Hard Start

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

Check normal Scan tool reading of:
^ Engine coolant temperature (ECT) sensor.
^ Mass air flow (MAF) sensor.
^ Throttle Position (TP) sensor.
^ Intake Air Temperature (IAT) sensor.

Check:
^ Fuel system and fuel quality.
^ Engine mechanical problems (e.g., low compression, sticking lifters, worn valve train).
^ Carbon deposits.