Volvo 850 1993

At random times this car will just stop, like it has run out of gas (though it hasn’t) we have had it checked and checked, they can’t find anything wrong with it. Fuel pump? seems ok, and it only happens at weird random times while driving in gear. Thoughts?

When it ‘seems’ to run out of gas, remove the air filter and spray some starting fluid into the air intake.

If it fires up then dies you have a fuel supply fault and somewhere to start.

Will it just restart after some period of time? If so, how long? How often does it happen, x miles or every y number of days, etc.? Under what conditions does it occur? Any computer codes? Check engine light on or off?

Check the relays for the ignition and fuel pump. The ignition switch is also suspect. More than likely the problem is electrically related. It would help to know any more clues when the trouble happens along with if the ignition is working or not or if you can hear the fuel pump when you turn the key from OFF to RUN.

When the engine SUDDENLY cuts off, that’s that’s an electrical / ignition problem. If the engine stumbles, and then dies, that is probably a fuel problem. Which happens?
Change the fuel pump relay. Drive it awhile to see if there is a recurrence. If there is, the next steps will depend upon whether the failure was sudden, or staggeringly.