S40: Slow stuttery acceleration, lose of power, rough idle

[InkdOutLife]

2000 S40. 180,000 miles. For some time now the vehicle took a few seconds to start. Started better in cold weather. Some times right away. Coming back from out of town yesterday vehicle became very rough like. Meaning while idling it acts like it wants to cut out then catches its self. But does it over and over again. But only some of the times. Others it works and sounds fine. Or it might be as subtle as like a hickup in the idle every 10 sec or so. Has not stalled at all though. While driving there is now a rough stuttery puttering slow feel to acceleration worsened if i apply more pressure to gas pedal. Acts as if has no power. Then at times its fine. More Not though. PLEASE HELP i learn fast and am mechanically inclined, What can i do to fix. Thank you

[dieselderv]

Sounds like the coil pack/packs to me
I had a v40 a couple of years back and 2 of mine were cracked

[Alexjansen]

Could be the EGR That is nearly blocked, try and disconnect it

[JonnyBigWheels]

I had a similar thing on my MK1 S40 1.6, try this, with the car running remove the plug from the MAF sensor (the part between the throttle body and the air box that has a loom going to it) then see if the car stays the same, it should stutter and die so if it doesn't it's either faulty or needs a clean so try cleaning it first, i got some electrical contact cleaner, took the MAF sensor off and cleaned the electrode with it, put it back together and hey presto, now it idles nicely and picks up as i feel it should for a 1.6.


See the meshed area, inside there is a tiny electrode poking out, spray the electrode cleaner onto it for around 10 then let dry, do not use any carb cleaner products as they might wreck the sensor.
Plug the sensor back in and start her up see how she sounds, if you notice a difference in a possitive way then that might be your solution, if not then i am lost beyond there.
As a process of elimination i would try this.