I have a 2000 civic EX. I just bought car a month or so ago.
The car idles too low when the AC is on, to the point where the compressor does not operate correctly. The compressor makes "hiccup" type noise/action when the engine comes back down to idle. I know the AC system is charged correctly, I'm convinced it's an idle issue.
I've read I should be around 810 RPM at idle with the AC on and around 670 RPM with the AC off. I'm guessing I'm only around 500 RPM currently with the AC on.
I'm going to take the IACV off and clean it first. My question is if that doesn't work what should I do next? I've read that it could be the ECM not communicating with the IACV to increase idle when the AC goes on.
If you're guessing at what the idle is I assume you have a DX with no tach?
Check all of your grounds, make sure they are clean and well connected. If not that, try kicking your idle up a little, if you don't know how to do that, I will post pics later but I'm at work right now and don't have access to it.
The idle seems fine with the AC off it's just too low with the AC on. I've got the factory manual and know how to adjust the idle. I'm just concerned with adjusting the idle if it's fine with the AC off.
I'll try and get some more accurate data on the what the RPM is at idle both with AC on and off.
does the condenser fan come on when you turn the A/C on? take a look.
what happens is that the pressure goes high from lack of air across the condenser tripping the pressure switch and cutting the system off. then the pressure normalizes and the system cuts back on. off. on. off. on. when it is on it loads the engine more than usual, causing a low idle.
you're A/C should still work fine cruising down the interstate but lacks cooling below 45mph and idles funny sitting still, cutting the compressor on and off.
i've discovered the same issue with my '96.
__________________ I still work on cars sometimes
"Leave me alone, I know what I'm doing." Kimi Raikkonen
"cowards never start, the weak never finish, winners never quit."
Honda and the Honda marquee are registered trademarks of the American Honda Motor Company, Inc. Neither American Honda Motor Company nor its subsidiaries or affiliates shall bear any responsibility for Honda-Tech.com content, comments, or advertising. Honda-Tech.com is not affiliated with American Honda Motor Company in any way. American Honda Motor Company does not sponsor, support, or endorse Honda-Tech.com in any way.
Copyright/trademark/sales mark infringements are not intended or implied.