- Faulty Fuel Injectors: Clogged or malfunctioning fuel injectors can cause the engine to run rich, resulting in a strong fuel smell and rough running.
- Fuel Pressure Problems: Low fuel pressure can cause the engine to run lean, leading to a rough idle and poor performance. A fuel pressure gauge can be used to check the pressure.
- Ignition Problems: Faulty spark plugs, spark plug wires, or ignition coil can lead to misfires and a rough running engine.
- Vacuum Leak: A vacuum leak can cause the engine to run lean, resulting in rough idling and poor performance. Check for any loose or disconnected vacuum hoses.
- Faulty Oxygen Sensor: A faulty oxygen sensor can provide incorrect data to the engine's computer, causing the engine to run rough.
- Insufficient air: A clogged air filter, restrictive air intake hose, or MAF (mass air flow) sensor issues can cause the engine to run rough, rich and produce excessive fuel smell.
- Incorrect ignition timing: Incorrect ignition timing can cause the engine to run rough and affect fuel efficiency.
- Low cylinder compression: It could indicate a problem with the piston rings, valves or cylinder head gasket, resulting in rough running engine and fuel smell due to incomplete combustion.
