My mercedez 380 sl 1984 starts and stalls like every 15 minutes is it timing ? on 1990 Mercedes-Benz 300SL

I have no problems till I did a retrofit on the air conditioning . Now car stall every 15 minutes it is a 1984 Mercedez 2 dr. 390 sl gas. Someone says timing or an o sensor I don't really know if it is these things?

Disable the a/c and see if the problem goes away. that would be a starting point. Who was the retro-fit done by ? was the system evacuated and vacuumed down , before charging with R-134? Or was it already empty so someone just put fittings on and charged it?