Its a six cylinder. Van wouldn't start so I checked for spark at the coil. So I replaced it and still no spark. Next I checked the ASD relay by swapping it with the starter relay with no success. The Van is getting plenty of fuel as seen by the saturated spark plugs. I'm wondering if the optical sensor under the dist cap could be causing this as for the rotor and cap look OK. Or is there something else I should check for?? I did observe 12v to the coil while cranking.