It came home yesterday, and this morning it refused to start. Even though I can hear the fuel pump engage, I tried a shot of starting fluid into a vacuum port on the intake. It made no difference. I pulled all six plugs and did a compression test. All were between 120 and 130 PSI except one that showed 150. That shouldn't keep it from starting. So I laid all the plugs atop the intake with their wires connected and checked for spark. None of them sparked. The check engine light is not on. What is the most likely cause for this situation?