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

[Ryo]

Ok i have verified timing and all is lined up no issue there. I skipped the other things you mentioned and went straight to measure fuel pressure because i buyed a new compression tester and fuel pressure tester. I measured the fuel pressure exactly according the manual at the point where cold start injector is connected. I performed the first measuring according the manual with engine OFF just letting fuel pump work. The result: 15PSI ( about 1 bar of fuel pressure) according manual if i remember there should be 33-38 PSI (2.5-3 bar's) so i might have figured out why the engine is not running properly. I measured the fuel pressure with engine running and the result was the same. So i guess the old fuel pump from AE86 (oem toyota) that was working before somehow started to fail not sure why because it was working perfectly in AE86 before. I went to my local parts dealer and picked up some magneti marelli pump that pushes 3bar (95L/hour) that is the same spec as the oem one. It was for a good price 40 euro (compared to others around 130 euro).
So now i am waiting to install it and to see if the issue will be finally solved.
Will inform you about the result.

Forgot to mention i already tested second fuel pressure regulator that is good and verified all lines for leaking but no issue there so it all points on the fuel pump.