My XC70 wagon won't start. The engine turns and turns, so no problem with the battery or starter. I replaced the sparkplugs yesterday, they had 120,000 miles on them. Still didn't start. Should I now replace some or all of the ignitional coils. That's an expensive proposition. Is there a way to check if they are good or not? When I went to install them, 2 or 3 seemed like they did not snap into place around the sparkplug end. Could that bad connection be it? Appreciate your help.