Hard Start

DEFINITION: Engine cranks fine but does not start immediately. Does eventually run, or may start but stalls immediately.

Check normal Scan tool readings of:
^ Engine Coolant Temperature (ECT) sensor
^ Manifold Absolute Pressure (MAP) sensor
^ Throttle Position (TP) sensor
^ Intake Air Temperature (IAT) sensor

Check:
^ Fuel system and fuel quality
^ Idle Air Control (IAC) valve carboned up
^ Arching spark plug boots
^ Engine mechanical problems (e.g., low compression, sticking lifters, worn valve train)
^ Carbon deposits in intake manifold
^ Worn spark plugs