Why does the Chery A3 have unstable idle speed with fluctuations?
3 Answers
Chery A3's unstable idle speed is mainly caused by low ignition energy, malfunctioning water temperature sensor, and improper air-fuel mixture ratio. Low ignition energy: When the engine temperature is insufficient, fuel atomization is poor. After prolonged use, the spark plug gap increases, leading to decreased ignition energy which affects power performance and causes unstable idle. Malfunctioning water temperature sensor: A faulty water temperature sensor cannot accurately determine engine conditions, resulting in reduced fuel delivery and unstable car idle. Improper air-fuel mixture ratio: If the air-fuel mixture ratio in the car's engine compartment is improperly adjusted, the vehicle becomes prone to shaking.
I've been driving a Chery A3 for five years, and the unstable idle speed is really a headache. The most common issue is a dirty throttle body, where carbon buildup in the intake port causes fluctuating air intake, making the RPM surge up and down. The fuel injector is another troublemaker—unstable fuel pressure or gum deposits can disrupt the fuel injection. If the spark plug gap is too wide, the ignition becomes uneven, and the tachometer dances. From my experience, don’t overlook those rubber hoses; aging can cause air leaks and disrupt vacuum pressure. If the engine mounts are loose, the engine will shake more noticeably. My advice is to regularly clean the throttle body, inspect the ignition coil wiring, and change the engine oil on schedule as per the manual. For a real solution, it’s best to visit a professional shop and use an OBD scanner to check for trouble codes.
During car repairs, I've encountered numerous idle issues with the Chery A3, primarily stemming from three systems: fuel, ignition, and electrical. Insufficient fuel pump pressure disrupts the injection timing, while oil-contaminated mass air flow sensors send erroneous data, causing the ECU to misfire fuel injection and ignition commands. Aging ignition coils with current leakage can suddenly disable a cylinder, leading to engine vibration. A faulty crankshaft position sensor makes the ECU lose accurate ignition timing. Clogged fuel filters also cause poor fuel delivery. For a thorough fix, prioritize replacing aged vacuum hoses, cleaning intake manifold carbon deposits, and using double-iridium spark plugs for extended lifespan.
