89 Civic Si idle problem

[redline1219]

I have an 89 Si and sometimes mostly in cold weather, it idles funny. It'll go from about 2k for a sec, to 750 then all over again. Sometimes itll do it all day, and sometimes it wont do it at all. When I drove the car in Phx for a year, this never happenened. Ive been told by some people that it could be IAC, but I dont know for sure. Do I have to replace the the whole valve or is it something that could just be clogged and I could clean it... Thanks for your input...

 

[91CRXSI]

Originally posted by redline1219@Feb 16 2005, 12:26 AM
I have an 89 Si and sometimes mostly in cold weather, it idles funny. It'll go from about 2k for a sec, to 750 then all over again. Sometimes itll do it all day, and sometimes it wont do it at all. When I drove the car in Phx for a year, this never happenened. Ive been told by some people that it could be IAC, but I dont know for sure. Do I have to replace the the whole valve or is it something that could just be clogged and I could clean it... Thanks for your input...

[post=461575]Quoted post[/post]​

Sounds like it has an erratic idle, first check all your vac. hose routing and diagrams, also inspect them for holes, not sure about the cold weather thing. after checking your lines then move on to something like the IAC

 

[CRXSI91]

sounds like a PCV valve..my old crx did the same thing..the idle wouldnt stay in one place...check the PCV first..its only like 3 bucks...then after that,check your IACV,and your vaccuums

 

[brian11to1]

To check the IAC pull off the intake hose or tube and plug the two holes inside the throttle body if it stops surging then that's the problem replace it.