I got the b16a in my 96 EK for a coupla days now. it drives good EXCEPT for a stuttering problem around 1500 rpm. If I were to give 40% or more throttle it revs up good but under light throttle conditions the rpm jumps from 1500 to 2k and to 1500, the only way to go around it is to give it more throttle. ????? anyone know what might be the cause of this?