I have a 95 Volvo 850 turbo wagon with somewhere around 160K miles. For the past two years, the old gal has been stalling on me. First it was only when I was stopped at a light or driving low speed. Then it started when I was on the highway upto to speeds of 55mph. I’ve taken it to a mechanic at least twice and no codes are thrown by the computer. It only seems to happen in the summer. I’ve never had it happen during the winter. I live in DC so it gets humid in the summers and I think this may be related but who knows! It could be particulates in the air interfering with the air induction. Or maybe its the fuel delivery. Or maybe its spark. I replaced the spark plugs wires and distributor cap and rotor last year. Anyone got advice?