Difficult Or No Start (Cranks Okay)

Check for dirty or clogged fuel filter.
Check for lack of fuel in tank.
Check fuel pressure and volume.
Check for contaminated fuel.
Check for vacuum leaks.
Check for low compression.
Check for blown ignition fuse.
Check ignition and valve timing.
Check spark plugs.
Check for adequate spark with a spark tester.
Check for faulty ignitor/coil assembly.
Check for faulty Engine Coolant Temperature (ECT) sensor.
Check for faulty Mass Airflow (MAF) sensor.
Check for faulty Idle Air Control (IAC) valve.
Check for faulty power unit.
Check for faulty Camshaft Position (CMP) or Crankshaft Position (CKP) sensor.
Check for malfunctioning PCM.
Check for malfunctioning electronic fuel injection system.
Check for slipped or broken timing belt.