David,
More info would help to point you in the right direction.
Basically you need Ignition, Compression and Fuel
Compression- Is engine turning over or cranking (battery, connections, starter, relay)
Fuel- Are you getting gas to cylinders (fuel, fuel pump,injectors and sensors)
Ignition- Spark to to cylinders (spark plugs, ignition coil, plug wires and sensors)
Hope this gives you a direction, Glenn