consistent surging when A/C is on...

Today I noticed that when I'm going at a constant RPM (normally about 3000) and throttle (about 16-20%) with the A/C on, i'm getting what feels like a mild lean-surge.. It'll slow down for 1-2 seconds, then go back to normal for 2-3 seconds. It's happening in every gear and every A/C setting (other than 'off') and really has me puzzled.

I took the car out for a 20-mile ride with my laptop and OBD-2 gear hooked up, recording the ride. I recorded nearly every sensor (except for temperature and other unrelated stuff)... The only thing I could see that lined up with the noticeable surge feeling was a 5-8% lean-fluctuation of the fuel trim. When the surge was not felt, the fuel trim adjustment was only in the 1-1.5% range.

Looking at the O2 sensors, O2 sensor 1 fluctuates a lot - about every polling interval (about 1.7-1.8 seconds), the sensor would fluctuate between a reading of about .1v and .8v. The second O2 sensor was staying near-constant around 0.7v. The readable range on this OBD2 software is from 0.0 to 1.0 volts... Does anyone know which side of the spectrum means 'rich' and which means 'lean'?

The car is a 2000 Integra GS-R that's stock (other than the AEM intake) with 51,000 miles (JUST out of warranty). It rained for the last 10 days straight, finally getting sunny today. I didn't notice this problem when it was raining, but did notice that the power felt a little lumpy under heavy throttle (with the AC on the whole time). I figured I was just slipping the tires a little in the rain...

My only other thought is that the A/C compressor clutch could be malfunctioning and switching itself between clutched and de-clutched every 2-3 seconds. I haven't noticed it doing this during the surges, but then again it's hard to listen for it when the engine's at 3000-3500 rpm!

Anyways... Any thoughts on this phantom problem? Thanks in advance.

i think its just the clutch coming on and off, but it shouldnt be going on and off every couple of seconds like that, my advice would be to find a new guage cluster with fewer miles on it, and then bring it back to the dealer.

my civic hatch started doing the same exact thing you described today:confused: If you ever find out what it is let me know also.....

Actually the temperture sensor reading will help a little, but from your first O2 sensor (closest to the engine) seems like there is something causing the ECM to really leaning the maxture. Were the readings done while the engine is warmed up?

what is the MAP sensor reading?

Did you mean the RPM dorp or the speed slow down when you said "It'll slow down for 1-2 seconds, then go back to normal for 2-3 seconds"?