any air leaks??

are u still running the amal valve ?? or a bleed valve??

there so many things it could be, the best thing would be a rr session,

what ecu are u using?? i recomend the s1 ecu's as they dont retard timing like the s2 ecu's do,

i had same problem when i first bought mine, and it was the knock sensor retarding the ecu, so solved that buy buying a chipped s1 ecu