Will start but stops running after 20 seconds

The Mass Airflow Sensor measures air entering the engine and relays this to the car’s computer so it can meter the amount of fuel delivered from the injectors. When the sensor fails, fuel delivery is impaired and often the engine dies soon after starting. A defective Idle Air control Valve produces the same result during start-up. The Fuel Pump Relay works similarly and when defective, it can't control the pump properly during the start-up process, so the engine will die immediately after it starts. Other defects that could cause an engine to die right after it starts are, a failing crankshaft or camshaft position sensor, a severe vacuum leak, a faulty ECM, or anything that impedes proper spark. Timing can also be an issue with a worn belt. It's best to have OBD codes read and follow what shows up, or you could be searching for a long time.

WELL, HERE WE GO AGAIN - NOT POSTING ----- The Mass Airflow Sensor measures air entering the engine and relays this to the car’s computer so it can meter the amount of fuel delivered from the injectors. When the sensor fails, fuel delivery is impaired and often the engine dies soon after starting. A defective Idle Air control Valve produces the same result during start-up. The Fuel Pump Relay works similarly and when defective, it can't control the pump properly during the start-up process, so the engine will die immediately after it starts. Other defects that could cause an engine to die right after it starts are, a failing crankshaft or camshaft position sensor, a severe vacuum leak, a faulty ECM, or anything that impedes proper spark. Timing can also be an issue with a worn belt. It's best to have OBD codes read and follow what shows up, or you could be searching for a long time.