I have a 1986 nissan 720 with 2.4 fuel injected and it won't start. Good resistance in ignition coils, new plugs, wires, rotor and cap. Good pressure in fuel tank and fuel filter. At first it started as a sputter and within a mile barely running. That's when I replaced everything and tested the coils. Now it won't start. You can hear the fuel pump buzz and the fuel relay click. Starter turns over, but engine won't fire. Also checked EGR, diaphragm good. No cracks in vacuum lines. Does anyone know if it's fuel, spark, or air? Can someone point me in the right direction?