What Causes the Ford Focus to Shake When Starting Cold?
2 Answers
The reasons why the Ford Focus shakes when starting cold: 1. Aging ignition coil: The high-voltage wire of the spark plug aging or leaking can also lead to reduced ignition energy; 2. Inaccurate fuel-air mixture ratio adjustment: This occurs in both open-loop and closed-loop control. If the car's computer makes an incorrect judgment, its control over the fuel-air mixture and ignition timing through the actuators may have errors, thereby reducing the car's power output and causing shaking. The Ford Focus is a Class A family sedan, with dimensions of 4647mm in length, 1810mm in width, and 1468mm in height. The Focus is equipped with two engines, the 1.5L EcoBoost and the 1.5L TiVCT, and all models meet the National VI emission standards.
Shaking like a sieve when just started? I've seen this a lot. When the engine is cold, the temperature is low, the oil flow is poor, lubrication is inadequate, and internal resistance is high. The direct injection system in Focus is most prone to carbon buildup at the fuel injectors, causing the air-fuel mixture ratio to go haywire. Spark plug aging and ignition coil leakage are also quite common ignition issues, especially noticeable when the engine is cold and misfiring occurs. I remember the last time I helped a neighbor check his car, his Focus had the crankcase ventilation valve behind the intake pipe clogged with sludge, causing poor exhaust gas recirculation and idle dancing. If the coolant temperature sensor gives false readings, the ECU's fuel delivery will be off, leading to shaking. To really solve it, I suggest first reading the fault codes, cleaning the throttle body and fuel injectors. If that doesn't work, check if the engine mounts have collapsed. Older cars especially need to watch out for degraded engine mounts - once those go bad, all the engine vibrations get transmitted straight into the cabin.
