Hey guys, m y 99 S70 2.5 N/A has just recently started acting up. ROUGH startup and stuttering until warmed up. Here's what I found though, If I pull a coilpack connector off a cylinder, the rpms drop off as they should, all except for cyl #4. So I swap in a known good coil pack onto the #4 cylinder, and still no fire.

What triggers the firing on these distributorless ignitions?? As it seems there is no spark be sent to that cylinder??

 

Could be a bad spark plug.

 

Our S70 was missing. I pulled the plugs, cleaned them off, re-gapped them, and the problem went away. I immediately order a full tune up kit from ipd.

 

what's the preferred plug for this car??? N/a