my car idles up and down and kinda high when the engine is cold then drops to 500 when it gets to normal temp.

its a 96 civic ex y8

i tried taking the IACV off and cleaning it which seem to help for like 2 days. someone told me to check this out http://honda-tech.com/zerothread?id=1564019 but it says 96+ dont have that.. anyone got an idea?

 

check to make sure your coolant if full
pcv valce could be gummed up
if it runs like ---- cold and runs good once warmed up then its prob your coolant temp sensor on your head

 

ive been dealing with this for a while. i swaped out the coolant temp sensor from a 98 ls motor i had sitting, looked the same, not sure if they are, didnt fix the prob so i switched back (anyone know if there supposed to be interchangable?)

my pcv is drilled out but it was doing it before.. there is no vacume to my pcv its just drilled and vented to the ground, my catch can vacume source sucked and i gave up

 

if it fits then it'll work, honda sensors have been the same since atleast 88 - 2000 some difference but mostly the same (in electronics anyways).

check coolant level like he said. could also be a bad IACV, that controls cold idle and if it opens, the closes all the time during warm up then it will idle up / down / up / down. etc...