I had a similar symptom with my 855T. Turned out to be the rubber air hose between the IAC (idle air control) motor and the intake manifold had a huge hole in it. Oil soaked and rotted away. Not easy to see but easy to feel. Don't know if this will work, but here's link to the pic. IAC and it's lower split hose.



Another slow=running problem was caused by the plastic vacuum tree that lives under the throttle bellcrank cover. The cover had worn a dime-sized hole in back of the tree, allowing a lot of un-metered air into the intake.

I don't know if any of this applies to your V70 but major air leaks can cause what you're experiencing as well as fuel delivery problems.

Replace your fuel filter lately? I did mine at way too late, at almost 180,000 miles, and the gas that poured out of it was as black as Coke. The fuel pump diaphram had dissolved.

Good luck,

Erwin