But this all not matter as i am not able to get the engine to higher rpm quickly hitting the gas i can do it only very slowly. Hitting the gas too quick means engine stalls and mostly dies. Am i looking for a vacuum leak or air intake clogged? I don't know which things actually affect this. I asked on boards elswhere and studied manual measured things around checked hoses but no luck. This is one tricky issue. Anyone has some idea where to look. AFM looks operating normally and throttle body was cleaned as well last time.
Thanks for any hints. Ryo.