stalls while driving on 1994 Volvo 850

My car will just stall while driving. Not at a stop, but as I am driving down the road. What could this be?

Asked by for the 1994 Volvo 850
On the stalling issue I would suspect the fuel relay is dropping out at times. Read the previous writeup about stalling I described how to change it.
3 more answers , 1 more comment
my 94 850 wagon hard to start after sits over night then stall in reverse and sometimes while driving
yes it always restarts and does fine rest of day .no i did not check codes no check engine is not on.
This can be caused by several things. Is your check engine light on? Have you checked the trouble codes? Does it always start back up after stalling?
yes with a red lighting bolt in side of two red lines