What Causes Car Shaking During Startup?

[Renee]

The reasons for car shaking during startup are: 1. The throttle is dirty or the fuel injector has excessive carbon deposits. The gasoline sprayed by the cold-start injector is largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts, making it difficult to start; 2. Irregular wear of the clutch three-piece set (flywheel, clutch disc, pressure plate), causing one or several components to become misaligned; 3. Aging of engine components; 4. Abnormal fuel pump pressure or incorrect readings and poor performance of the intake pressure sensor; 5. Increased spark plug gap, leading to reduced ignition energy; 6. Improper air-fuel mixture ratio.