B16a2VTIguy

I have discovered a knocking/diesel type noise when ticking over. my car is a civic vti it has the B16a2 engine in it, and it runs fine otherwise, its not the big ends or the little ends, so i'm wondering could it be noisey injectors? its not as such a knocking noise is more like a clog-clog-cloging noise...Its hard to explain!! the noise will stay untill i get to about 1500rpm then it disappears, its also more noticeable when i'm inside the car. It also makes a tappet type noise but i have checked and adjusted all the tappets and they are ok, so could this be the injectors?? Also has anyone got any B series trannys ther selling (hydro) thanx for any help