My civic been breaking up like it's in 2 step people are telling me it can be my iac valve any info on this ? Any other suggestions did full tune up and changed distributor . Happens at any rpm 99 civic with 99 spec b20 high comp with low intake manifold . Also my rpm fluctuates and idles REALLY low

 

iac wont do this.

you need more fuel if the timing and valve lash are good

 

Sounds like lean run to me. Time for a retune.
Regards
Dave