1977 Porsche 924 Spark, gas, timing, but won't start

I just recently replaced the head gasket on my car. Before I did so the car woulds start only with excessive cranking but it ran ok. After I replaced the damaged head gasket I timed the car, tested the spark(good) and have seen the injectors work. Why won't my car start? It doesn't even sputter. I also have a new cap and rotor, coil, fuel filter, good battery. Please help me.