What Causes Sudden Shaking When Accelerating Hard?
2 Answers
The reasons for sudden shaking when accelerating hard: 1. Damaged spark plugs - excessive gap wear leads to insufficient sparking, incomplete combustion of air-fuel mixture, or cracked ceramic parts causing misfires; 2. Poor fuel quality resulting in inadequate fuel injector atomization and incomplete combustion; 3. Uneven tire tread wear including bulges, foreign objects or loose wheel bearings; 4. Engine mechanical issues causing uneven cylinder pressure; 5. Fuel system problems where injectors fail to seal properly or get clogged due to excessive carbon buildup.
Having driven a taxi for over a decade, my first instinct in this situation is to check the fuel pump. Last time my car jerked and struggled to accelerate when I stepped on the gas, and the repair shop found insufficient fuel pump pressure – it couldn't keep up with fuel demand during hard acceleration. Replacing the fuel pump fixed it. It could also be aging ignition coils; a mechanic once told me that cylinder misfires become especially noticeable during hard acceleration. Severely eroded spark plugs can cause this issue too. Also inspect the high-voltage wires for leakage – these are prone to problems in wet weather when aged. The most easily overlooked culprit is the air filter – when clogged, insufficient airflow makes the engine roar weakly. Finally, don't forget to check the exhaust pipe – once my car's issue turned out to be a deformed, obstructed exhaust.
