I have a 97 LX with 140000 mi on it. Recently when I come to a stop sign/light the engine starts konking out. It sounds like an old car that keeps running after you turn the engine off. I guess you could call it a "ka-chunk, ka-chunk..." sound. The engine is definitely struggling to keep running, but it does. This only happens with the AC on and it stops once you turn the AC off. Also if you give it a little gas it starts running fine again. The problem is intermittent. I drove it around today with the AC on and it ran like a dream. It seems like once it starts it doesn't go away until the next day.
I took the AC belt off this weekend and the idler pulley and the compressor pulley/clutch plate seem to spin smoothly.
Any suggestions
Thanks

 

Check that the condenser fan works. Failure of the fan will cause excessive pressure with the car sitting still, making the compressor load down the engine.

Clean the IACV. The engine needs extra air to maintain idle speed with the A/C on. Along those lines you could also try opening up the idle air screw some too, though that may make the idle too high with the A/C off.

 

The condenser fan looks like it is working. I'll check the IACV tomorrow. (gotta go to work)

 

I know this is a little old but I didn't want to say I figured out what was wrong until I knew for sure

This problem was either low coolant in the radiator or a broken radiator cap (or both). I guess air in the coolant system can cause problems with the idle. It was a nice change to have an easy fix.