Difficult To Start/No Start (Cranks Okay)

Check idle speed control servo (if applicable).
Check stepper motor (if applicable).
Check ignition switch.
Check camshaft position sensor.
Check crankshaft position sensor.
Check park/neutral position switch (A/T).
Check airflow sensor.
Check coolant temperature sensor.
Check power supply to ECM ground.
Check fuel pressure.
Check for disconnected or damaged vacuum hoses.
Check for control relay malfunction.
Check for MFI system malfunction.
Check for fuel pump drive control system malfunction.
Check for ignition coil malfunction.
Check for ignition timing malfunction.
Check for power transistor malfunction.
Check for fuel injector malfunction.
Check for ECM malfunction.
Ensure electrical harness, connectors and wires are not broken or loose.