* Major Issues (most likely):
* Fuel System Problems: This is a prime suspect. Issues like a clogged fuel filter, a failing fuel pump (unable to supply enough fuel), a malfunctioning fuel pressure regulator, or even a blocked fuel injector can cause the engine to starve for fuel, leading to stalling and erratic idling.
* Ignition System Problems: A failing ignition coil, worn spark plugs, damaged spark plug wires, or a malfunctioning distributor (in older vehicles) can prevent proper ignition, causing misfires and stalling.
* Engine Mechanical Problems: This is a broad category, but crucial to consider:
* Low Compression: Worn piston rings or valve problems can lead to insufficient compression, preventing the engine from generating enough power to keep running.
* Vacuum Leaks: Leaks in the intake manifold or vacuum lines can disrupt the air-fuel mixture, causing unstable idling and stalling.
* Crankshaft Position Sensor (CKP) or Cam Position Sensor (CMP) Failure: These sensors tell the engine's computer the crankshaft and camshaft position, vital for proper timing. Failure causes misfires and stalling.
* Mass Airflow Sensor (MAF) Problems: A faulty MAF sensor provides inaccurate air readings to the engine computer, leading to a poor air/fuel mixture.
* Less Likely (but possible):
* Alternator Issues: While less directly related to stalling, a failing alternator can cause the battery to discharge, eventually leading to the engine dying. You might notice other electrical problems as well.
* Battery Problems: A weak or dying battery can't provide enough power, leading to stalling.
* Transmission Problems (Automatic): In automatic transmissions, a problem could cause the engine to stall, but RPM dropping to zero often points to engine, not transmission, issues.
* Throttle Body Issues: A dirty or faulty throttle body can affect the air intake and cause idling issues.
What to do:
* Do NOT continue driving. This is a serious issue that could leave you stranded or cause an accident.
* Have the vehicle towed to a qualified mechanic. Describing the symptoms accurately will help them diagnose the problem more efficiently.
* Avoid attempting DIY repairs unless you have significant mechanical experience. Incorrect repairs can worsen the problem and potentially cause further damage.
The RPM dropping to zero strongly suggests a fundamental issue with the engine's ability to function. Professional diagnosis is essential to identify the root cause and prevent further damage.
