I have a 2001 s40 with 55,000 one day it was functioning fine next day no acceleration, mechanic said the turbo is no good, also the hoses have rust and need changing, I live in guatemala and hard to find information,
scanned the codes everything is fine, starts, idles, runs fine, no acceleration, came home one night every thing was fine, next morning go out, no acceleration, no misfires, havent checked the fuel pressure
Hook up a fuel pressure guage and let the car sit overnight (run the car for a few minutes with the guage on before letting it sit). Then in the morning watch it when you try to start the car. If the pressure was real low and takes a few seconds to come back up to pressure it will most likely need a fuel pump or possible pressure regulator. I can't really tell you what to find for sure because every problem like this is very different. To find it, you will have to have some technical abilities and access to diagnostic tools, like a fuel pressure guage to be sure of what you find, otherwise everything is just going to be an educated guess.