Hi All:
I am writing to see if any of you have had a simiar experience and any success finding a fix. I wrote a few weeks ago commenting our 95 850T had developed a high speed subtle miss. The miss has been getting worse over the last few months. After replacing wires, plugs, rotor, fuel filter, checking the location of the cam sensor wire, and draining and replacing the ATF, the problem is still there. Tricky in that it is not a constant miss. Sometimes the car runs without a miss at all (giving false hope of having found the problem) and then it will stumble in bursts. You can feel the subtle miss while stationary at a light, or sometimes while accelerating, or often cruzing at highway speeds. I really can't tell if it is an auto tranny issue, or engine issue. Any thoughts on this one? Any test to determine whether tranny or engine? (this is the only auto tranny we have ever owned)
Thanks for any help
Pete

 

I have seen a bad mass flow sensor cause this issue 2 times.

 

Is there a way to test the Mass flow sensor?
Thanks

 

It would be hard it test even if you could find the specs since it is an intermitant fault.

 

On our VW, you can test the MAF by unplugging it and seeing if the problem fixes itself. Of course this also causes the check enging light to come on. Not sure if this course of action is possible with the 850, but you can always try it and see

 

mine had a similar problem and it end up being the crankshaft sensor... I went over to the junk yard before I spend 100 bux and picked one up. I car has been running like a champ for 3 weeks now.. BUt yes I did have the miss that would come and go.. I did a full tune up and nothing helped

 

This seems to apply only on '96 & '97 but worth an inspection:

http://volvospeed.com/Repair/maf_secure.php

Also, see if there are fault codes stored in the engine & tranny ECUs:

Tranny:
http://volvospeed.com/Repair/a1.html

Engine:
http://volvospeed.com/Repair/a2.html

Or, you can visit a local AutoZone and have them diagnose with their scanner. If you take this route, be sure to tell them that your car DOES have OBD-II connection; in front of shifter right under the coin holder.

Good luck,


JPN

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Great suggestions
At least I have more things to try...
I cleaned the MAF last night (saw another thread that talked about how the sensor gets dirty) unfortunatly no change.

I'll keep at it this weekend, and report back if I can find this mystery miss!
Thanks
pete