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 excessive carbon build-up or deposits
^ Arching spark plug boots
^ Engine mechanical problems (e.g., low compression, sticking lifters, worn valve train)
^ Carbon deposits in intake manifold
^ Worn spark plugs