I was driving my '98 V70 awd (light pressure turbo-- 103 k miles). I punched the accelerator to try to pass someone, and the car lost power and died. I let it sit for a minute and started it up and it started OK, but when I put it in drive, it sputtered and died again. I was in the middle of nowhere in Canada: thought I was stuck. I unplugged a wire that attaches to a cylinder-shaped unit that is attached to the air filter box (and is right next to the fuse box). The car ran fine after that. I made it home, but I do not know what I unplugged or what to do to fix the original problem. Also, I am hoping I did not damage the car by running it with that unit (whatever it is) unplugged. Any hints/suggestions? Thanks

That does sound like you could be talking about the mass air sensor, and it sounds very reminiscent of the behvior of a bad AMM in an earlier RWD Volvo. It also sounds like my 98 S70 when I had a bad MAF, but it should throw a code. And that code should be one associated with MAFs if you search BB. Anyway, I popped in a used $25 MAF and off I went with nary another stumble.

If the unit you unplugged is about 3" in diameter and has a large hose going down to the turbo, it's the mass airflow sensor. Try cleaning the electriical conection and apply some dielectric grease. If that doesn't help, you'll need a new sensor.

I have no clues for you, but I am astonished that you disconnected a totally random wire and your engine started running fine. Did you try reconnecting it to see if the problem returns?

I'd love to be stuck in the middle of Canada, but perhaps when it is a bit warmer.

Yes, I reconnected it and the problem returned.

Beautiful in Canada (Quebec) at this time of year

I vaguely recall the MAF connector trick too.

It's amazing what a howling pack of Canadian wolves can make you remember. As above it's likely either the connector or the sensor.

-BTC

'98 V70 T5 5-speed, 174k mi, heated velour cloth comfy chairs, factory HD suspension, Bilstein HD, front IPD stabilizer bar, Volvo strut tower brace and skidplate, XC grill, C70 jewel E-Codes, V-1, Lidatek, IPD stuff, JB Weld, Original Duck tape, zip-ties, two '06 Honda license plate nut impressions in back bumper (gift from daughter), Mobil-1 since new.

"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." - Douglas Noel Adams (1952 - 2001)