i have a 88 n/a with a 91 n/a motor. the front cover was swapped to retain s4 wiring and omp.
so my car runs lean from 4k up it will make it up to redline, but it hesitates badly.
i have an safc that i am using to adjust the fuel curve, and i can get it to run better if i add 15-30% more fuel in the upper revs in a linear fashion.

now my last engine had low compression but was also an s5 and never had this issue.
so what could cause this then? i know my injectors are all good i sent them out to be cleaned a while back and they did just fine in my old motor.