Hi all!
I've been experiencing this problem for some time and don't quite know how to proceed.

When the car has warmed up and I begin to accelerate from a stop, there is dramatic and rapidly intermittent hesitation, almost as if I were pumping the brakes with my other foot. This also happens at 40+ mph. It seems to be getting worse. I have removed and cleaned both MAF sensor and the ETM, but neither seem to have had an effect. I was told that I should check the PVC system too, but haven't had the time to figure it out yet. Other ideas have ranged from catalytic converter to brakes themselves.
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1982 245, 2001 v70 XC

Wow, that can surely be caused by all sorts of things. Probably not the cat.

Have you read the codes, looking for any 'pending' errors? Is the ETM white or yellow label, white are no good. Is the ABS/trks light on?

It could also be the AWD system if the tires in the rear are worn more than the front. That can cause the ABS to activate eventhough there is no slippage.

You have individual coil overs, so inspect them and the sparkplugs.

A broken or loose vacuum line could cause rich burning, which can foul the plugs during accelleration.

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My name is Klaus and I am a V♂lv♂holic

Klaus, thanks for the reply. I tried to do the email reply thing, but it was bounced back.

In any event, I haven't read the codes myself, but when I took it in to a local import repair place, they said they didn't get any codes--they did change the timing belt though. Can I just buy an OBDii reader and look for codes myself? If so, is there one you'd recommend?

ETM has the white label. Incidentally, it's an '01, so it's not eligible for the recall, I think. Has this become an essentially necessary replacement? If so, is the Xemodex route the best way to go?

ABS light is not on and all four tires are pretty new (though, I'll double check wear when Wifey returns home).

I've never inspected coil overs, but I suppose I could see if there is any obvious damage. As for the spark plugs, I'll pull and inspect those too.

For some reason, I've lived under the impression that vacuum leaks are hard to trace, and have thusly been a little daunted by them, but I'll definitely look around and see if any hoses are loose or dangling.

Thanks again!

pete

PS Car has c. 75K original miles.
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1982 245, 2001 v70 XC

I hope this happened before the Tbelt and tensioner were replaced.

Most autoparts stores, not sure about AK, will loan you a scanner for parking lot use. I suggest plugging it in and driving in the lot to duplicate your problem. If there are no errors, then the engine 'should' be OK.

Is it possible that the front CV on the prop shaft has come loose or failed? The bucking could be from that, the additional power putting stress on the CV. You should feel that by holding on to the shift knob and noting vibration.

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My name is Klaus and I am a V♂lv♂holic

Klaus,
I thought, I'd follow up and report, that I found a good independent mechanic (former head at dealer shop) who confirmed that my problem is indeed the ETM. Unfortunately, I didn't know this was a common issue when I bought the car (a month or so before my 10 year replacement window closed!!).

My only remaining question has to do with the provenance of the ETM that is in the car. My mechanic suggested that it's possible that the ETM may not be the original one to match my VIN (i.e. that the ETM, may be fine, but that the car doesn't 'recognize' it correctly. Do you know, by chance, how one would determine this definitively? I have all the numbers off the side of the ETM and the guy at the dealer parts counter would only tell me that the model number is correct for my car's vintage. I guess, I'm asking whether my ETM would work after getting the Xemodex repair. Of course, you may have no clue, but I thought you might know better that others. Thanks for your time!
pete
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1982 245, 2001 v70 XC

I suspect that yours is original to the car. Updated ETMs have a yellow tag and last a bit longer.

Xemodex will ensure that the codes are correct if you send them the original ETM. No dealer software is needed.

Of course, if you take your car to the dealer, they will 'clean' it and run a program so that the ETM uses new areas of the plastic sensor. That usually works for about 10-20K miles.
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My name is Klaus and I am a V♂lv♂holic

Indeed, Klaus, these symptoms were present prior to the timing belt replacement.

I'll check with the local parts place, re. scanner.

Buy 'prop shaft', are you talking about the 'drive shaft'? In any event, no vibration in the shifter.

It's too late this evening to pull the plugs, etc., but hopefully in the morning...

I could be totally off base, as I don't even approximate a trained mechanic, but it doesn't feel mechanical in the sense that something rotating is out of whack, but more like a spark or fuel system issue. Then again, I've accidentally misled people before, so I'm willing to pursue all leads. Spark, though, is on my to-do list tomorrow.

FYI and in order not to leave anything out, I'll say that this car was in an accident prior to my purchase. It was a front end accident that deployed the dash and driver airbags, but nothing else. These haven't been replaced. I did get a pre-buy inspection (at Arctic Import, for those in Anchorage) and they told me every thing was honky-dory, but I'm not sure how thorough they were.

Finally, I've browsed these forums enough to know what an important resource you are to this community. I know you've heard it before, but thank you for sharing your vast knowledge and patient tone with the rest of us.
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1982 245, 2001 v70 XC