I have a s80 2002 , drives smooth , but misfires , I went over a pot hole it was at night , then 300ft roughly down road engine light flash then stops then starts again. Carefully drove way home . So I got new spark plugs . Old ones were bad figured that would help . It didn't . Cylinder 2 misfires but piston is moving , coil is sparking , I believe it's something to do with vacuum pump. Cause the fuse is blown for it . I checked the lines they all appeared to be fine , the hotter it gets outside it appears to fire up a little bit longer then normal then goes back to misfiring.

 

did you try swapping coil packs between #2 and another cylinder? Coils can fail but still produce a colder spark. ALso check the connectors to the coils to look for cracks in the wires going to the coils. When I replaced the coils on my 00 S40 I also did the wire harness and good as new.

 

Yea I did that , didn't make a difference even swapped spark plugs to see if I had a bad one.
I will have to check connectors to see if cracked .

It's sparking , just not sure why it's not firing up