Weird problem under heavy throttle

[talon_frost]

OK here is my problem...my 90 tsi awd needed a new ecu, so my friend gave me one but it was from a 93 tsi awd,i swapped the correct wires the car will run and it does,but here is my problem. When i drive normal "not hitting boost" the car will run fine. But when i give the car heavy throttle the rpm gauge will accelerate normal until it hits 3500 RPM then it will go up and down from 3500-RPM to about 2500-RPM .also along with that the car will not accelerate at all it feels like bogs to the extreme. I have checked for boost leak and there was nothing leaking at all...Now i am running 15psi on brand new stock fuel pump but I have also turned the boost down to 9 psi and the problem still stands....i've changed the fuel filter along with the air filter.....any suggestions???

 

[CTP]

Jumping tach and no acceleration past a point = ignition problem

 

[talon_frost]

well the ignition is fine because ive checked and also the car will idle and run fine until i hit throttle

 

[CTP]

The ignition tends to die under load because that's... well... that's when there's the most load on it. Aside from any obvious ignition problems, you most likely wired something wrong or that ECU isn't compatible, but I don't know much about that.