At idle with the AC on the car almost feels like it's going to stall, whole car is shaking rpms drop to almost 100-200rpms.

Also with AC on at idle if I have the brakes pedal depressed rpms will drop, but sometimes when I let off the brake pedal rpms will climb a little, then I guess compressor makes the rpms drop again.

Any ideas?

 

your idle might just be too low.. adjust your idle air screw.. if that doesnt raise the idle a little your timing might be off.. also your idle air control valve might not be working properly

 

^^yep thats what i would say as well...my friend was having similar issues with his 97 eclipse gst and thats what i thought it was and i checked it outand sure enough with a little adjusting it idles fine now

 

IAC valve isn't doing it's job. The RPM should never change for more than a split second while the IAC adjusts to different loads on the engine.

 

Egr

 

don't post if you don't know what the fuck you are talking about. He doesn't have an EGR valve.

 

i vote for IAC valve too, mine used to idle low sometimes and stutter when i turned on the AC, cleaned the IAC valve, problem solved and havent experienced since. there was a lot of carbon build up when i took off the IACV

i wouldnt touch the idle screw before checking IACV though, since that seems to be the most common problem for poor idle

 

Yeah... I agree on the IACV. Here's an old thread on mine being clogged.

https://www.honda-acura.net/forums/s...d.php?t=217021

 

Alright got around to cleaning out the ICV and it was pretty clean. The screen part was clean as a whistle, the other side has some carbon but not bad at all. First spray with brake cleaner got it nice. I sprayed it again couple more times and liquid came out clear. So I air dried it for about 20 minutes. Reinstalled. Bled the cooling system. Was getting late so I just left it.

Drove it today with AC on and it's a little better. RPMs are normal with everything off, idles around 900-1000 when warmed up. With the AC on the rpms drop to about 500-600, but it recoves a little after about 10-15 seconds to about 700-800. When it drops still feels like it's going to stall.

Much better than before though as it doesn't stay in the rough zone as long. Anything else to suggest?

 

I worked on a civic with the same symptom. The AC condensor fan would not come on causing the system to overpressurize. The car would idle fine for about 30 seconds until the system built up pressure. The idle would drop and almost stall the engine. Then you could hear a clunk as the pressure switch turned off the compressor. And then the idle would return to normal. This would repeat itself constantly.

Hope this helps.