hi , does someone know if there is someting to tune if i hhave put gt2860 on my 1991 skyline gtr , since thaT , the car do not run good , on the ighway he always miss , what kan it be , my cylinder comp is ok , about 150 , i put 6 new spark plugs ngk heat8 , kan it be one or more injectors that is broken , ??? thanks for trying to understand my bad anglish