Hard To Start, Long Crank, Erratic Crank Or Erratic Start

Check for erratic signal to ignition coil.
Check for vacuum leakage.
Check for poor fuel quality.
Check for starting system malfunction.
Check for spark plug malfunction.
Check for fuel pressure regulator malfunction.
Check for air leakage from intake-air system.
Check for erratic signal from CKP sensor.
Check for erratic signal from CMP sensor.
Check for improper air/fuel mixture ratio control.
Check for air cleaner restriction.
Check for improper operation of electronic throttle control system.
Check for PCV valve malfunction.
Check for operation of immobilizer system.
Check for PCV valve malfunction.
Check for inadequate fuel pressure.
Check for purge solenoid valve malfunction.
Check for MAF sensor contamination.
Check for restricted exhaust system.
Check for EGR valve malfunction.
Check for restricted or plugged fuel lines.
Check for pressure regulator malfunction.