Hi

I have a V40 1.8i Sport Lux 2002. I have just had the Throttle shutter housing replacing as the engine wouldn't rev over 2000 rpm and if it did it was very erratic. I was told the ETV was seized. This cost just under £700 from my local dealer.
As soon as I collected it I noticed a new problem:

When coasting along in traffic or down hill, clutch depressed and right foot covering the brake pedal, the revs jump from 800rpm to 2000 rpm and back again. It seems to happen every time I hit the brake pedal???

My dealer advised me on my initial visit that I didn't have Volvo spark plugs fitted and this was causing a misfire - They had only been fitted the week previous during a full service froma reputable garage so I asked them not to change them. The car doesn't appear to misfire at all.

Doesn't anyone have any advice or experience of the problem I mentioned or could it be related to the spark plug problem??

Thanks
Rob