Hey guys, got my lil Honda working again. Im glad its finally running without stalling. But now, I have another small issue. My car seems to run perfectly without the A/C running. No jerking and no rough idle. BUT, when I turn the A/C on my idle fluctuates. It dips down to almost stalling and will then blip back up to normal repeatedly. The minute I turn it off, it runs fine.

So, I already know that it might be my IACV or O2 sensor that may need to be replaced. I took it to auto zone to see if more refrigerant was needed but the needle on the gauge pointed to MECHANICAL PROBLEMS. The IACV is like 210 bucks..money I don't have right now. =/

Would cleaning the IACV resolve the issue? I know that the location varies on A/T and M/T cars. Mine is a M/T. Where is it located? I heard it was near the throttle body...correct?

 

Does the condenser fan work? Does the air get cold if you turn A/C on while driving?

Cleaning the IACV is never a bad idea. But if you have excessive pressure in the A/C (typically fan failure, or overcharging) it will overload the engine at idle. To properly check the A/C pressure you use a set with two gauges that measures in psi. Don't let one of those crappy color coded single gauges anywhere near your car.

 

What year/engine?

Also, any CEL codes?

 

You know what? I drove my car home from work yesterday (5pm) and had the A/C on MAX. Poor thing never stopped blowing hot air...even after I got onto the expressway. It used to be that when I would get the car moving on the highway it would eventually start to throw cool air. But yesterday was just hell!! I eventually just shut off the A/C and rolled my windows down. I figured if it had something to do with the freeon or compressor I would probably end up blowing it if I let it run like that.

So I should check out my A/C pressure again with a better gauge? I'll try that today to see if it makes a difference. Thanks

 

The car is a 1999 Civic LX with a manual tranny. I believe that the engine is a D16Y7.

I DID take it to auto zone and the first thing that popped out was the o2 sensor. However, I had just gotten back from an outta town trip a few days before (which was when the CEL turned on) and the guy said that usually the o2 sensor will show up because of the change in altitude between cities and such. So he reset it but nothing else popped out. He told me that it was very possible that it could be the IACV and that I should have it replaced.

The CEL was off for the past 2 days but this morning on the way to work, it showed up again. So now I'm thinking I'm gonna try to clean the IACV (which i've located finally) and see if that helps. If not, then maybe it's the o2 sensor that needs to be replaced? I just dunno where to find it on my car. And I guess I'll also check out the level of refrigerant on my car to see if it's not overcharged or not undercharged.

Thanks for replying btw

 

Don't replace anything yet. Definitely check the items mk378 mentioned.

Did you write down the exact code (e.g., P0135) that was pulled? Click the CEL link in my signature to learn how to pull the simple OBDI code yourself at home using a paperclip or short wire. Post what you find.

 

Thanks Ron! I didn't get the exact code that was pulled. But today the CEL came on again. I'll head over to auto zone and then get the code that was pulled. I'll also try out to see if the compressor is overcharged or undercharged and clean out the IACV. I hope that does the trick. If not, I'll go ahead and post up the CEL code that I pull from the device.

I'll keep you guys posted. Thanks again!!

 

So here's the update guys:

Looks like I've figured out the root of the problem. Sure, the car works and idles fine without the a/c but with the a/c on the car would spaz out with a fluctuating idle. I had cleaned out the IAC and was still having the same problems...

I popped the hood yesterday and was watching what happened when the a/c turned on. This is what I saw: A/C turns on BUT the a/c condensor fan DOESN'T. Eventually when that fan should kick in, it doesn't therefore causing the idle problem and making the belt make a loud shrieking noise.

I lightly tapped the fan with a tool...and it started spinning. It seems to be that the fan doesn't have enough power to start spinning on it's own maybe due to the part being pretty old. Once it started spinning, the idle worked just fine and the a/c began to blow cold air once again.

It looks like this problem is solved. The fan is $130.00...not too bad. Hopefully I'll have the part replaced by this friday. Thanks to everyone that looked at my post and lent me so helpful advice. =)