Poor Idling

Check throttle switch and connection.
Check coolant temperature sensor and connection.
Check idle (air) valve.
Check air temperature sensor and mass airflow meter.
Check coolant temperature sensor.
Ensure spark plugs are not fouled.
Check ignition and sensor wires for proper connection.
Check idle valve. Ensure airflow arrow points in correct direction.
Check distributor (if applicable).
Check ignition and coil circuit.
Check intake system.
Check engine speed sensor.
Check throttle switch and connector.