Engine Starts Then Dies - Ford Mustang 2020
The engine cranks and starts but immediately stalls, indicating a fuel, air, or spark delivery issue after initial ignition. This is often caused by a failing fuel pump, faulty engine control module (ECM) relay, or a security system immobilizer problem.
Diagnosis Details
Possible Causes
Fuel pump failure or weak fuel pressure – the pump may provide enough fuel to start but not maintain pressure.
Faulty engine control module (ECM) relay or fuel pump relay – intermittent power loss after start.
Security system immobilizer issue (e.g., PATS system) – prevents engine from running after start.
Vacuum leak or mass airflow (MAF) sensor malfunction – causes incorrect air-fuel mixture after start.
Related OBD-II Codes
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What You Should Do
Check fuel pressure at the rail; if low, test fuel pump and relay.
Scan for immobilizer or ECM-related trouble codes.
Inspect MAF sensor and intake for leaks.
If no codes, verify security system operation.
Related Repairs
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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.
