Engine Starts Then Dies When Cold
The engine starts but stalls shortly after, especially when cold. This often indicates a fuel delivery, air intake, or sensor issue that prevents the engine from maintaining idle after startup.
Diagnosis Details
Possible Causes
Faulty engine coolant temperature sensor (ECT) sending incorrect signal to ECU, causing overly lean or rich mixture
Dirty or failing idle air control valve (IACV) or throttle body, restricting airflow at idle
Weak fuel pump or clogged fuel filter, not maintaining pressure after initial start
Vacuum leak (e.g., cracked intake hose, gasket) causing unmetered air entry
Faulty mass airflow sensor (MAF) or intake air temperature sensor
Related OBD-II Codes
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What You Should Do
Check for diagnostic trouble codes (DTCs) using an OBD-II scanner.
Inspect the engine coolant temperature sensor and its wiring.
Clean the throttle body and idle air control valve.
Test fuel pressure and check for vacuum leaks.
If no codes, monitor live data for ECT, MAF, and fuel trims.
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Disclaimer: This AI-generated diagnosis is for informational reference only. Always consult a qualified mechanic for an in-person inspection. AutOwner is not responsible for decisions made based on this information.
