Spark Plugs,Spark Plugs spark once

My car suddenly didn't start. It’s been working great and now it won’t start. I've checked the injectors, fuel relay, fuel pump OVP relay, and they are good. The spark plug wires, distributor are new, and I checked the coil and EZL and CPS and they are all good on ohms. The thing that is puzzling is that my spark plugs only spark once. They have a nice bright blue spark, but the cylinders spark only once. One other thing I noticed was that my rpm needle goes up and down between 500 rpm – 1500 rpm when I crank the engine. This happens even though the engine spins at the sa