What causes shaking during rapid acceleration but not during gradual acceleration?
2 Answers
The reasons for shaking during rapid acceleration but not during gradual acceleration are: 1. Fuel system issues: Fuel line blockage causing poor fuel supply or fuel pump failure. To diagnose fuel pump problems, disconnect the fuel line and check the flow rate and volume of fuel; 2. Electrical issues: Check if the timing is accurate, inspect whether the spark plugs have aged, if the gaps are uniform, and if the gaps have changed; 3. Mechanical reasons: Check the engine's operating condition for any abnormal sounds, inspect the belt's working condition for looseness. A car engine consists of five major systems and two main mechanisms. The five systems are the fuel supply system, cooling system, lubrication system, ignition system, and starting system. The two mechanisms are the crankshaft and connecting rod mechanism and the valve train mechanism.
From my experience running a repair shop, sudden acceleration shaking is usually because the ignition system can't keep up. Old or dirty spark plugs may fail to produce a stronger spark needed during hard acceleration, causing severe engine vibration. The fuel system has similar issues – severely carbon-clogged fuel injectors or an insufficient fuel pump can't deliver enough fuel during rapid acceleration, disrupting the air-fuel mixture ratio and causing unstable engine operation. Gradual acceleration is fine because the power demand is steady and the system can cope. I recommend first checking and replacing spark plugs, cleaning fuel injectors, then testing fuel pump pressure. Don't overlook a dirty air filter affecting air intake – ensuring smooth combustion is key to completely solving vibration issues. Early detection and repair prevent minor issues from turning into major overhauls.
