ac off car stalls ?

The only thing that comes to mind is the AAC (I think that's what its called) sensor on the back of the throttle body. I'm not sure what KA you have, but on the SOHC it screws in to the IACV valve plate that's bolted to the back of the throttle body and has a light blue plug on it.
This sensor raises idle speed when the A/C is on to prevent stalling. It sounds like your idle is set to low, and when this sensor kicks off dropping your idle back to normal it stalls out. Try raising your idle speed up a little bit (800-850rpm) and see if that helps.

Ya, you have something causing a poor idle. Like said above your car automatically kicks the idle up when the A/C is on preventing the stalling. Question is, why do you have a poor idle. There could be lots of possibilities. Id check a few routine items like fuel filter, plugs/wires, IAC, and such. Do you have any driveability issues like low power, stumbling, poor accel, or anything? As always you can consult a diagnotstic flow chart for poor idle conditions.

hey whats up i almost have the same issues that your having with my 91 ka. i replaced the iacv, the maf and a whole slew of other parts. I made a big mistake by not checking voltage on my batt, my alternator was bad. thus only having like 11 volts will make a ka run like poop. anyways check voltage always. who knows your alternator might be going out to. let me know if that worked or atleast helped:wazzup: