The airflow sensor is essential for closed-loop electronic control, i.e. the EHA and the idle control valve. If you have it disconnected, then the computer has no way of knowing that input info, and it is reasonable it will produce no output. Since a start condition will not produce reliable inputs, some default parameters are necessary for this condition. The controls would be expected to look for closed-loop feedback as soon as the engine is running. If your airflow pot is bad, replace it before attempting further closed-loop diagnostics.