W201 AC issue

I wanted to check to see if anyone could help with the hesitation and stumbling problem. This ia a 91 190E 2.6 having the problem. Start up is fine and taking off is good, but if you turn the air conditioning on after start-up and they try to move out it will hesitate & stumble. If you step down rather quickly it will die out. It could do this a couple of times. Once it's going a ways like a block or two with the AC still on and stop and re-start there is no problem. I've read a lot of problems with the threads on Climate Control, but didn't know if this was a possible cause or not. The R-12 is ice cold no problems there. The cooling from the R-12 refrigerant is hard to beat, I think. Any help to trouble shoot problem would be appreciated. Thanks