hey guys ive got a high comp setup in an r31, everything is setup pretty much stock, stock exhaust, intake, afm, turbo injectors + turbo ecu, crossoverpipe.. Its running so rich that it seems to run better on regular 10% ethanol than it does on premium? Im getting black soot on my car too... I dont think its a boost leak so seeing its a stock setup what can cause it to run rich?

clean ya injectors mate