2008 S60, 2.5 turbo. Hard start condition. Over the past few weeks it's had starting issues, mostly when cold. Cranks over fine, battery is good. Only code was P0336 - crank sensor. Replace the sensor and cleared the code. No improvement. Checked spark plugs - very wide gap with significant erosion of electrode tip. Replaced all five. Air filter is fine. Finally got it started simply by trying it from time to time during the day. Drove it for awhile. No new codes. Problem remains. Checked plug to crank sensor. Someone before me apparently stripped a tiny bit of insulation from ea sensor lead, I suppose to check voltage. They were not taped well so I thought maybe there's voltage bleed from one or both. Replaced sensor wire harness plug. Made sure to twist the leads as factory leads were, I suppose to cancel any stray interference. Engine started but in all instances of it starting over the past few weeks of this, I think the engine is cranking over just a bit more than normal, that is prior to this problem manifesting. Since clearing the first code no new codes have set. Live data test of fuel system pressure, check via scan tool shows consistent pressure around 43.x. Engine will not start this morning. Thoughts? What do I check next?