What Causes Unstable Engine Speed in Cars?

[DeElla]

Here are the specific reasons for unstable engine speed in cars: 1. Intake manifold leakage: Air leaks in the intake manifold cause the air-fuel mixture to become too lean. 2. Low fuel pressure: Clogged fuel injectors or fuel filters result in insufficient fuel injection or delayed fuel delivery. 3. Faulty throttle position sensor signal: Abnormal signals from sensors like the mass airflow sensor, intake manifold absolute pressure sensor, or throttle position sensor lead to inadequate fuel injection. 4. Faulty sensor signals: Incorrect sensor signals cause improper ignition timing, resulting in delayed ignition. 5. Faulty high-tension wires: Weak spark issues caused by faulty spark plugs, ignition coils, or high-tension wires.