Engine Cranks But Won't Start (Cold Start Issue)
The engine cranks but fails to start when cold, indicating a fuel, ignition, or sensor problem. Common causes include a faulty fuel pump, bad spark plugs, or a failing engine coolant temperature sensor.
Diagnosis Details
Possible Causes
Faulty fuel pump or fuel pressure regulator - insufficient fuel pressure when cold
Bad engine coolant temperature sensor (ECT) - incorrect cold start mixture
Worn or fouled spark plugs - weak spark in cold conditions
Crankshaft position sensor failure - no spark or injector pulse
Clogged fuel injectors or fuel filter - restricted fuel delivery
Related OBD-II Codes
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What You Should Do
Check for fuel pressure at the rail (should be 44-50 psi).
Inspect spark plugs for wear/fouling.
Test the engine coolant temperature sensor resistance with a multimeter (compare to specs).
Scan for diagnostic trouble codes.
If no codes, perform a no-start diagnostic: check for spark, fuel, and compression.
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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.
