I have a 2004 Volvo v70 2.5t p2 model with over 217,000 miles, let me explain a problem I'm having, when I start the car, the engine cranks but the engine does any of theses: guessing about 5-6 ways it starts. (1) starts well runs smoothly, or (2) starts but delay with small ruff then smooths out, or (3) starts ruffer then smooths out, or (4) cranks but harder to start running, or (5) cranks light diesels low engine rpm then picks up rpm to normal rpm warm up speed, or (6) cranks but seriously diesels, I turn engine off wait then restart then any of the first five or six opinions happen, More info, replaced sparkplugs and coils no changes also replaced fuel pressure sensor still no changes.
those are old money pits now. Often the throttle assemblies do go bad, check that first though
Have you watched this video