One system tune up. Customer says zones are not keeping up. Tested system. Zone dampers are functioning properly. Found evaporator coil slightly dirty. Found air leakage where unit connects to supply plenum. Added tape to better seal airflow. Recommend sealing with mastic. Found weak capacitor and system is overcharged. Recommend replacement of capacitor and adjusting refrigerant pressures. Recommend cleaning of evaporator coil. Return ductwork is undersized by 300 cfm, recommend installing another 10†return for proper airflow. Supply ductwork is undersized by 120 cfm, recommend installing another 8†duct with damper for improved airflow. System is cooling at this time.