What Causes Car Engine Shaking During Ignition?
2 Answers
The reasons for car engine shaking during ignition are: 1. Dirty throttle body or excessive carbon deposits in fuel injectors; 2. Worn or loose engine mounts; 3. Engine misfire (cylinder malfunction); 4. Intake system failure; 5. Poor fuel injector atomization or clogging; 6. Additional air valve not opening or insufficient opening during cold starts. The correct steps for starting a car are: 1. Insert the key into the lock position without turning immediately, wait about 2 seconds; 2. Ensure the car gear is in P (Park) or N (Neutral) position; 3. Turn the key past ACC position and pause at ON position for about 5 seconds; 4. Turn the key to START position to ignite; 5. Release the key after engine starts (it will automatically return to ON position); 6. Press the brake pedal and shift gear to D (Drive) position; 7. Release parking brake and then foot brake.
I've been driving for over a decade and engine shaking during startup is common. I used to drive an old Toyota that would shake like falling apart during cold starts, making sputtering sounds. Later found out it was due to worn spark plugs causing unstable ignition, or low fuel pump pressure leading to insufficient fuel supply. There was also significant carbon buildup in the engine, especially for cars frequently driven short distances where fuel doesn't completely burn. Another time it was a faulty ignition coil causing uneven spark distribution to cylinders. Don't force it - get it checked early. Cleaning carbon deposits or replacing parts can restore smooth operation. Delaying might lead to stalling midway, which is both troublesome and dangerous. Regular use of fuel additives to prevent carbon buildup helps a lot - don't skimp on this small expense.