I have a 94 civic with a d16z6 and about 3 months ago i blew the head gasket. After fixing that it wouldn't idle right so i replaced the pvc valve, thermal valve, fast idle sensor, IAC valve and all my gaskets. It still does it when its cold and even warm. It will drop down to a real low rpm and then it will bounce up to like 1500 rpms... please help!!

 

i have the same problem in my d15y8 civic. my friend adjusted the idle and it went away for a little bit then came back. mine only does it ever so often. i would just take it in to the honda dealership see what they say.

 

vacuum leak?

 

Already took it to the dealership and the mechanic said it was that valve underneath my throttle body so i replaced it and it still does it.... no vacuum leak either

 

try adjusting your valves, i did and it fixed my problem

 

I adjusted my valves right after i put my head back on, i just don't understand what else it could be... thanks for these posts... any other ideas???

 

I have the same problem also.....I bled the coolant. And I unpluged the IACV and turned down the idle. mine goes form 1000 to 2000rpms only when it is warm. Once it warms up it starts to do it. The fast Idle valve is like a year old so I don't think it is that. Any ideas. If it was a vaccum leak I think it would do it all the time.

 

Take it to an authorized Honda dealer and have them fix it. They will fix it for you and it will be right, and if it's not, then you can go back and tell them to fix it again for free, because it should have been right.