My girlfriends 99 V70 has been having an odd idle fluxtuation where after starting or while sitting at a stoplight the RPM's at idle pulse between 300 and about 1000. It's quite noticeable, and seemed to come and go intermittently and she largely ignored it.

Yesterday we stared the car up after doing some shopping and all of a sudden the same fluxtuation seem to be magnified ten fold! The RPM's were pulsing-but now between 200 and 2000!! Very aggressive to the point of the dip would seem to almost stall the engine and the upswing would torque things up. This happens every 1 to 2 seconds and is very consistent.

I put it in drive and it drove ok (when I accelerated, RPM's going over 2000 or so, it seemed to drive ok). As soon as I backed off the gas (say, once up to 25 or 30mph and cruising on the street) I would then again notice this aggressive engine revving. It never went away or eased back.

We managed to limp home about 7 miles. Twice the car stalled at stop signs. I would put it in neutral a glide often because the revving seemed to really torque on the transmission- especially bad at slow car speeds.

What in the name of Sweden could be causing this? My first guess would be something in the engine management system- electronics? Computer? Idle control of some sort?

Help!
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89 245 'loaded' with a Great Pyrenees; 91 245 project

If the throttle (ETM) is original to the car, you should have a check engine light or warning messages. I suggest www.xemodex.com for complete repair.

IF you have no CEL or other warnings, look for a broken vacuum line.
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My back feels better when I sit in a Volvo seat

Volvo won't help you on this. The car is over 10 years old at this point. I had ETM problems with my 2000 Volvo V70 XC Wagon last year and all the Volvo Dealership did was reload the software for it and do a cleaning on it. Three days later it bit the dirt!

IF you are having serious issues with it, then look at BBA Reman out of MA. $400 for a replacement with a lifetime warranty on it.

or

you could try Amsoil PowerFoam product which will clean up the gummed up ETM Module while it is on the vehicle. To get your hands on this product go to www.weareoil.com for more info.

Hello, It sounds like your electronic throttle body is giving up the ghost. That would be lucky for you as the warranty for said part has been extended by Volvo to 10 years/ 200,000 miles. Pray it's your throttle body AND you have fewer than 200K on the odometer AND the car wasn't put into service before September 29th, 1998. Let us know what happens. Kira