My 96 Volvo 850 sometimes stalls while sitting at red light like its out gas sometimes starts back sometimes have wait a minute then goes for days before does it again

SOURCE: engine stalls

Sounds like a crank or cam sensor, very common with the 5cyl

SOURCE: have a 2002 saab 9-3

have a mechanic check evap purge solenoid, has been known to cause this condition.

SOURCE: 1997 volvo 850 abs light and trac light on

you will have to have the car diagnosed with a code reader most garages have them prices from £20-90 to diagnose the fault + parts.

SOURCE: volvo 850 won't start occasionally

Hey Kolby!

Sounds like you've got an issue with your alarm module, causing the immobilizer to activate (also known as a "start inhibitor"). I'm not sure what type of alarm you've got, but this will probably help you find out if there is something wrong with it:

There is a panel with relays on it behind the dash. At the bottom of the steering column, by the drivers feet, there is a panel. Remove it to get access to the relay panel (just a couple of torx screws, no breakable clips as far as I can remember). Remove the "double size" relay (probably marked 210-211). Put a wire between the terminals 50E and 50F. This will hotwire the immobilizer and make sure that it always activates when turning the key.

Drive around with the wire in place instead of the relay for a while to see if this helps. If it does you'll know that the problem is related to the alarm system. Keep in mind that you will be without alarm and therefore probably also without remote central locking while doing this.
Make sure that the wire is connected firmly enough so it doesn't come loose. You can also put a fuse on it if it makes you sleep better at night ;)

Good luck!

SOURCE: My 95 VOlvo 850 Tubo keeps stalling on me!

It's the solinoid. It's placed alongside the distributor. A coil about 1" around, and 2" long loosen, disconect the cable and lead coming out of it, repalce, and it will run fine then.