Magnacores work well on my car. I found holding the wire behind the copper connector with needle nose pliers and rolling the rubber boot back on itself exposes the connector enough to make sure it seats correctly. Then roll the rubber back down over the coil. Do not use any grease. Also the plastic clips on the coil pack primary side break you could check that. Also, check for corrosion on the metal backing of the coils that touches the valve covers. Good luck.