Bought this car 2 months ago and this has happened twice now: I'll be driving along and notice that the car seems not to be able to decide which gear to be in, especially when accelerating/decelerating, and jumps around between gears. Then, the next morning I go to start it and it runs really rough, the check engine light comes on and the codes are misfires on all the cylinders. By the way, does anyone know what code 1310 is? The guy at Autozone couldn't identify it, and my volvo guy says it's not a volvo code. Anyhow, the car will run smoother as the day goes on, then the next day it will be rough again, but not as rough, and by the end of the day it's idling smoothly. The next day, the problem is gone and it idles as good as new for a few weeks. My indy Volvo guy (Robert's Volvolab in No. Reading MA) says it's too hard to tell what it might be if the car's running well when I bring it in. Any ideas what this might be?

Also, Robert up at the Lab suggests using mid-grade gas from Texaco or Shell only, and says Mobil sucks. Thoughts about that?

Could be a coil. I had the same symptoms on a 760 Turbo, and the only way the mech found it was to leave it at his door and let him test it. It would do this after any reasonably long trip and driven faster than I do in town. When it cooled down after the trip (next day) it would be as rough as it could be. He found it in 4 hours and only charged me forthe coil.

I would agree about the coil, I had the same problem when I purchased my 95 854T with 80k. Replacing the coil helped for the most part, but in my case the idle was still irregular until I cleaned the throttle body/fuel system and replaced the fuel filter. Misfire on all cylinders almost has to be a coil problem I would think (same code I was pulling).

Brandon
95 854T 90k
95 944 114k

Thank you both. What a great resource this is! I'll check it out.