Engine Difficult to Start When Cold

SYMPTOM:
Difficult to start cold.

CHECK:
1. Coolant Temperature Sensor (6)
2. Electronic Air Control Valve (EACV) (14)
3. Idle Controls
Fuel Injector(s) (16)
4. Electronic Control Unit [1]

NOTE: Numbers in parentheses are the blink codes displayed on the back of the ECU.

[1] (BU): When the Check Engine warning light and the self-diagnosis indicator are on, the back-up system is in operation. Substitute a known good ECU. If the indication goes away, replace the original ECU.