These are the symptoms I had on my 1995 850 turbo. Car would stall a few times a day whenever I slowed down for a turn, or sometimes a stop sign. Note: no indication from the engine of sputtering, no hesitation, just completely died, and would start easily and no problems for next 20 miles or so.
Since relatively new to the area, I took my car to two foreign so called experts and neither could duplicate the problem or find anything wrong with the system.
A third mechanic, who works strictly on Volvo's indicated that the problem cannot be seen with the car computer, but a hook up to the Volvo computers online indicated a camshaft sensor was the problem, and after replacement , has never been a problem since.

 

I had a very similar experience. 850 NA dying very occasionally when slowing down at a stop sign. Then it started lurching while I was driving at freeway speeds. I replaced the fuel pump relay, the fuel filter, then the fuel pump (mercifully, that was $9 at a U Pull R Parts operation). Also cleaned out the air intake and the MAF sensor. Nothing changed until I replaced the camshaft position sensor. Mine looked somewhat scorched. Haven't had the stall-out problem since. Of course I'm not saying this is your problem, but it was surely mine. Good luck.

 

Henry10 the battery is nearly new and charge is good, I did as you suggested and the connections are good the vacuum lines have no leaks or breaks the car have been taken care of very well it only have 152k miles. I did replace the oil cooler lines and the mechanic did a tune up and the air filters are good the gas pump pressure is 50psi. the only thing I can see now is that fuel pump relay ($65.00)

 

So if u are having this problem the best thing to do if availible is drive with a fuel pressure gauge see if it drops while driving. Due to many of these problems can be the reasons but the main are fuel pump relay,fuel pump,cam position sensor,and injector relay located on fan .all these will cause simlar problem its just checking and eliminating thst needs to be done.

 

I know this was years ago BUT My Elderly Mother has a 94' Volvo 850 and it's been doing the EXACT same thing for the past 10 maybe 15 years. At first it was not a problem it only did it maybe once every month or so BUT NOW almost other time She drive it. When she was younger it wasn't so much a problem but now it scares her to have it die in Traffic. It only happens when she either Stops or slows down to Stop NEVER while Driving.

We had taken it to the Local Volvo Dealer when it first started and they replaced the Cam sensor which seemed to help for Hmm a week. Then they just shook their heads and said that " They needed to see it happen" so they kept it for a week and drove it everyday and NOTHING happened. I don't know what they needed to see, the car just Dies like it ran out of Gas all the panel lights come on and She has to pull to the side of the road.

When this first started happening the Car would start right back up then it took a few try's now it takes a min. or so and like I wrote it's happening more often.

I've offered to Buy Her ANY CAR she wanted So has my Sister's and Brother BUT she doesn't want a new car she LOVES Her Volvo and to be Honest so do I it drives GREAT , has GREAT PICK UP I even own a S70 which I bought because of Her Volvo.

Finally this Car has been in the Garage more times then I can count and They say anything to Cam Sensor to Fuel Pump to Battery to Relay So to put it plainly THEY DON'T HAVE A CLUE. BUT they are Thousands of people writing on-line with the EXACT SAME problem with the 850 HAS NO ONE figured this OUT?

If anyone can help PLEASE DO SO ASAP as I'm getting really tired of having to drive 40 miles each way to take my Mother to the Store or Doctor appointment because she afraid to drive her car. HELP in the name of GOD PLEASE HELP!!!!!!!!!!!!!!:

 

If I were going to fix this, I would want to get the car from her and drive it myself every day for a few months. If it dies on you a dozen times you will have a chance to make some observations. Is that an option for you?
If it turns out it really only dies once a month, then you might have a to keep it a year. I am an engineer so I may be taking too realistic an approach.
If you are willing to do that you can find out quite easily whether fuel pressure is an issue. Quite easily. You will have to attack that in the moment. The on-board diagnostics thing also can tell you whether or not the cam and crank sensors are answering back, and again, you'd have to attack it in the moment.

 

P.S. If you just want additional part replacement ideas, the ones in this thread are pretty good.

 

I have a volvo XC90 2005 model but I noticed it dies while am driving I have changed the pump also the censor the problem still continues,my engineer recommended that I changed the fuel filter under the driver side haven't done that yet pls I need help.after some minutes it will start and fire very well.i don't know what could be the problem I love the car so much but this issue is not making me to enjoy the ride.iduh

My car always dies when am driving pls I need help I have changed the pump,censor and other services but it still happening.