Q: Ford Fiesta TDCi starts and stall immediately

If the engine overheated, there is the possibility of engine damage (stuck valves, etc.) so it might be necessary to test for basic cylinder compression. If the engine is mechanically sound, what you are describing is diagnosed in a stalling diagnostic. Typical causes of such immediate stalling are a faulty mass airflow sensor, faulty engine coolant temperature switch/sensor (typically at cold start only), faulty camshaft or crankshaft position sensors, worn spark plugs, wires or defective ignition coil(s), inadequate fuel delivery or pressure (clogged fuel filter, injectors, faulty fuel pump or pump circuit), contaminated or old gasoline, defective throttle position sensor, faulty idle air control valve, leaks in the EGR system, intake vacuum leaks, and so forth. If you request an engine stalling diagnostic the responding certified mechanic will get this resolved for you promptly. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.