i have a 96 civic with a b16 for some reason the idles fairly rough. i goes up and down and sometime when warming it up it completely shuts off. it also sometime sputters a bit while i'm driving. it usually takes a while before it'll finally start. i changed the plugs and i replaced the iac valve ( i thought that was the problem). I replaced the cap and rotor. Please help!!!!

 

Have you checked your coolant level and/or tried bleeding it recently?

 

It could be a few things. Is there a fast idle valve? If it has one, it could be bad. If not, then check for vacuum leaks and check to see if the throttle body gasket is leaking. (I got a donor motor that had a loose throttle body...similar problem you are describing).

 

i think the fast idle valve is blocked off with a plate but i'll check the throttle body thanks how can you check if it's leaking?

 

First check the bolts/nuts holding it on. Make sure they are tight. That gasket is really inexpensive. You could just replace it and see if it's better. If the t-body has been modified then it's been off. Could be a bad gasket.