Engine Difficult To Start Under Cold Conditions

Ensure fuel system performs properly (fuel pump, fuel filter, fuel injector and fuel pressure regulator).
Check coolant temperature sensor and wiring.
Check STA signal at Engine Control Module (ECM).
Check idle air control valve (if equipped) and wiring.
Check cold start injector system (if equipped).
Check air temperature sensor and wiring.
Check Engine Control Module (ECM) and wiring.