Car is a 91 CRX Si, B16A, PR3 ECU.

Just yesterday I noticed that when my car gets warmed up it idles at 800 RPM for a second, then drops to about 400 RPM, then back up to 800 and just keeps repeating til I give it some gas. It also does this when the car is cold, but it always went away when the car wamed up, until now. I have checked the vaccum lines, reset the ECU, disconnected and reconnected the EACV, and it's still doing it, I'm also not getting any CEL's. Does anybody know what could be causing this?

Thanks in advance.

 

Might need to check for low coolant or air in the cooling system.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crex23 &raquo;</TD></TR><TR><TD CLASS="quote">Might need to check for low coolant or air in the cooling system.</TD></TR></TABLE>

If you're not getting a CEL for the IACV, I'd bet this is the case as well. Or you could just try cleaning the IACV with carb cleaner while you're at it.

 

I have the same problem and believe it to be air in the coolant lines...haven't really had time to check it out yet though. Just need to purge the coolant system of air and check it out.

Let me know via PM or this thread how/if you ever fix your problem, because I have the same issue!

 

check out some of the other idle problem post. i posted what the problem 9 times out of ten is and how to fix it.