Volvo 940 stops and then restarts shortly after

need more info but sounds like a vaccumme leak or faulty fuel pressure regulater

If you need further help, reach me via phone at https://www.6ya.com/expert/james_9c1b039055413ffa

I would have the computer scanned for trouble codes first.
You can do an internet search for the procedure or have an import shop take a look at it. The diagnostic box is in the engine compartment.

I had the same problem and fixed it with only one nut to remove and one easy plug in part the Crankshaft Position Sensor is located between the firewall and the engine on the bell housing which connects the engine to the driveshaft Right on the top shine a light down in there and remove the nut to the left of the sensor sticking up and unplug it check the wires to see if they are rotted mine were all rotted and touching eachother went and bought the part at autozone for $55 plugged it in and it now works perfectly! hope this helps

These things are repairable by a DIYer for sure.In order to do that and have a reasonably reliable car you should invest in some manuals. Locate a Haynes manual for starters, it will give you the proper way to make a lot of common repairs (like the ones you want to do) as well as some tips and warnings. They usually cost about $20. Ideally it would be best to find a dealer service manual because it will have a lot of diagrams and info that may be needed at a later date or for a different problem ( like computer codes, wiring diagrams). They usually cost a little more but they could save your car from the crusher before its time. You will also have to invest in a good trolley jack and some jack stands. ALWAYS use the jack stands when the car is off the ground.
Pricewise, doing your own repairs can save a lot of money over taking it to a shop because you aren't paying labour but it also eats into your free time. For sure fixing your own car will be cheaper than making car payments on a yearly basis as long as you realize that at some point it is time to quit. Shopping at a local auto parts store rather than the dealer can help as well, especially if you patronize one specific one. This could save you in the long run. I do this and recently had to buy a new heater switch for my VW, list price was over $300. As a regular customer I ended up getting it for $180, basically cost. Shop around until you find a store you are comfortable with and then stop.
Hope this helps.

I wouldn't drive it... when your brake light comes on, it means there's a serious fault with your brakes. They may not engage when you brake and there won't be any further warning other than the brake light

My car just had the same problem and i bought a over-drive bypass plate from IPD and now it works just fine, just put it on yesterday. My overdrive solenoid was the problem. So, instead of paying $160 for a new one, i paid $40 for the bypass plate. I drive a 91 Volvo 940 Turbo with over 250K miles and now i have my overdrive back. I think if your overdrive relay was bad, the shift light would come on on the dashboard. So it may just be your solenoid. Go to http://www.ipdusa.com/Volvo-940960/Transmission-&-Drive-Train/Automatic-Transmission/Automatic-Over-Drive-Solenoid-Bypass-Kit/p-136-278-676-1031/

IPDusa.com.  If its similar to a 240 (and it most likely is) you can purchase a block off plate for the solenoid so you won't lose 4th gear (actually its OD from torque converter lockup).
http://www.ipdusa.com/Volvo-940960/Transmission-&-Drive-Train/Automatic-Transmission/Automatic-Over-Drive-Solenoid-Bypass-Kit/p-136-278-676-1031/

1st thing, check the relays, behind the ashtray, give 'em a gentle twist, while turning the engine.
Bon chance.

Sounds like you need an O2 sensor. You need to have it scanned, places like AutoZone will do this free of charge.

crank sensor problem